Income Taxes (Schedule of Components of Income Tax Expense) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current tax expense:
Federal									$ 17,298	$ 15,460	$ 23,827
State									3,254	2,863	2,201
Total current tax expense									20,552	18,323	26,028
Deferred tax (benefit) expense:
Federal									(1,294)	63	5,717
State									(197)	(126)	(30)
Total deferred (benefit) tax expense									(1,491)	(63)	5,687
Total income tax expense	$ 4,321	$ 5,236	$ 4,662	$ 4,842	$ 4,523	$ 4,741	$ 4,742	$ 4,254	$ 19,061	$ 18,260	$ 31,715