Other Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Other Assets [Abstract]
Cash Surrender Value of Life Insurance	$ 195,163	$ 193,917
Interest and fees receivable income	78,822	82,935
Income Taxes Receivable	64,739	98,998
Equity Method Investments, Other Asset Investments	53,838	49,432
Low Income Housing Tax Credit - LIHTC	43,793	39,235
Equity Investments Without Readily Determinable Fair Value	15,642	14,856
Equity Investments With Readily Determinable Fair Value	5,028	0
Other Assets, Miscellaneous	54,159	61,350
Other Assets	$ 511,184	$ 540,723