Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Current tax expense (benefit):
Income tax provision	$ 12,993	$ 54,495
Current income tax expense (benefit)	40,200
Deferred tax expense (benefit):
Deferred income taxes	192	$ (227)
Deferred Income Tax Expense (Benefit), Excluding Discontinued Operations	$ 53,500