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Long-Term Compensation Plan and Stock Based Compensation - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018	Mar. 31, 2018
Restricted Stock, subject to performance criteria
Long-Term Compensation Plan and Stock Based Compensation
Unissued shares	161,000	161,000
Restricted Stock, subject to time-based criteria
Long-Term Compensation Plan and Stock Based Compensation
Stock based compensation awards issued shares		163,000
2009 Equity Incentive Plan
Long-Term Compensation Plan and Stock Based Compensation
Stock based compensation awards issued shares	0
2009 Equity Incentive Plan \| Restricted Stock
Long-Term Compensation Plan and Stock Based Compensation
Stock based compensation Awards			324
2009 Equity Incentive Plan \| Restricted Stock, subject to performance criteria
Long-Term Compensation Plan and Stock Based Compensation
Unissued shares	161,000	161,000
Vesting period (in years)		3 years
Fair value of nonvested awards		$ 2,280
2009 Equity Incentive Plan \| Restricted Stock, subject to time-based criteria
Long-Term Compensation Plan and Stock Based Compensation
Stock based compensation awards issued shares		163,000
Restricted stock awards, fair value		$ 2,299
2009 Equity Incentive Plan \| Restricted Stock, subject to time-based criteria \| Minimum
Long-Term Compensation Plan and Stock Based Compensation
Vesting period (in years)		1 year
2009 Equity Incentive Plan \| Restricted Stock, subject to time-based criteria \| Maximum
Long-Term Compensation Plan and Stock Based Compensation
Vesting period (in years)		4 years