Goodwill and Other Intangible Assets (Aggregate Amortization Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Aggregate amortization expense	$ 19,781	$ 24,184	$ 26,797
Core Deposit Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Aggregate amortization expense	16,411	18,031	19,897
Credit Card and Trust Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Aggregate amortization expense	2,172	2,369	2,566
Value of Insurance Business Acquired [Member]
Finite-Lived Intangible Assets [Line Items]
Aggregate amortization expense			34
Non-Compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Aggregate amortization expense			100
Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Aggregate amortization expense		2,388	2,605
Merchant Processing Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Aggregate amortization expense	$ 1,198	$ 1,396	$ 1,595