Annual report pursuant to Section 13 and 15(d)

QUARTERLY FINANCIAL INFORMATION (UNAUDITED) QUARTERLY FINANCIAL INFORMATION (UNAUDITED) (Details)

v2.4.1.9
QUARTERLY FINANCIAL INFORMATION (UNAUDITED) QUARTERLY FINANCIAL INFORMATION (UNAUDITED) (Details) (USD $)
In Thousands, except Per Share data, unless otherwise specified
3 Months Ended 12 Months Ended
Dec. 31, 2014
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2014
Dec. 31, 2013
Sep. 30, 2013
Jun. 30, 2013
Mar. 31, 2013
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract]                      
Operating revenues $ 74,689us-gaap_Revenues $ 90,510us-gaap_Revenues $ 86,580us-gaap_Revenues $ 79,443us-gaap_Revenues $ 75,998us-gaap_Revenues $ 80,997us-gaap_Revenues $ 74,237us-gaap_Revenues $ 67,727us-gaap_Revenues $ 331,222us-gaap_Revenues $ 298,959us-gaap_Revenues $ 272,921us-gaap_Revenues
Operating income 7,445us-gaap_OperatingIncomeLoss 11,583us-gaap_OperatingIncomeLoss 13,550us-gaap_OperatingIncomeLoss 10,073us-gaap_OperatingIncomeLoss 9,558us-gaap_OperatingIncomeLoss 11,196us-gaap_OperatingIncomeLoss 10,792us-gaap_OperatingIncomeLoss 14,617us-gaap_OperatingIncomeLoss 42,651us-gaap_OperatingIncomeLoss 46,163us-gaap_OperatingIncomeLoss 32,051us-gaap_OperatingIncomeLoss
Net income 3,140us-gaap_ProfitLoss 4,311us-gaap_ProfitLoss 5,196us-gaap_ProfitLoss 4,374us-gaap_ProfitLoss 1,677us-gaap_ProfitLoss 5,088us-gaap_ProfitLoss 4,950us-gaap_ProfitLoss 6,589us-gaap_ProfitLoss 17,021us-gaap_ProfitLoss 18,304us-gaap_ProfitLoss 7,747us-gaap_ProfitLoss
Net income attributable to common shares $ 3,185us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ 4,266us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ 5,221us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ 4,445us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ 1,752us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ 5,204us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ 5,055us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ 5,973us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ 17,117us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ 17,984us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ (682)us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic
Basic Earnings Per Common Share (in dollars per share) $ 0.16us-gaap_EarningsPerShareBasic $ 0.21us-gaap_EarningsPerShareBasic $ 0.26us-gaap_EarningsPerShareBasic $ 0.22us-gaap_EarningsPerShareBasic $ 0.09us-gaap_EarningsPerShareBasic $ 0.26us-gaap_EarningsPerShareBasic $ 0.25us-gaap_EarningsPerShareBasic $ 0.28us-gaap_EarningsPerShareBasic $ 0.84us-gaap_EarningsPerShareBasic $ 0.88us-gaap_EarningsPerShareBasic $ (0.03)us-gaap_EarningsPerShareBasic
Diluted Earnings Per Common Share (in dollars per share) $ 0.16us-gaap_EarningsPerShareDiluted $ 0.21us-gaap_EarningsPerShareDiluted $ 0.26us-gaap_EarningsPerShareDiluted $ 0.22us-gaap_EarningsPerShareDiluted $ 0.09us-gaap_EarningsPerShareDiluted $ 0.26us-gaap_EarningsPerShareDiluted $ 0.25us-gaap_EarningsPerShareDiluted $ 0.28us-gaap_EarningsPerShareDiluted $ 0.84us-gaap_EarningsPerShareDiluted $ 0.88us-gaap_EarningsPerShareDiluted $ (0.03)us-gaap_EarningsPerShareDiluted