Income Taxes (Schedule of Income Tax Rate Reconciliation) (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
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Tax expense at Federal statutory rate									$ 18,518	$ 18,205	$ 27,174
Federal statutory rate									21.00%	21.00%	35.00%
(Decrease) increase in taxes resulting from:
Tax-exempt income, net									$ (814)	$ (809)	$ (1,313)
Tax-exempt income, net, rate									(0.90%)	(0.90%)	(1.70%)
Dividends received deduction									$ (36)	$ (45)	$ (55)
Dividends received deduction, rate									0.00%	(0.10%)	(0.10%)
BOLI									$ (494)	$ (461)	$ (757)
BOLI, rate									(0.60%)	(0.50%)	(0.90%)
Share-based compensation									$ (221)	$ (444)	$ (481)
Share-based compensation, rate									(0.30%)	(0.50%)	(0.60%)
Federal tax credits									$ (364)	$ (364)	$ (364)
Federal tax credits, rate									(0.40%)	(0.40%)	(0.50%)
Change in fair value of contingent consideration									$ 0	$ (39)	$ (225)
Change in fair value of contingent consideration, rate									0.00%	(0.10%)	(0.30%)
State income tax expense, net of federal tax benefit									$ 2,417	$ 2,162	$ 1,411
State income tax expense, net of federal income tax benefit, rate									2.70%	2.50%	1.80%
Adjustment to net deferred tax assets for enacted changes in federal tax law									$ 0	$ 0	$ 6,170
Adjustment to net deferred tax asset for enacted changes in federal tax law, rate									0.00%	0.00%	7.90%
Other									$ 55	$ 55	$ 155
Other, rate									0.10%	0.10%	0.20%
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
Effective tax rate									21.60%	21.10%	40.80%