Repurchase Agreements (Details) - Securities Sold under Agreements to Repurchase [Member] - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Financial Instruments Pledged as Collateral [Abstract]
Carrying value of investment securities available-for-sale pledged as collateral under repurchase agreements	$ 393,300	$ 397,400
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	292,022	355,862
Overnight and Continuous [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	115,268	96,456
Up to 30 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	31,000	0
30-90 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	17,947	105,000
Greater Than 90 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	127,807	154,406
U.S. Treasury and Government Agencies [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	21,184	43,408
U.S. Treasury and Government Agencies [Member] | Overnight and Continuous [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	6,183	8,777
U.S. Treasury and Government Agencies [Member] | Up to 30 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	7,734	0
U.S. Treasury and Government Agencies [Member] | 30-90 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	0	2,831
U.S. Treasury and Government Agencies [Member] | Greater Than 90 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	7,267	31,800
State and Political Subdivisions [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	100,548	77,192
State and Political Subdivisions [Member] | Overnight and Continuous [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	75,188	54,639
State and Political Subdivisions [Member] | Up to 30 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	4,534	0
State and Political Subdivisions [Member] | 30-90 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	6,224	1,132
State and Political Subdivisions [Member] | Greater Than 90 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	14,602	21,421
U.S. Government Sponsored Agency Mortgage-backed Securities [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	170,290	235,262
U.S. Government Sponsored Agency Mortgage-backed Securities [Member] | Overnight and Continuous [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	33,897	33,040
U.S. Government Sponsored Agency Mortgage-backed Securities [Member] | Up to 30 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	18,732	0
U.S. Government Sponsored Agency Mortgage-backed Securities [Member] | 30-90 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	11,723	101,037
U.S. Government Sponsored Agency Mortgage-backed Securities [Member] | Greater Than 90 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	$ 105,938	$ 101,185