Fair Value Accounting and Measurement (Carrying Amounts and Estimated Fair Values of Selected Financial Instruments) (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Assets
Interest-earning deposits with banks	$ 54,124	$ 671,300
Debt securities available for sale at fair value	4,700,821	5,910,999
Debt Securities, Held-to-Maturity, Amortized Cost	2,079,285	2,148,327
Debt Securities, Held-to-maturity, Fair Value	1,747,282	2,122,606
Estimate of Fair Value Measurement [Member]
Assets
Cash and due from banks	263,551	153,414
Interest-earning deposits with banks	54,124	671,300
Debt securities available for sale at fair value	4,700,821	5,910,999
Debt Securities, Held-to-maturity, Fair Value	1,747,282	2,122,606
FHLB stock	10,560	10,280
Loans held for sale	1,251	9,774
Loans	11,353,412	10,679,349
Liabilities
Deposits	360,340	430,682
FHLB advances	14,290	8,752
Repurchase agreements	48,733	86,013
Subordinated Debentures	10,013	10,125
Junior subordinated debentures, fair value disclosure	9,984	9,927
Carrying Amount
Assets
Cash and due from banks	263,551	153,414
Interest-earning deposits with banks	54,124	671,300
Debt securities available for sale at fair value	4,700,821	5,910,999
Debt Securities, Held-to-Maturity, Amortized Cost	2,079,285	2,148,327
FHLB stock	10,560	10,280
Loans held for sale	1,251	9,774
Loans	11,537,390	10,486,359
Liabilities
Deposits	371,230	445,957
FHLB advances	14,322	7,359
Repurchase agreements	48,733	86,013
Subordinated Debentures	10,000	10,000
Junior subordinated debentures, fair value disclosure	10,310	10,310
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value Measurement [Member]
Assets
Cash and due from banks	263,551	153,414
Interest-earning deposits with banks	54,124	671,300
Debt securities available for sale at fair value	166,306	157,536
Debt Securities, Held-to-maturity, Fair Value	0	0
FHLB stock	0	0
Loans held for sale	0	0
Loans	0	0
Liabilities
Deposits	0	0
FHLB advances	0	0
Repurchase agreements	0	0
Subordinated Debentures	0	0
Junior subordinated debentures, fair value disclosure	0	0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value Measurement [Member]
Assets
Cash and due from banks	0	0
Interest-earning deposits with banks	0	0
Debt securities available for sale at fair value	4,534,515	5,753,463
Debt Securities, Held-to-maturity, Fair Value	1,747,282	2,122,606
FHLB stock	10,560	10,280
Loans held for sale	1,251	9,774
Loans	0	0
Liabilities
Deposits	360,340	430,682
FHLB advances	14,290	8,752
Repurchase agreements	48,733	86,013
Subordinated Debentures	10,013	10,125
Junior subordinated debentures, fair value disclosure	9,984	9,927
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value Measurement [Member]
Assets
Cash and due from banks	0	0
Interest-earning deposits with banks	0	0
Debt securities available for sale at fair value	0	0
Debt Securities, Held-to-maturity, Fair Value	0	0
FHLB stock	0	0
Loans held for sale	0	0
Loans	11,353,412	10,679,349
Liabilities
Deposits	0	0
FHLB advances	0	0
Repurchase agreements	0	0
Subordinated Debentures	0	0
Junior subordinated debentures, fair value disclosure	0	0
Interest Rate Swap Contracts | Estimate of Fair Value Measurement [Member]
Assets
Interest rate derivative asset	43,574	24,257
Liabilities
Interest rate derivative liability	43,574	24,257
Interest Rate Swap Contracts | Carrying Amount
Assets
Interest rate derivative asset	43,574	24,257
Liabilities
Interest rate derivative liability	43,574	24,257
Interest Rate Swap Contracts | Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value Measurement [Member]
Assets
Interest rate derivative asset	0	0
Liabilities
Interest rate derivative liability	0	0
Interest Rate Swap Contracts | Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value Measurement [Member]
Assets
Interest rate derivative asset	43,574	24,257
Liabilities
Interest rate derivative liability	43,574	24,257
Interest Rate Swap Contracts | Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value Measurement [Member]
Assets
Interest rate derivative asset	0	0
Liabilities
Interest rate derivative liability	0	0
Interest Rate Lock Commitments Contracts | Estimate of Fair Value Measurement [Member]
Assets
Interest rate derivative asset		356
Liabilities
Interest rate derivative liability	62
Interest Rate Lock Commitments Contracts | Carrying Amount
Assets
Interest rate derivative asset		356
Liabilities
Interest rate derivative liability	62
Interest Rate Lock Commitments Contracts | Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value Measurement [Member]
Assets
Interest rate derivative asset		0
Liabilities
Interest rate derivative liability	0
Interest Rate Lock Commitments Contracts | Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value Measurement [Member]
Assets
Interest rate derivative asset		0
Liabilities
Interest rate derivative liability	0
Interest Rate Lock Commitments Contracts | Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value Measurement [Member]
Assets
Interest rate derivative asset		356
Liabilities
Interest rate derivative liability	62
Interest rate Forward Sales Contracts | Estimate of Fair Value Measurement [Member]
Assets
Interest rate derivative asset	119
Liabilities
Interest rate derivative liability		27
Interest rate Forward Sales Contracts | Carrying Amount
Assets
Interest rate derivative asset	119
Liabilities
Interest rate derivative liability		27
Interest rate Forward Sales Contracts | Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value Measurement [Member]
Assets
Interest rate derivative asset	0
Liabilities
Interest rate derivative liability		0
Interest rate Forward Sales Contracts | Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value Measurement [Member]
Assets
Interest rate derivative asset	119
Liabilities
Interest rate derivative liability		27
Interest rate Forward Sales Contracts | Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value Measurement [Member]
Assets
Interest rate derivative asset	$ 0
Liabilities
Interest rate derivative liability		$ 0