Income Taxes, Current and Deferred 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
Current [Abstract]
Federal									$ 9,460	$ 13,101	$ 11,979
State									4,046	4,832	4,446
Total Current									13,506	17,933	16,425
Deferred [Abstract]
Federal									11,154	(1,607)	383
State									1,451	(229)	116
Total Deferred									12,605	(1,836)	499
Total Provision for Taxes	$ 11,974	$ 5,000	$ 4,708	$ 4,429	$ 3,389	$ 4,503	$ 4,169	$ 4,036	$ 26,111	$ 16,097	$ 16,924