Income Taxes - Narratives (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Contingency
Net operating loss and other tax credit carryforwards	$ 31,381	$ 19,553
Valuation allowance	27,350	29,746
Deferred tax asset	14,000	12,600
Deferred income taxes	90,825	86,104
Accrued interest related to uncertain tax positions	1,100
Income taxes paid	$ 19,300	49,200	$ 25,200
Maximum
Income Tax Contingency
Open tax years by major jurisdictions	2012
Minimum
Income Tax Contingency
Open tax years by major jurisdictions	2016
Federal
Income Tax Contingency
Operating loss carryforwards, initial expiration date	Dec. 31, 2034
Foreign
Income Tax Contingency
Operating loss carryforwards, initial expiration date	Dec. 31, 2017
Income Tax Expense
Income Tax Contingency
Prior period adjustment	$ 3,000
Windfall Tax
Income Tax Contingency
Income taxes paid	$ 26,000	$ 61,700	$ 30,900