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 ($) $ in Thousands	3 Months Ended		60 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Investments in Tax Credit and Other Investments, Net [Line Items]
Investments in tax credit and other investments, net	$ 217,445		$ 231,635
Accrued expenses and other liabilities — Unfunded commitments	78,326		80,228
Amortization expense of tax credit and other investments	24,905	$ 17,400
Unrealized gains (losses) recognized on marketable equity securities held	392	$ (454)
Tax credit benefits			53,900
Pre-tax impairment charge	7,000
Impairment on tax credit investments
Investments in Tax Credit and Other Investments, Net [Line Items]
Marketable equity securities	$ 30,900		$ 31,200