Income Taxes - Provision (benefit) for income taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
Federal	$ 31,200	$ 33,600	$ 42,600
State	6,500	6,400	5,100
Foreign	1,900	2,100	2,900
Current Income Tax Expense	39,600	42,100	50,600
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Federal	(3,800)	(7,800)	(131,000)
State	(1,700)	(4,000)	(5,100)
Deferred income tax expense (benefit)	(5,494)	(11,847)	(136,127)
Provision (benefit) for income taxes	$ 34,127	$ 30,254	$ (85,559)