Income Taxes - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended	12 Months Ended
	Feb. 29, 2016	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Remeasurement of net deferred tax liabilities		$ 140,000
Income Tax Receivable		100,023	$ 100,023	$ 11,884
Uncertain tax benefits that, if recognized, would affect effective tax rate		1,700	1,700	2,500
Recognized interest and penalties expense (benefit) related to unrecognized tax benefits			(600)	100	$ 400
Accrued interest and penalties		$ 300	$ 300	$ 900
Proceeds from refund of overpaid federal tax	$ 120,000