Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2016

Fair Value Disclosures [Abstract]

Assets and Liabilities Measured on Recurring Basis at Fair Value

Assets and Liabilities Measured at Fair Value on a Recurring Basis

	Fair Value Hierarchy	March 31, 2016		December 31, 2015
		($ in Thousands)
Assets:
Investment securities available for sale:
U.S. Treasury securities	Level 1	$	1,000	$	997
Residential mortgage-related securities:
FNMA / FHLMC	Level 2	1,303,404		1,414,626
GNMA	Level 2	1,547,255		1,590,003
Private-label	Level 2	1,512		1,709
GNMA commercial mortgage-related securities	Level 2	2,047,865		1,955,310
Other securities (debt and equity)	Level 1	1,605		1,569
Other securities (debt and equity)	Level 2	3,000		3,000
Other securities (debt and equity)	Level 3	200		200
Total investment securities available for sale	Level 1	2,605		2,566
Total investment securities available for sale	Level 2	4,903,036		4,964,648
Total investment securities available for sale	Level 3	200		200
Interest rate-related instruments	Level 2	47,780		29,391
Foreign currency exchange forwards	Level 2	4,203		1,532
Interest rate lock commitments to originate residential mortgage loans held for sale	Level 3	2,689		958
Forward commitments to sell residential mortgage loans	Level 3	—		403
Commodity contracts	Level 2	1,104		1,269
Purchased options (time deposit)	Level 2	2,228		2,715
Liabilities:
Interest rate-related instruments	Level 2	50,145		30,886
Foreign currency exchange forwards	Level 2	4,097		1,398
Forward commitments to sell residential mortgage loans	Level 3	1,732		—
Commodity contracts	Level 2	981		1,146
Written options (time deposit)	Level 2	2,228		2,715

Assets and Liabilities Measured at Fair Value Using Significant Unobservable Inputs (Level 3)

The table below presents a rollforward of the balance sheet amounts for the three months ended March 31, 2016 and the year ended December 31, 2015, for financial instruments measured on a recurring basis and classified within Level 3 of the fair value hierarchy.

	Investment Securities Available for Sale		Derivative Financial Instruments
	($ in Thousands)
Balance December 31, 2014	$	200	$	(488	)
Total net gains included in income:
Mortgage derivative gain	—		1,849
Balance December 31, 2015	$	200	$	1,361
Total net losses included in income:
Mortgage derivative loss	—		(404		)
Balance March 31, 2016	$	200	$	957

Assets and Liabilities Measured on Nonrecurring Basis at Fair Value

The table below presents the Corporation’s loans held for sale, impaired loans, and mortgage servicing rights measured at fair value on a nonrecurring basis as of March 31, 2016 and December 31, 2015, aggregated by the level in the fair value hierarchy within which those measurements fall.

Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis

				Income Statement Category of Adjustment Recognized in Income	Adjustment Recognized in Income
($ in Thousands)	Fair Value Hierarchy	Fair Value
March 31, 2016
Assets:
Loans held for sale (2)	Level 2	$	129,398	Mortgage banking, net	$	—
Impaired loans (1)	Level 3	84,664		Provision for credit losses	(15,097		)
Mortgage servicing rights	Level 3	61,410		Mortgage banking, net	(909		)
December 31, 2015
Assets:
Loans held for sale	Level 2	$	124,915	Mortgage banking, net	$	(155	)
Impaired loans (1)	Level 3	41,891		Provision for credit losses	(7,796		)
Mortgage servicing rights	Level 3	70,686		Mortgage banking, net	425

(1) Represents individually evaluated impaired loans, net of the related allowance for loan losses.

(2) Loans held for sale are carried at the lower of cost or estimated fair value. At March 31, 2016, the estimated fair value exceeded the cost and therefore there was no adjustment recognized in Income.

Estimated fair values of financial instruments

The estimated fair values of the Corporation’s financial instruments were as follows.

		March 31, 2016				December 31, 2015
	Fair Value Hierarchy Level	Carrying Amount		Fair Value		Carrying Amount		Fair Value
		($ in Thousands)
Financial assets:
Cash and due from banks	Level 1	$	287,183	$	287,183	$	374,921	$	374,921
Interest-bearing deposits in other financial institutions	Level 1	68,025		68,025		79,764		79,764
Federal funds sold and securities purchased under agreements to resell	Level 1	20,200		20,200		19,000		19,000
Investment securities held to maturity	Level 2	1,176,821		1,204,345		1,168,230		1,184,442
Investment securities available for sale	Level 1	2,605		2,605		2,566		2,566
Investment securities available for sale	Level 2	4,903,036		4,903,036		4,964,648		4,964,648
Investment securities available for sale	Level 3	200		200		200		200
FHLB and Federal Reserve Bank stocks	Level 2	181,853		181,853		147,240		147,240
Loans held for sale	Level 2	128,339		129,398		124,915		124,915
Loans, net	Level 3	18,949,870		19,025,680		18,440,079		18,389,832
Bank owned life insurance	Level 2	580,583		580,583		583,019		583,019
Derivatives (trading and other assets)	Level 2	55,315		55,315		34,907		34,907
Derivatives (trading and other assets)	Level 3	2,689		2,689		1,361		1,361
Financial liabilities:
Noninterest-bearing demand, savings, interest-bearing demand, and money market accounts	Level 3	$	19,117,418	$	19,117,418	$	19,444,863	$	19,444,863
Brokered CDs and other time deposits	Level 2	1,568,042		1,576,714		1,562,802		1,564,464
Short-term funding	Level 2	1,417,408		1,417,408		834,416		834,416
Long-term funding	Level 2	2,861,316		2,925,447		2,676,164		2,728,112
Standby letters of credit (1)	Level 2	2,746		2,746		2,954		2,954
Derivatives (trading and other liabilities)	Level 2	57,451		57,451		36,145		36,145
Derivatives (trading and other liabilities)	Level 3	1,732		1,732		—		—