Shareholders' Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Equity [Abstract]
Trust preferred securities included in Tier 1 Capital	$ 22,000	$ 22,000
Equity, Class of Treasury Stock [Line Items]
Treasury repurchase, shares	125,000
Amount of treasury repurchases	$ 4,322
Reserved Shares:
Reserved shares available for grant	1,625,598
Bank [Member]
Dividends:
Dividends paid by Bank to Bancorp	$ 43,139	$ 36,796	$ 32,394
2019 Stock Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Authorized amount (in shares)	850,000
Authorized amount as a percentage of total common stock	5.00%
Treasury repurchase, shares	124,863
Amount of treasury repurchases	$ 4,300
Average prices of treasury repurchases	$ 34.61
2020 Stock Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Authorized amount (in shares)	850,000
Authorized amount as a percentage of total common stock	5.00%