Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Effective Income Tax Rate, Percent	25.90%	39.40%	18.40%	32.80%
Valuation Allowance [Abstract]
Valuation Allowance, Amount	$ 0		$ 0		$ 0
Income Tax Uncertainties [Abstract]
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	3,400		3,400		4,800
Unrecognized Tax Benefits, Period Increase (Decrease)	300	$ (100)	(1,600)	$ (2,900)
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	900		900		$ 2,300
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	100	$ (0)	(1,400)	$ (1,300)
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance beginning of period			5,839
Additions based on tax positions related to current year			394
Additions for tax positions of prior years			0
Reductions for tax positions of prior years			0
Reductions due to lapse of applicable statute of limitations			(1,954)
Settlements			0
Balance end of period	4,279		4,279
Maximum [Member]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Lower Bound	(800)		(800)
Minimum [Member]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Lower Bound	$ (200)		$ (200)