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]
Benefit from income taxes	$ (1,644)	$ (9,233)
Effective tax rate	(1.20%)	(12.50%)
Provisional income tax expense (benefit)			$ 51,800
Benefit from income taxes	$ 1,644	$ 9,233