GUARANTORS OF SECURITIES Supplemental Condensed Consolidating Statements of Cash Flows (Details) - USD ($)
$ in Thousands |
12 Months Ended |
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
| Condensed Cash Flow Statements, Captions [Line Items] |
|
|
|
| Net cash provided by operating activities |
$ 54,354
|
$ 20,096
|
$ 58,504
|
| Cash flows from investing activities: |
|
|
|
| Purchases of property and equipment |
(9,216)
|
(16,770)
|
(39,200)
|
| Proceeds from disposition of property and equipment |
29,590
|
9,392
|
28,609
|
| Increase (Decrease) in Dividends Receivable |
(1,000)
|
|
|
| Return of helicopter deposits |
0
|
0
|
544
|
| Investments in and advances to equity investees |
0
|
(126)
|
0
|
| Principal payments on notes due from equity investees |
518
|
761
|
723
|
| Principal payments on third party notes receivable |
934
|
169
|
208
|
| Escrow deposits on like-kind exchanges, net |
|
0
|
0
|
| Repayment of intercompany debt |
|
|
0
|
| Net cash provided by (used in) investing activities |
22,826
|
(6,574)
|
(9,116)
|
| Cash flows from financing activities: |
|
|
|
| Proceeds from Revolving Credit Facility |
0
|
17,000
|
12,000
|
| Long-term debt issuance costs |
(1,295)
|
0
|
(886)
|
| Payments on long-term debt |
(41,886)
|
(45,281)
|
(40,444)
|
| Extinguishment of long-term debt |
(1,221)
|
0
|
(4,331)
|
| Proceeds and tax benefits from share award plans |
893
|
836
|
836
|
| Purchase of treasury shares |
0
|
(52)
|
(161)
|
| Borrowings and repayments of intercompany debt |
0
|
0
|
0
|
| Net cash used in financing activities |
(43,509)
|
(27,497)
|
(32,986)
|
| Effects of exchange rate changes on cash, cash equivalents and restricted cash |
249
|
81
|
(236)
|
| Net increase (decrease) in cash, cash equivalents and restricted cash |
33,920
|
(13,894)
|
16,166
|
| Cash, cash equivalents and restricted cash, beginning of year |
16,833
|
30,727
|
14,561
|
| Cash, cash equivalents and restricted cash, end of year |
50,753
|
16,833
|
30,727
|
| Reportable Legal Entities | Parent |
|
|
|
| Condensed Cash Flow Statements, Captions [Line Items] |
|
|
|
| Net cash provided by operating activities |
37,596
|
(14,706)
|
17,909
|
| Cash flows from investing activities: |
|
|
|
| Purchases of property and equipment |
0
|
0
|
0
|
| Proceeds from disposition of property and equipment |
0
|
0
|
0
|
| Increase (Decrease) in Dividends Receivable |
0
|
|
|
| Return of helicopter deposits |
|
|
0
|
| Investments in and advances to equity investees |
|
0
|
|
| Principal payments on notes due from equity investees |
0
|
0
|
0
|
| Principal payments on third party notes receivable |
0
|
0
|
0
|
| Escrow deposits on like-kind exchanges, net |
|
0
|
0
|
| Repayment of intercompany debt |
|
|
0
|
| Net cash provided by (used in) investing activities |
0
|
0
|
0
|
| Cash flows from financing activities: |
|
|
|
| Proceeds from Revolving Credit Facility |
|
0
|
0
|
| Long-term debt issuance costs |
0
|
|
0
|
| Payments on long-term debt |
0
|
0
|
0
|
| Extinguishment of long-term debt |
0
|
|
0
|
| Proceeds and tax benefits from share award plans |
0
|
0
|
0
|
| Purchase of treasury shares |
|
0
|
0
|
| Borrowings and repayments of intercompany debt |
0
|
0
|
0
|
| Net cash used in financing activities |
0
|
0
|
0
|
| Effects of exchange rate changes on cash, cash equivalents and restricted cash |
0
|
32
|
0
|
| Net increase (decrease) in cash, cash equivalents and restricted cash |
37,596
|
(14,674)
|
17,909
|
| Cash, cash equivalents and restricted cash, beginning of year |
10,800
|
25,474
|
7,565
|
| Cash, cash equivalents and restricted cash, end of year |
48,396
|
10,800
|
25,474
|
| Reportable Legal Entities | Guarantors |
|
|
|
| Condensed Cash Flow Statements, Captions [Line Items] |
|
|
|
| Net cash provided by operating activities |
14,639
|
32,601
|
41,239
|
| Cash flows from investing activities: |
|
|
|
| Purchases of property and equipment |
(8,867)
|
(16,600)
|
(39,020)
|
| Proceeds from disposition of property and equipment |
29,590
|
9,392
|
28,381
|
| Increase (Decrease) in Dividends Receivable |
(1,000)
|
|
|
| Return of helicopter deposits |
|
|
544
|
| Investments in and advances to equity investees |
|
(126)
|
|
| Principal payments on notes due from equity investees |
518
|
761
|
723
|
| Principal payments on third party notes receivable |
934
|
169
|
208
|
| Escrow deposits on like-kind exchanges, net |
