Derivative Financial Instruments (Narrative) (Details)	12 Months Ended
	Dec. 31, 2016 USD ($) contracts derivative_instruments	Dec. 31, 2015 USD ($) derivative_instruments
Derivative Instruments, Gain (Loss) [Line Items]
Amount reclassified from accumulated other comprehensive income to interest expense	$ 5,000
Fair value of interest rate derivatives in a net liability position	14,100,000
Forward commitments to sell mortgage loans
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, notional amount	773,400,000	$ 753,900,000
Interest Rate Lock Commitments
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, notional amount	353,800,000
Foreign Exchange Contract
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, notional amount	$ 62,300,000
Call Options Written
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives, number of instruments held | derivative_instruments	0	0
Designated as hedging instrument | Cash flow hedging | Interest Rate Swap, $250 million, July 2019
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, notional amount	$ 250,000,000
Designated as hedging instrument | Cash flow hedging | Interest Rate Swap, $275 million, August 2019
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, notional amount	275,000,000
Designated as hedging instrument | Cash flow hedging | Interest Rate Cap $50 million Notional September 2017 Maturity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, notional amount	$ 50,000,000
Derivative, maturity date	Sep. 15, 2017
Designated as hedging instrument | Cash flow hedging | Interest Rate Cap $40 million Notional September 2017 Maturity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, notional amount	$ 40,000,000
Derivative, maturity date	Sep. 30, 2017
Designated as hedging instrument | Cash flow hedging | Interest rate swap | Cash flow hedge of variable rate deposits
Derivative Instruments, Gain (Loss) [Line Items]
Number of interest rate derivatives held | derivative_instruments	2
Designated as hedging instrument | Cash flow hedging | Interest rate swap | Interest Rate Swap, $250 million, July 2019
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, notional amount	$ 250,000,000
Designated as hedging instrument | Cash flow hedging | Interest rate swap | Interest Rate Swap, $275 million, August 2019
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, notional amount	$ 275,000,000
Designated as hedging instrument | Cash flow hedging | Interest rate cap | Cash flow hedge of junior subordinated debentures
Derivative Instruments, Gain (Loss) [Line Items]
Number of interest rate derivatives held | derivative_instruments	2
Derivative, notional amount	$ 90,000,000
Designated as hedging instrument | Cash flow hedging | Interest Rate Contract
Derivative Instruments, Gain (Loss) [Line Items]
Hedge ineffectiveness recognized	$ 0	$ 0
Designated as hedging instrument | Fair value hedging | Interest rate swap
Derivative Instruments, Gain (Loss) [Line Items]
Number of interest rate derivatives held | derivative_instruments	8
Derivative, notional amount	$ 82,100,000
Designated as hedging instrument | Fair value hedging | Interest Rate Contract
Derivative Instruments, Gain (Loss) [Line Items]
Fair value of derivatives, hedge ineffectiveness	$ 12,000	$ (16,000)
Not designed as hedging instrument | Interest rate cap
Derivative Instruments, Gain (Loss) [Line Items]
Number of interest rate derivatives held | contracts	1
Derivative, notional amount	$ 100,000,000
Not designed as hedging instrument | Interest Rate Contract
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, notional amount	$ 4,600,000,000
Not designed as hedging instrument | Interest Rate Contract | Minimum
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, maturity date	Jan. 31, 2017
Not designed as hedging instrument | Interest Rate Contract | Maximum
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, maturity date	Feb. 28, 2045