Income Taxes (Detail Textuals) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Loss Carryforwards [Line Items]
Undistributed earnings of foreign subsidiaries	$ 10,200
Deferred tax assets, valuation allowance	356	$ 276
Total net income tax (refunds) payments	(42,400)	(7,900)	$ 152,200
Accrued interest and penalties	76	$ 411
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards related to state income taxes	33,500
Deferred tax assets, valuation allowance	$ 356