Derivatives (Fair Values of Derivative Financial Instruments) (Details) - USD ($) $ in Thousands		Dec. 31, 2016	Dec. 31, 2015
Derivatives, Fair Value [Line Items]
Fair Values, Assets		$ 4,788	$ 224
Fair Values, Liabilities		26,846	21,034
Derivatives Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amounts		1,100,000	500,000
Fair Values, Liabilities	[1]	7,787	281
Derivatives Not Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amounts		1,242,791	1,002,350
Fair Values, Assets	[1]	20,315	23,251
Fair Values, Liabilities	[1]	19,645	23,687
Derivatives Not Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Notional Amounts	[2]	979,391	780,871
Fair Values, Assets	[1],[2]	18,405	20,622
Fair Values, Liabilities	[1],[2]	18,362	21,007
Derivatives Not Designated as Hedging Instruments [Member] | Risk Participation Agreements [Member]
Derivatives, Fair Value [Line Items]
Notional Amounts		84,732	83,430
Fair Values, Assets	[1]	50	83
Fair Values, Liabilities	[1]	105	162
Derivatives Not Designated as Hedging Instruments [Member] | Forward Commitments to Sell Residential Mortgage Loans [Member]
Derivatives, Fair Value [Line Items]
Notional Amounts		75,676	55,128
Fair Values, Assets	[1]	900	263
Fair Values, Liabilities	[1]	221	336
Derivatives Not Designated as Hedging Instruments [Member] | Interest Rate-Lock Commitments on Residential Mortgage Loans [Member]
Derivatives, Fair Value [Line Items]
Notional Amounts		46,840	38,853
Fair Values, Assets	[1]	189	243
Fair Values, Liabilities	[1]	228	167
Derivatives Not Designated as Hedging Instruments [Member] | Foreign Exchange Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Notional Amounts		56,152	44,068
Fair Values, Assets	[1]	771	2,040
Fair Values, Liabilities	[1]	729	2,015
Cash Flow Hedge [Member] | Derivatives Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Notional Amounts		1,100,000	500,000
Fair Values, Liabilities	[1]	$ 7,787	$ 281

[1] Derivative assets and liabilities are reported with other assets or other liabilities, respectively, in the consolidated balance sheets.

[2] The notional amount represents both the customer accommodation agreements and offsetting agreements with unrelated financial institutions