Derivative Financial Instruments (Schedule of Derivative Instruments in Statement of Financial Position, Fair Value) (Details) - USD ($) $ in Thousands		Dec. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Derivative Asset, Fair Value, Subject to a Master Netting Agreement		$ 35,727	$ 4,945
Derivative Asset, Total, Amount Offset		35,727	4,945
Derivative Asset, Fair Value, Less: Cash collateral posted		42,500	20,200
Derivative Asset	[1],[2]	0	0
Derivative Liability, Fair Value, Subject to a Master Netting Agreement		25,300	41,727
Derivative Liability, Fair Value, Less: Legally enforceable master netting agreements		24,854	36,275
Derivative Liability, Fair Value, Less: Cash collateral posted		18,700
Derivative Liability	[1],[2]	446	5,452
Mandatory forward commitments		99,000
Floating rate commitments		27,800
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Subject to a Master Netting Agreement		3,270	2,507
Derivative Asset, Total, Amount Offset		3,270	2,507
Derivative Asset	[1],[2]	0	0
Derivative Liability, Fair Value, Subject to a Master Netting Agreement		792	1,359
Derivative Liability, Fair Value, Less: Legally enforceable master netting agreements		792	1,359
Derivative Liability	[1],[2]	0	0
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Subject to a Master Netting Agreement		32,457	2,438
Derivative Asset, Total, Amount Offset		32,457	2,438
Derivative Asset	[1],[2]	0	0
Derivative Liability, Fair Value, Subject to a Master Netting Agreement		24,508	40,368
Derivative Liability, Fair Value, Less: Legally enforceable master netting agreements		24,062	34,916
Derivative Liability, Fair Value, Less: Cash collateral posted		10,900	31,300
Derivative Liability	[1],[2]	446	5,452
Derivatives Subject to Master Netting Arrangement or Similar Arrangement [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contract [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	[3]	225,000	200,000
Derivative Asset, Fair Value, Subject to a Master Netting Agreement	[3]	3,270	2,507
Derivative Liability, Notional Amount	[3]	100,000	100,000
Derivative Liability, Fair Value, Subject to a Master Netting Agreement	[3]	792	1,359
Derivatives Subject to Master Netting Arrangement or Similar Arrangement [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	[3]	1,943,485	989,695
Derivative Asset, Fair Value, Subject to a Master Netting Agreement	[3]	32,226	2,255
Derivative Liability, Notional Amount	[3]	1,242,937	1,543,479
Derivative Liability, Fair Value, Subject to a Master Netting Agreement	[3]	24,388	40,302
Derivatives Subject to Master Netting Arrangement or Similar Arrangement [Member] | Not Designated as Hedging Instrument [Member] | Other Contract [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	[3]	10,634	8,237
Derivative Asset, Fair Value, Subject to a Master Netting Agreement	[3]	231	183
Derivative Liability, Notional Amount	[3]	14,265	4,561
Derivative Liability, Fair Value, Subject to a Master Netting Agreement	[3]	120	66
Derivatives Not Subject to Master Netting Arrangement or Similar Arrangement [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	[4]	3,879,713	3,152,704
Derivative Asset, Fair Value, Not Subject to Master Netting Agreement	[4]	74,367	61,714
Derivative Liability, Notional Amount	[4]	2,856,313	2,123,823
Derivative Liability, Fair Value, Not Subject to Master Netting Agreement	[4]	44,397	41,193
Derivatives Not Subject to Master Netting Arrangement or Similar Arrangement [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	[4]	1,734,679	2,050,460
Derivative Asset, Fair Value, Not Subject to Master Netting Agreement	[4]	38,668	58,304
Derivative Liability, Notional Amount	[4]	1,451,762	482,738
Derivative Liability, Fair Value, Not Subject to Master Netting Agreement	[4]	19,001	571
Derivatives Not Subject to Master Netting Arrangement or Similar Arrangement [Member] | Not Designated as Hedging Instrument [Member] | Other Contract [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	[4]	1,438	0
Derivative Asset, Fair Value, Not Subject to Master Netting Agreement	[4]	19	0
Derivative Liability, Notional Amount	[4]	181	60
Derivative Liability, Fair Value, Not Subject to Master Netting Agreement	[4]	11	9
Derivatives Not Subject to Master Netting Arrangement or Similar Arrangement [Member] | Not Designated as Hedging Instrument [Member] | Credit Default Swap, Buying Protection [Member] | Credit Risk Contract [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	[4]	86,037	41,798
Derivative Asset, Fair Value, Not Subject to Master Netting Agreement	[4]	139	153
Derivatives Not Subject to Master Netting Arrangement or Similar Arrangement [Member] | Not Designated as Hedging Instrument [Member] | Credit Default Swap, Buying Protection [Member] | Mortgage Banking Derivatives [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	[4],[5]	103,440	62,514
Derivative Asset, Fair Value, Not Subject to Master Netting Agreement	[4],[5]	3,084	819
Derivatives Not Subject to Master Netting Arrangement or Similar Arrangement [Member] | Not Designated as Hedging Instrument [Member] | Credit Default Swap, Selling Protection [Member] | Credit Risk Contract [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	[4]	87,273	92,985
Derivative Liability, Fair Value, Not Subject to Master Netting Agreement	[4]	166	245
Derivatives Not Subject to Master Netting Arrangement or Similar Arrangement [Member] | Not Designated as Hedging Instrument [Member] | Credit Default Swap, Selling Protection [Member] | Mortgage Banking Derivatives [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	[4],[5]	59,895	0
Derivative Liability, Fair Value, Not Subject to Master Netting Agreement	[4],[5]	711	0
Subject to and not subject to Master Netting Agreements [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount		4,104,713	3,352,704
Derivative Asset, Fair Value, Gross derivative instruments, before netting		77,637	64,221
Derivative Asset, Total, Amount Offset		24,253	4,945
Derivative Asset, Fair Value, Less: Cash collateral posted		11,475	0
Derivative Asset		41,909	59,276
Derivative Liability, Notional Amount		2,956,313	2,223,823
Derivative Liability, Fair Value, Gross derivative instruments, before netting		45,189	42,552
Derivative Liability, Fair Value, Less: Legally enforceable master netting agreements		24,253	4,945
Derivative Liability, Fair Value, Less: Cash collateral posted		600	31,330
Derivative Liability		$ 20,336	$ 6,277

[1] Net amount excludes $42.5 million and $20.2 million of initial margin requirements posted at the derivative clearing organization at December 31, 2016 and December 31, 2015, respectively. Initial margin is recorded as a component of accrued interest receivable and other assets in the accompanying Consolidated Balance Sheets

[2] Net amount is net of $10.9 million and $31.3 million of cash collateral at December 31, 2016 and December 31, 2015, respectively, as presented in the accompanying Consolidated Balance Sheets.

[3] The Company has elected to report derivative positions subject to a legally enforceable master netting agreement on a net basis, net of cash collateral. Refer to the Offsetting Derivatives section of this footnote for additional information.

[4] Derivative positions not subject to a legally enforceable master netting agreement are reported on a gross basis in the accompanying Consolidated Balance Sheets.

[5] Notional amounts include mandatory forward commitments of $99.0 million, while notional amounts do not include approved floating rate commitments of $27.8 million, at December 31, 2016.