Income Taxes - Summary of Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current Income Tax Expense:
Federal	$ 103,993	$ 32,999	$ 41,946
State	10,308	5,442	8,682
Current Income Tax Expense (Benefit), Total	114,301	38,441	50,628
Deferred Income Tax (Benefit) Expense:
Federal	(33,470)	35,413	(3,314)
State	(1,692)	3,557	(3,843)
Deferred Income Tax Expense (Benefit), Total	(35,162)	38,970	(7,157)
INCOME TAXES	$ 79,139	$ 77,411	$ 43,471