Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2016

Fair Value Disclosures [Abstract]

Assets and liabilities measured on recurring basis at fair value

The table below presents the Corporation’s investment securities available for sale and derivative financial instruments measured at fair value on a recurring basis as of December 31, 2016 and 2015, aggregated by the level in the fair value hierarchy within which those measurements fall.

Assets and Liabilities Measured at Fair Value on a Recurring Basis

	Fair Value Hierarchy	December 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	639,930		1,414,626
GNMA	Level 2	2,004,475		1,590,003
Private-label	Level 2	1,121		1,709
GNMA commercial mortgage-related securities	Level 2	2,028,898		1,955,310
Other securities (debt and equity)	Level 1	1,602		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	2,602		2,566
Total investment securities available for sale	Level 2	4,677,424		4,964,648
Total investment securities available for sale	Level 3	200		200
Interest rate-related instruments	Level 2	33,671		29,391
Foreign currency exchange forwards	Level 2	2,002		1,532
Interest rate lock commitments to originate residential mortgage loans held for sale	Level 3	206		958
Forward commitments to sell residential mortgage loans	Level 3	2,908		403
Commodity contracts	Level 2	16,725		1,269
Purchased options (time deposit)	Level 2	2,576		2,715
Liabilities:
Interest rate-related instruments	Level 2	$	33,188	$	30,886
Foreign currency exchange forwards	Level 2	1,943		1,398
Commodity contracts	Level 2	15,972		1,146
Written options (time deposit)	Level 2	2,576		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 years ended December 31, 2016 and 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 gains included in income:
Mortgage derivative gain	—		1,753
Balance December 31, 2016	$	200	$	3,114

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, 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
	Fair Value Hierarchy	Fair Value
	($ in Thousands)
December 31, 2016
Assets:
Commercial loans held for sale	Level 2	$	12,474	Provision for credit losses	$	(559	)
Mortgage loans held for sale	Level 2	108,010		Mortgage banking, net	(3,760		)
Impaired loans (1)	Level 3	79,270		Provision for credit losses	(75,194		)
Other real estate owned	Level 2	9,752		Foreclosure / OREO expense, net	(1,091		)
Mortgage servicing rights	Level 3	73,149		Mortgage banking, net	200
December 31, 2015
Assets:
Mortgage 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		)
Other real estate owned	Level 2	10,988		Foreclosure / OREO expense, net	(2,653		)
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.

Estimated fair values of financial instruments

Fair value estimates, methods, and assumptions are set forth below for the Corporation’s financial instruments.

		December 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	$	446,558	$	446,558	$	374,921	$	374,921
Interest-bearing deposits in other financial institutions	Level 1	149,175		149,175		79,764		79,764
Federal funds sold and securities purchased under agreements to resell	Level 1	46,500		46,500		19,000		19,000
Investment securities held to maturity	Level 2	1,273,536		1,264,674		1,168,230		1,184,442
Investment securities available for sale	Level 1	2,602		2,602		2,566		2,566
Investment securities available for sale	Level 2	4,677,424		4,677,424		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	140,001		140,001		147,240		147,240
Loans held for sale	Level 2	120,484		120,484		124,915		124,915
Loans, net	Level 3	19,776,381		19,680,317		18,440,079		18,389,832
Bank owned life insurance	Level 2	585,290		585,290		583,019		583,019
Derivatives (trading and other assets)	Level 2	54,974		54,974		34,907		34,907
Derivatives (trading and other assets)	Level 3	3,114		3,114		1,361		1,361
Financial liabilities:
Noninterest-bearing demand, savings, interest-bearing demand, and money market accounts	Level 3	$	20,282,321	$	20,282,321	$	19,444,863	$	19,444,863
Brokered CDs and other time deposits	Level 2	1,606,127		1,606,127		1,562,802		1,564,464
Short-term funding	Level 2	1,092,035		1,092,035		834,416		834,416
Long-term funding	Level 2	2,761,795		2,791,841		2,676,164		2,728,112
Standby letters of credit (1)	Level 2	2,566		2,566		2,954		2,954
Derivatives (trading and other liabilities)	Level 2	53,679		53,679		36,145		36,145

(1) The commitment on standby letters of credit was $260 million and $297 million at December 31, 2016 and 2015, respectively. See Note 16 for additional information on the standby letters of credit and for information on the fair value of lending-related commitments.