Derivative Financial Instruments, Type of Hedge and Fair Value of Derivative Instruments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended	12 Months Ended
	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Dec. 31, 2020
Fair value of derivative instruments, balance sheet location [Abstract]
Asset Derivatives			$ 13,559	$ 16,782
Liability Derivatives			6,583	11,754
Interest-Rate Cap Agreements [Member]
Derivative financial instrument according to type of hedge [Abstract]
Unrealized loss on derivative instrument to be reclassified into earnings	$ (500)	$ (2,000)
Fair Value Hedge Designation [Member]
Derivative financial instrument according to type of hedge [Abstract]
Notional Amount			$ 155,734	$ 49,038
Average Maturity			6 years 2 months 12 days	7 years 3 months 18 days
Fair Value			$ 2,818	$ (761)
No Hedge Designation [Member]
Derivative financial instrument according to type of hedge [Abstract]
Notional Amount			$ 808,349	$ 815,576
Average Maturity			2 years 2 months 12 days	2 years
Fair Value			$ 4,158	$ 5,789
Fair value of derivative instruments, balance sheet location [Abstract]
Asset Derivatives			10,288	16,767
Liability Derivatives			6,130	10,978
No Hedge Designation [Member] | Rate-Lock Mortgage Loan Commitments [Member]
Derivative financial instrument according to type of hedge [Abstract]
Notional Amount			$ 184,611	$ 168,816
Average Maturity			1 month 6 days	1 month 6 days
Fair Value			$ 3,535	$ 7,020
No Hedge Designation [Member] | Mandatory Commitments to Sell Mortgage Loans [Member]
Derivative financial instrument according to type of hedge [Abstract]
Notional Amount			$ 158,546	$ 186,092
Average Maturity			1 month 6 days	1 month 6 days
Fair Value			$ 448	$ (941)
No Hedge Designation [Member] | Interest Rate Swaption Agreement [Member]
Derivative financial instrument according to type of hedge [Abstract]
Notional Amount			$ 10,000
Average Maturity			6 months
Fair Value			$ 164
No Hedge Designation [Member] | Interest-Rate Cap Agreements [Member]
Derivative financial instrument according to type of hedge [Abstract]
Notional Amount			$ 120,000	$ 135,000
Average Maturity			1 year 2 months 12 days	1 year 9 months 18 days
Fair Value			$ 11	$ 5
No Hedge Designation [Member] | Purchased Options [Member]
Derivative financial instrument according to type of hedge [Abstract]
Notional Amount			$ 393	$ 2,908
Average Maturity			2 months 12 days	6 months
Fair Value			$ 1	$ 42
No Hedge Designation [Member] | Written Options [Member]
Derivative financial instrument according to type of hedge [Abstract]
Notional Amount			$ 393	$ 2,848
Average Maturity			2 months 12 days	6 months
Fair Value			$ (1)	$ (42)
Fixed Income Interest Rate [Member] | Fair Value Hedge Designation [Member] | Interest Rate Swap [Member]
Derivative financial instrument according to type of hedge [Abstract]
Notional Amount			$ 6,839	$ 7,088
Average Maturity			7 years 7 months 6 days	8 years 4 months 24 days
Fair Value			$ (453)	$ (776)
Fixed Income Interest Rate [Member] | Fair Value Hedge Designation [Member] | Interest Rate Swap [Member]
Derivative financial instrument according to type of hedge [Abstract]
Notional Amount			$ 148,895	$ 41,950
Average Maturity			6 years 1 month 6 days	7 years 1 month 6 days
Fair Value			$ 3,271	$ 15
Fixed Income Interest Rate [Member] | No Hedge Designation [Member] | Interest Rate Swap [Member]
Derivative financial instrument according to type of hedge [Abstract]
Notional Amount			$ 167,203	$ 147,456
Average Maturity			4 years 8 months 12 days	4 years 6 months
Fair Value			$ (5,965)	$ (9,700)
Fixed Income Interest Rate [Member] | No Hedge Designation [Member] | Interest Rate Swap [Member]
Derivative financial instrument according to type of hedge [Abstract]
Notional Amount				$ 25,000
Average Maturity				7 months 6 days
Fair Value				$ (295)
Variable Income Interest Rate [Member] | No Hedge Designation [Member] | Interest Rate Swap [Member]
Derivative financial instrument according to type of hedge [Abstract]
Notional Amount			$ 167,203	$ 147,456
Average Maturity			4 years 8 months 12 days	4 years 6 months
Fair Value			$ 5,965	$ 9,700
Other Assets [Member] | No Hedge Designation [Member] | Rate-Lock Mortgage Loan Commitments [Member]
