Investments in Qualified Affordable Housing Partnerships, Tax Credit and Other Investments, Net (Investments in Tax Credit and Other Investments, Net) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
INVESTMENTS IN QUALIFIED AFFORDABLE HOUSING PARTNERSHIPS, TAX CREDIT AND OTHER INVESTMENTS, NET
Minimum compliance period to fully utilize the tax credits	15 years
Investments in tax credit investments, net	$ 224,551	$ 173,280
Schedule of Equity Method Investments [Line Items]
Amortization of tax credit and other investments	87,950	83,446	$ 36,120
Accrued Expenses and Other Liabilities
Schedule of Equity Method Investments [Line Items]
Commitments for other tax credit investments	$ 113,400	$ 117,000