|
0
|
0
|
| Repayment of intercompany debt |
|
|
0
|
| Net cash provided by (used in) investing activities |
23,175
|
(6,404)
|
(9,164)
|
| Cash flows from financing activities: |
|
|
|
| Proceeds from Revolving Credit Facility |
|
8,000
|
0
|
| Long-term debt issuance costs |
0
|
|
0
|
| Payments on long-term debt |
(1,662)
|
(1,526)
|
(1,803)
|
| Extinguishment of long-term debt |
0
|
|
0
|
| Proceeds and tax benefits from share award plans |
0
|
0
|
0
|
| Purchase of treasury shares |
|
0
|
0
|
| Borrowings and repayments of intercompany debt |
(39,402)
|
(33,216)
|
(29,542)
|
| Net cash used in financing activities |
(41,064)
|
(26,742)
|
(31,345)
|
| Effects of exchange rate changes on cash, cash equivalents and restricted cash |
0
|
18
|
(478)
|
| Net increase (decrease) in cash, cash equivalents and restricted cash |
(3,250)
|
(527)
|
252
|
| Cash, cash equivalents and restricted cash, beginning of year |
3,250
|
3,777
|
3,525
|
| Cash, cash equivalents and restricted cash, end of year |
0
|
3,250
|
3,777
|
| Reportable Legal Entities | Non-guarantors |
|
|
|
| Condensed Cash Flow Statements, Captions [Line Items] |
|
|
|
| Net cash provided by operating activities |
2,119
|
2,201
|
(644)
|
| Cash flows from investing activities: |
|
|
|
| Purchases of property and equipment |
(349)
|
(170)
|
(180)
|
| Proceeds from disposition of property and equipment |
0
|
0
|
228
|
| Increase (Decrease) in Dividends Receivable |
0
|
|
|
| Return of helicopter deposits |
|
|
0
|
| Investments in and advances to equity investees |
|
0
|
|
| Principal payments on notes due from equity investees |
0
|
0
|
0
|
| Principal payments on third party notes receivable |
0
|
0
|
0
|
| Escrow deposits on like-kind exchanges, net |
|
0
|
0
|
| Repayment of intercompany debt |
|
|
0
|
| Net cash provided by (used in) investing activities |
(349)
|
(170)
|
48
|
| Cash flows from financing activities: |
|
|
|
| Proceeds from Revolving Credit Facility |
|
0
|
0
|
| Long-term debt issuance costs |
0
|
|
0
|
| Payments on long-term debt |
(1,224)
|
(755)
|
(1,641)
|
| Extinguishment of long-term debt |
(1,221)
|
|
0
|
| Proceeds and tax benefits from share award plans |
0
|
0
|
0
|
| Purchase of treasury shares |
|
0
|
0
|
| Borrowings and repayments of intercompany debt |
0
|
0
|
0
|
| Net cash used in financing activities |
(2,445)
|
(755)
|
(1,641)
|
| Effects of exchange rate changes on cash, cash equivalents and restricted cash |
249
|
31
|
242
|
| Net increase (decrease) in cash, cash equivalents and restricted cash |
(426)
|
1,307
|
(1,995)
|
| Cash, cash equivalents and restricted cash, beginning of year |
2,783
|
1,476
|
3,471
|
| Cash, cash equivalents and restricted cash, end of year |
2,357
|
2,783
|
1,476
|
| Eliminations |
|
|
|
| Condensed Cash Flow Statements, Captions [Line Items] |
|
|
|
| Net cash provided by operating activities |
0
|
0
|
0
|
| Cash flows from investing activities: |
|
|
|
| Purchases of property and equipment |
0
|
0
|
0
|
| Proceeds from disposition of property and equipment |
0
|
0
|
0
|
| Increase (Decrease) in Dividends Receivable |
0
|
|
|
| Return of helicopter deposits |
|
|
0
|
| Investments in and advances to equity investees |
|
0
|
|
| Principal payments on notes due from equity investees |
0
|
0
|
0
|
| Principal payments on third party notes receivable |
0
|
0
|
0
|
| Escrow deposits on like-kind exchanges, net |
|
0
|
0
|
| Repayment of intercompany debt |
|
|
0
|
| Net cash provided by (used in) investing activities |
0
|
0
|
0
|
| Cash flows from financing activities: |
|
|
|
| Proceeds from Revolving Credit Facility |
|
9,000
|
12,000
|
| Long-term debt issuance costs |
(1,295)
|
|
(886)
|
| Payments on long-term debt |
(39,000)
|
(43,000)
|
(37,000)
|
| Extinguishment of long-term debt |
0
|
|
(4,331)
|
| Proceeds and tax benefits from share award plans |
893
|
836
|
836
|
| Purchase of treasury shares |
|
(52)
|
(161)
|
| Borrowings and repayments of intercompany debt |
39,402
|
33,216
|
29,542
|
| Net cash used in financing activities |
0
|
0
|
0
|
| Effects of exchange rate changes on cash, cash equivalents and restricted cash |
0
|
0
|
0
|
| Net increase (decrease) in cash, cash equivalents and restricted cash |
0
|
0
|
0
|
| Cash, cash equivalents and restricted cash, beginning of year |
0
|
0
|
0
|
| Cash, cash equivalents and restricted cash, end of year |
$ 0
|
$ 0
|
$ 0
|