Income Taxes - Schedule of Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Examination [Line Items]
Federal									$ 15,845	$ 17,005	$ 22,916
State and local									1,377	1,734	2,798
Current Federal, State and Local, Tax Expense (Benefit)									17,222	18,739	25,714
Deferred:									21,105	7,263	(5,763)
Deferred Federal Income Tax Expense (Benefit)									20,989	5,959	(5,266)
Deferred State and Local Income Tax Expense (Benefit)									116	1,304	(497)
Deferred Federal, State and Local, Tax Expense (Benefit)									21,105	7,263	(5,763)
Total income tax expense	$ 19,820	$ 7,856	$ 5,545	$ 5,106	$ 7,053	$ 6,316	$ 6,747	$ 5,886	$ 38,327	$ 26,002	$ 19,951