Fair value of derivative instruments, balance sheet location [Abstract]
Asset Derivatives			3,535	7,020
Other Assets [Member] | No Hedge Designation [Member] | Mandatory Commitments to Sell Mortgage Loans [Member]
Fair value of derivative instruments, balance sheet location [Abstract]
Asset Derivatives			448	0
Other Assets [Member] | No Hedge Designation [Member] | Interest Rate Swaption Agreement [Member]
Fair value of derivative instruments, balance sheet location [Abstract]
Asset Derivatives			164	0
Other Assets [Member] | No Hedge Designation [Member] | Interest-Rate Cap Agreements [Member]
Fair value of derivative instruments, balance sheet location [Abstract]
Asset Derivatives			11	5
Other Assets [Member] | No Hedge Designation [Member] | Purchased Options [Member]
Fair value of derivative instruments, balance sheet location [Abstract]
Asset Derivatives			1	42
Other Assets [Member] | No Hedge Designation [Member] | Written Options [Member]
Fair value of derivative instruments, balance sheet location [Abstract]
Asset Derivatives			0	0
Other Assets [Member] | Fixed Income Interest Rate [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Fair value of derivative instruments, balance sheet location [Abstract]
Asset Derivatives			3,271	15
Other Assets [Member] | Fixed Income Interest Rate [Member] | No Hedge Designation [Member] | Interest Rate Swap [Member]
Fair value of derivative instruments, balance sheet location [Abstract]
Asset Derivatives			82	0
Other Assets [Member] | Fixed Income Interest Rate [Member] | No Hedge Designation [Member] | Interest Rate Swap [Member]
Fair value of derivative instruments, balance sheet location [Abstract]
Asset Derivatives			0	0
Other Assets [Member] | Variable Income Interest Rate [Member] | No Hedge Designation [Member] | Interest Rate Swap [Member]
Fair value of derivative instruments, balance sheet location [Abstract]
Asset Derivatives			6,047	9,700
Other Liabilities [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Fair value of derivative instruments, balance sheet location [Abstract]
Liability Derivatives				776
Other Liabilities [Member] | No Hedge Designation [Member] | Rate-Lock Mortgage Loan Commitments [Member]
Fair value of derivative instruments, balance sheet location [Abstract]
Liability Derivatives			0	0
Other Liabilities [Member] | No Hedge Designation [Member] | Mandatory Commitments to Sell Mortgage Loans [Member]
Fair value of derivative instruments, balance sheet location [Abstract]
Liability Derivatives			0	941
Other Liabilities [Member] | No Hedge Designation [Member] | Interest Rate Swaption Agreement [Member]
Fair value of derivative instruments, balance sheet location [Abstract]
Liability Derivatives			0	0
Other Liabilities [Member] | No Hedge Designation [Member] | Interest-Rate Cap Agreements [Member]
Fair value of derivative instruments, balance sheet location [Abstract]
Liability Derivatives			0	0
Other Liabilities [Member] | No Hedge Designation [Member] | Purchased Options [Member]
Fair value of derivative instruments, balance sheet location [Abstract]
Liability Derivatives			0	0
Other Liabilities [Member] | No Hedge Designation [Member] | Written Options [Member]
Fair value of derivative instruments, balance sheet location [Abstract]
Liability Derivatives			1	42
Other Liabilities [Member] | Fixed Income Interest Rate [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Fair value of derivative instruments, balance sheet location [Abstract]
Liability Derivatives			453
Other Liabilities [Member] | Fixed Income Interest Rate [Member] | No Hedge Designation [Member] | Interest Rate Swap [Member]
Fair value of derivative instruments, balance sheet location [Abstract]
Liability Derivatives			6,047	9,700
Other Liabilities [Member] | Fixed Income Interest Rate [Member] | No Hedge Designation [Member] | Interest Rate Swap [Member]
Fair value of derivative instruments, balance sheet location [Abstract]
Liability Derivatives			0	295
Other Liabilities [Member] | Variable Income Interest Rate [Member] | No Hedge Designation [Member] | Interest Rate Swap [Member]
Fair value of derivative instruments, balance sheet location [Abstract]
Liability Derivatives			$ 82	$ 0