Income Taxes - Income Tax Expense (Benefit) Attributable to Income from Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current
Federal	$ 16,391	$ 26,860	$ 22,943
State	3,060	1,162	2,243
Total	19,451	28,022	25,186
Deferred
Federal	2,281	14,749	1,551
State	73	(151)	308
Deferred tax expense	2,354	14,598	1,859
Federal Total	18,672	41,609	24,494
State Total	3,133	1,011	2,551
Tax expense (benefit)	$ 21,805	$ 42,620	$ 27,045