Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Abstract]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%
Income Tax Reconciliation, Other Adjustments		$ 577	$ (109)	$ (165)
Deferred Income Tax Expense (Benefit)		$ (27,177)	(5,455)	7,648
PortionOfTaxBenefitRecordedPositionsMoreLikelyThanNotToBeSustained		50.00%
Income Tax Uncertainties [Abstract]
Unrecognized Tax Benefits that Would Impact Effective Tax Rate		$ 4,800	5,700
Unrecognized Tax Benefits, Period Increase (Decrease)		(2,900)	(2,800)
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued		2,300	3,200
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense		(900)	(1,500)	(1,000)
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Lower Bound		(2,200)
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Upper Bound		(3,200)
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance beginning of period	$ 5,839	8,751	11,569
Additions based on tax positions related to current year		135	592
Additions for tax positions of prior years		0	0
Reductions for tax positions of prior years		(331)	(108)
Reductions due to lapse of applicable statute of limitations		(2,699)	(3,302)
Settlements		(17)	0
Balance end of period		5,839	8,751	11,569
Valuation Allowance [Abstract]
Valuation Allowance, Amount		0	0
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Change in Tax Rate, Deferred TaxLiability, Provisional Income Tax (Expense) Benefit		$ 32,789	$ 0	$ 0