Derivative Financial Instruments (Schedule of Fair Value of Derivative Financial Instruments) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Derivative [Line Items]
Derivative Assets	$ 73,172	$ 52,069
Derivative Liabilities	68,088	35,671
Interest rate derivatives
Derivative [Line Items]
Derivative Assets	68,425	48,985
Derivative Liabilities	62,571	33,716
Designated as hedging instrument
Derivative [Line Items]
Derivative Assets	8,906	14,846
Derivative Liabilities	3,412	12
Not designed as hedging instrument
Derivative [Line Items]
Derivative Assets	64,266	37,223
Derivative Liabilities	64,676	35,659
Not designed as hedging instrument | Interest rate derivatives
Derivative [Line Items]
Derivative Assets	59,519	34,139
Derivative Liabilities	59,159	33,704
Not designed as hedging instrument | Interest rate lock commitments
Derivative [Line Items]
Derivative Assets	3,405	2,843
Derivative Liabilities	2,694	269
Not designed as hedging instrument | Forward commitments to sell mortgage loans
Derivative [Line Items]
Derivative Assets	0	14
Derivative Liabilities	1,486	1,457
Not designed as hedging instrument | Foreign currency derivatives
Derivative [Line Items]
Derivative Assets	1,342	227
Derivative Liabilities	1,337	229
Cash flow hedging | Designated as hedging instrument | Interest rate derivatives
Derivative [Line Items]
Derivative Assets	6,270	11,914
Derivative Liabilities	1,656	12
Fair value hedging | Designated as hedging instrument | Interest rate derivatives
Derivative [Line Items]
Derivative Assets	2,636	2,932
Derivative Liabilities	$ 1,756	$ 0