Income Taxes (Components of Income Tax Expense (Benefit)) (Details) - USD ($) $ in Thousands	3 Months Ended									12 Months Ended
	Dec. 31, 2017	[1]	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:
Federal										$ 4,250		$ 6,456	$ 6,825
State										1,638		941	1,290
Deferred:
Federal										4,256		301	(84)
State										(259)		18	(53)
Total income tax expense	$ 3,576		$ 2,396	$ 2,248	$ 1,665	$ 1,806	$ 1,855	$ 2,035	$ 2,020	$ 9,885	[1]	$ 7,716	$ 7,978

[1] Includes one-time, non-cash TCJA charge of $1,824,000