Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income tax provision	$ 9,790	$ 5,066
Effective income tax rate (as a percent)	20.90%	33.60%
Statutory U.S. income tax rate (as a percent)	21.00%	35.00%	35.00%
Income taxes paid (refunds), net	$ (12,000)	$ 100
Tax Cuts and Jobs Act of 2017 Incomplete Accounting Provisional Income Tax Expense and Benefit			$ (8,100)