Income Taxes (Deferred Tax Assets and Deferred Tax Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Allowance for loan losses	$ 166,398	$ 192,534
Investments in qualified affordable housing partnerships, tax credit and other investments, net	14,977	11,174
Deferred compensation	23,954	23,604
Interest income on nonaccrual loans	4,192	5,909
State taxes	5,237	273
Unrealized losses on securities	37,423	0
Tax credit carryforwards	8,692	0
Premises and equipment	1,434	2,096
Lease liabilities	31,324	30,554
Other	1,018	1,441
Total deferred tax assets	294,649	267,585
Deferred tax liabilities:
Equipment lease financing	26,607	29,990
Investments in qualified affordable housing partnerships, tax credit and other investments, net	12,187	14,912
Core deposit intangibles	1,119	1,934
FHLB stock dividends	1,886	1,855
Mortgage servicing assets	1,759	1,675
Acquired debts	1,536	1,597
Prepaid expenses	1,525	1,194
Premises and equipment	0	99
Unrealized gains on securities	0	21,593
Operating lease right-of-use assets	29,472	28,468
Other	428	453
Total deferred tax liabilities	76,519	103,770
Net deferred tax assets	$ 218,130	$ 163,815