Investments in Qualified Affordable Housing Partnerships, Tax Credit and Other Investments, Net (Investments in Qualified Affordable Housing Partnerships, Net) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Investments in Qualified Affordable Housing Partnerships, Tax Credit and Other Investments, Net [Abstract]
Minimum compliance period for qualified affordable housing partnerships to fully utilize the tax credits (in years)			15 years
Investments in qualified affordable housing partnerships, net	$ 148,097		$ 148,097		$ 162,824
Accrued expenses and other liabilities — Unfunded commitments	50,168		50,168		$ 55,815
Tax credits and other tax benefits recognized	9,425	$ 15,840	27,520	$ 35,027
Amortization expense included in income tax expense	$ 7,236	$ 8,944	$ 21,009	$ 22,945