Basis of Presentation (Details Textual) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax	$ 3,499	$ 1,545	$ 8,566	$ 9,165
Other Tax Expense (Benefit)	1,225	$ 541	2,998	$ 3,208
Other Assets	321,475		321,475		$ 292,139
Assets, Total	10,691,077		10,691,077		10,056,972
Long-term debt	247,146		247,146		246,975
Liabilities, Total	9,246,993		9,246,993		8,792,311
Liabilities and Equity, Total	$ 10,691,077		$ 10,691,077		10,056,972
Effect of Change [Member]
Other Assets					(2,371)
Assets, Total					(2,371)
Long-term debt					(2,371)
Liabilities, Total					(2,371)
Liabilities and Equity, Total					$ (2,371)