Investments in Qualified Affordable Housing Partnerships, Tax Credit and Other Investments, Net and Variable Interest Entities (Investments in Tax Credit and Other Investments, Net) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Investments in Tax Credit and Other Investments, Net, And Related Unfunded Commitments [Abstract]
Investments in tax credit and other investments, net	$ 367,428,000		$ 367,428,000		$ 266,525,000
Accrued expenses and other liabilities — Unfunded commitments	194,796,000		194,796,000		105,282,000
Unrealized gains (losses) recognized on equity securities with readily determinable fair values	(88,000)	$ 55,000	(515,000)	$ 813,000
Adjustments to equity securities without readily determinable fair values	0	0	0	0
Asset impairment charges			4,843,000	0
Investment in tax credit and other investments
Investments in Tax Credit and Other Investments, Net, And Related Unfunded Commitments [Abstract]
Asset impairment charges	0	$ 0
Investment in Tax Credit and Other Investments, Multiple Credit
Investments in Tax Credit and Other Investments, Net, And Related Unfunded Commitments [Abstract]
Pre-tax recoveries			1,300,000	259,000
Investment in Tax Credit and Other Investments, OTTI, Single Credit
Investments in Tax Credit and Other Investments, Net, And Related Unfunded Commitments [Abstract]
Asset impairment charges				$ 733,000
Tax credit investments
Investments in Tax Credit and Other Investments, Net, And Related Unfunded Commitments [Abstract]
Equity securities with readily determinable fair values	26,800,000		26,800,000		31,300,000
Investments in Tax Credit and Other Investments and Other Assets
Investments in Tax Credit and Other Investments, Net, And Related Unfunded Commitments [Abstract]
Equity securities without readily determinable fair values	$ 29,300,000		$ 29,300,000		$ 23,700,000