Parent Company Financial Information (Condensed Balance Sheets) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Assets:
Deferred income tax benefit	$ 317	$ 3,447
Other assets	15,401	16,143
Total assets	4,097,843	4,241,060
Liabilities:
Cash dividends payable	4,308	4,456	$ 3,798
Total liabilities	3,708,735	3,852,873
Stockholders' Equity:
Common stock	2,393	2,542
Surplus	111,744	145,163
Retained earnings	274,376	249,922
Total	388,513	397,627
Accumulated other comprehensive income (loss), net of tax	595	(9,440)
Total	389,108	388,187	354,450	$ 305,830
Total	4,097,843	4,241,060
Parent Company [Member]
Assets:
Cash and due from banks	1,719	583
Investment in subsidiary bank, at equity	388,965	390,388
Prepaid income taxes	805
Deferred income tax benefit	1,917	1,924
Other assets	25	80
Total assets	393,431	392,975
Liabilities:
Other liabilities	15	332
Cash dividends payable	4,308	4,456	$ 3,798
Total liabilities	4,323	4,788
Stockholders' Equity:
Common stock	2,393	2,542
Surplus	111,744	145,163
Retained earnings	274,376	249,922
Total	388,513	397,627
Accumulated other comprehensive income (loss), net of tax	595	(9,440)
Total	389,108	388,187
Total	$ 393,431	$ 392,975