Derivative Financial Instruments (Details) - USD ($) $ in Thousands	3 Months Ended			12 Months Ended
	Mar. 31, 2021	Sep. 30, 2020	Mar. 31, 2020	Dec. 31, 2020
Fair value of derivative instruments, balance sheet location [Abstract]
Asset Derivatives	$ 15,766			$ 16,782
Liability Derivatives	7,365			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	$ 155,900			$ 49,038
Average Maturity	6 years 8 months 12 days			7 years 3 months 18 days
Fair Value	$ 4,464			$ (761)
No Hedge Designation [Member]
Derivative financial instrument according to type of hedge [Abstract]
Notional Amount	$ 816,485			$ 815,576
Average Maturity	1 year 10 months 24 days			2 years
Fair Value	$ 3,937			$ 5,789
Fair value of derivative instruments, balance sheet location [Abstract]
Asset Derivatives	10,879			16,767
Liability Derivatives	6,942			10,978
No Hedge Designation [Member] | Rate-Lock Mortgage Loan Commitments [Member]
Derivative financial instrument according to type of hedge [Abstract]
Notional Amount	$ 187,834			$ 168,816
Average Maturity	1 month 6 days			1 month 6 days
Fair Value	$ 3,198			$ 7,020
No Hedge Designation [Member] | Mandatory Commitments to Sell Mortgage Loans [Member]
Derivative financial instrument according to type of hedge [Abstract]
Notional Amount	$ 165,609			$ 186,092
Average Maturity	1 month 6 days			1 month 6 days
Fair Value	$ 896			$ (941)
No Hedge Designation [Member] | Interest-Rate Cap Agreements [Member]
Derivative financial instrument according to type of hedge [Abstract]
Notional Amount	$ 135,000			$ 135,000
Average Maturity	1 year 6 months			1 year 9 months 18 days
Fair Value	$ 20			$ 5
No Hedge Designation [Member] | Purchased Options [Member]
Derivative financial instrument according to type of hedge [Abstract]
Notional Amount	$ 2,193			$ 2,908
Average Maturity	4 months 24 days			6 months
Fair Value	$ 60			$ 42
No Hedge Designation [Member] | Written Options [Member]
Derivative financial instrument according to type of hedge [Abstract]
Notional Amount	$ 2,193			$ 2,848
Average Maturity	4 months 24 days			6 months
Fair Value	$ (60)			$ (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	$ 7,005			$ 7,088
Average Maturity	8 years 1 month 6 days			8 years 4 months 24 days
Fair Value	$ (423)			$ (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 7 months 6 days			7 years 1 month 6 days
Fair Value	$ 4,887			$ 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	$ 149,328			$ 147,456
Average Maturity	4 years 3 months 18 days			4 years 6 months
Fair Value	$ (6,425)			$ (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			$ 25,000
Average Maturity	3 months 18 days			7 months 6 days
Fair Value	$ (177)			$ (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	$ 149,328			$ 147,456
Average Maturity	4 years 3 months 18 days			4 years 6 months
Fair Value	$ 6,425			$ 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	3,198			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	896			0
Other Assets [Member] | No Hedge Designation [Member] | Interest-Rate Cap Agreements [Member]
Fair value of derivative instruments, balance sheet location [Abstract]
Asset Derivatives	20			5
Other Assets [Member] | No Hedge Designation [Member] | Purchased Options [Member]
Fair value of derivative instruments, balance sheet location [Abstract]
Asset Derivatives	60			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	4,887			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	140			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	6,565			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	423			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 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	60			42
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	6,565			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	177			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	$ 140			$ 0