Income Taxes (Details 3) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income (loss) from continuing operations before income taxes	$ 33,760	$ (56,352)	$ 13,236	$ (10,182)	$ 28,119	$ 7,263	$ 15,447	$ (26,298)	$ (19,538)	$ 24,531	$ 76,346
U.S. federal statutory rate									35.00%	35.00%	35.00%
Provision at statutory rate									$ (6,838)	$ 8,586	$ 26,721
State income taxes—net of federal benefit									401	(498)	1,701
Effect of rates other than statutory									(3,842)	(1,966)	(2,306)
Effect of U.S. taxation on foreign branches									15,710	8,854	10,366
Foreign tax adjustment, prior years									0	0	7
Noncontrolling interest									0	3,908	4,373
Foreign tax credit and offset to branch deferreds									45,245	(6,026)	(1,740)
Effective Income Tax Rate Reconciliation, Tax Credit, Foreign, Amount									(7,514)	0	0
Impact of valuation allowance on deferred tax assets									(65,327)	6,026	1,740
Foreign withholding taxes									858	18	6
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Compensation Cost, Amount									1,351	0	0
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount									17,638	0	0
Other, net									(70)	182	1,408
Provision (benefit) for income taxes	$ 31,141	$ (37,249)	$ 3,625	$ 95	$ 16,119	$ 11,898	$ 4,658	$ (21,407)	$ (2,388)	$ 11,268	$ 33,530