NATURE OF OPERATIONS AND ACCOUNTING POLICIES - ERA Savings Plan (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
| Organization, Consolidation and Presentation of Financial Statements [Abstract] | |||
| Percent of employer contribution | 3.00% | ||
| Employer matching contribution, percent | 100.00% | ||
| Employer matching contribution, percent of employees' gross pay | 3.00% | ||
| Employer contribution | $ 2.3 | $ 2.4 | $ 2.8 |
| X | ||||||||||
- Definition Defined Contribution Plan, Percent of Employees' Gross Pay No definition available.
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| X | ||||||||||
- Definition Amount of discretionary contributions made by an employer to a defined contribution plan. No definition available.
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| X | ||||||||||
- Definition Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan. No definition available.
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| X | ||||||||||
- Definition Percentage employer matches of the employee's percentage contribution matched. No definition available.
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| X | ||||||||||
- References No definition available.
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