Fair Value (Tables)

9 Months Ended

Sep. 30, 2017

Fair Value [Abstract]

Financial Assets and Liabilities Measured at Fair Value on Recurring Basis

	September 30, 2017
(in thousands)	Level 1		Level 2		Level 3		Total
Assets
Available for sale debt securities:
U.S. Treasury and government agency securities	$	—	$	73,442	$	—	$	73,442
Municipal obligations		—		242,678		—		242,678
Corporate debt securities		—		3,500		—		3,500
Residential mortgage-backed securities		—		1,793,426		—		1,793,426
Commercial mortgage-backed securities		—		568,353		—		568,353
Collateralized mortgage obligations		—		173,879		—		173,879
Total available for sale securities		—		2,855,278		—		2,855,278
Derivative assets (1)		—		17,199		—		17,199
Total recurring fair value measurements - assets	$	—	$	2,872,477	$	—	$	2,872,477
Liabilities
Derivative liabilities (1)	$	—	$	12,691	$	—	$	12,691
Total recurring fair value measurements - liabilities	$	—	$	12,691	$	—	$	12,691

(1) For further disaggregation of derivative assets and liabilities, see Note 6 - Derivatives.

	December 31, 2016
(in thousands)	Level 1		Level 2		Level 3		Total
Assets
Available for sale debt securities:
U.S. Treasury and government agency securities	$	—	$	54,828	$	—	$	54,828
Municipal obligations		—		242,155		—		242,155
Corporate debt securities		—		3,500		—		3,500
Residential mortgage-backed securities		—		1,611,355		—		1,611,355
Commercial mortgage-backed securities		—		402,591		—		402,591
Collateralized mortgage obligations		—		202,479		—		202,479
Total available for sale securities		—		2,516,908		—		2,516,908
Derivative assets (1)		—		20,315		—		20,315
Total recurring fair value measurements - assets	$	—	$	2,537,223	$	—	$	2,537,223
Liabilities
Derivative liabilities (1)	$	—	$	27,432	$	—	$	27,432
Total recurring fair value measurements - liabilities	$	—	$	27,432	$	—	$	27,432

(1) For further disaggregation of derivative assets and liabilities, see Note 6 - Derivatives.

Financial Assets Measured at Fair Value on Nonrecurring Basis

	September 30, 2017
(in thousands)	Level 1		Level 2		Level 3		Total
Collateral-dependent impaired loans	$	—	$	129,230	$	—	$	129,230
Other real estate owned		—		—		6,810		6,810
Total nonrecurring fair value measurements	$	—	$	129,230	$	6,810	$	136,040

	December 31, 2016
(in thousands)	Level 1		Level 2		Level 3		Total
Collateral-dependent impaired loans	$	—	$	169,888	$	—	$	169,888
Other real estate owned		—		—		13,968		13,968
Total nonrecurring fair value measurements	$	—	$	169,888	$	13,968	$	183,856

Estimated Fair Values of Financial Instruments

	September 30, 2017
							Total Fair		Carrying
(in thousands)	Level 1		Level 2		Level 3		Value		Amount
Financial assets:
Cash, interest-bearing bank deposits, and federal funds sold	$	445,500	$	—	$	—	$	445,500	$	445,500
Available for sale securities		—		2,855,278		—		2,855,278		2,855,278
Held to maturity securities		—		2,768,148		—		2,768,148		2,769,274
Loans, net		—		129,230		18,300,747		18,429,977		18,563,163
Loans held for sale		—		23,236		—		23,236		23,236
Derivative financial instruments		—		17,199		—		17,199		17,199
Financial liabilities:
Deposits	$	—	$	—	$	21,523,649	$	21,523,649	$	21,533,859
Federal funds purchased		1,150		—		—		1,150		1,150
Securities sold under  agreements to repurchase		512,001		—		—		512,001		512,001
FHLB short-term borrowings		1,224,000		—		—		1,224,000		1,224,000
Long-term debt		—		330,909		—		330,909		331,179
Derivative financial instruments		—		12,691		—		12,691		12,691

	December 31, 2016
							Total Fair		Carrying
(in thousands)	Level 1		Level 2		Level 3		Value		Amount
Financial assets:
Cash, interest-bearing bank deposits, and federal funds sold	$	450,866	$	—	$	—	$	450,866	$	450,866
Available for sale securities		—		2,516,908		—		2,516,908		2,516,908
Held to maturity securities		—		2,470,117		—		2,470,117		2,500,220
Loans, net		—		169,888		16,326,961		16,496,849		16,522,733
Loans held for sale		—		34,064		—		34,064		34,064
Derivative financial instruments		—		20,315		—		20,315		20,315
Financial liabilities:
Deposits	$	—	$	—	$	19,430,939	$	19,430,939	$	19,424,266
Federal funds purchased		2,275		—		—		2,275		2,275
Securities sold under  agreements to repurchase		358,131		—		—		358,131		358,131
FHLB short-term borrowings		865,000		—		—		865,000		865,000
Long-term debt		—		435,747		—		435,747		436,280
Derivative financial instruments		—		27,432		—		27,432		27,432