Allowance for credit losses (Tables)

12 Months Ended

Dec. 31, 2016

Changes in the allowance for credit losses for the years ended December 31, 2016, 2015 and 2014 were as follows:

	Commercial, Financial,			Real Estate
2016	Leasing, etc.			Commercial			Residential			Consumer			Unallocated			Total
	(In thousands)
Beginning balance	$	300,404			326,831			72,238			178,320			78,199		$	955,992
Provision for credit losses		59,506			33,627			6,902			90,134			(169	)		190,000
Net charge-offs
Charge-offs		(59,244	)		(4,805	)		(26,133	)		(141,073	)		—			(231,255	)
Recoveries		30,167			7,066			8,120			28,907			—			74,260
Net (charge-offs) recoveries		(29,077	)		2,261			(18,013	)		(112,166	)		—			(156,995	)
Ending balance	$	330,833			362,719			61,127			156,288			78,030		$	988,997

	Commercial, Financial,			Real Estate
2015	Leasing, etc.			Commercial			Residential			Consumer			Unallocated		Total
	(In thousands)
Beginning balance	$	288,038			307,927			61,910			186,033			75,654	$	919,562
Provision for credit losses		43,065			25,768			19,133			79,489			2,545		170,000
Net charge-offs
Charge-offs		(60,983	)		(16,487	)		(13,116	)		(107,787	)		—		(198,373	)
Recoveries		30,284			9,623			4,311			20,585			—		64,803
Net charge-offs		(30,699	)		(6,864	)		(8,805	)		(87,202	)		—		(133,570	)
Ending balance	$	300,404			326,831			72,238			178,320			78,199	$	955,992

2014

Beginning balance	$	273,383			324,978			78,656			164,644			75,015	$	916,676
Provision for credit losses		51,410			(13,779	)		(3,974	)		89,704			639		124,000
Net charge-offs
Charge-offs		(58,943	)		(14,058	)		(21,351	)		(84,390	)		—		(178,742	)
Recoveries		22,188			10,786			8,579			16,075			—		57,628
Net charge-offs		(36,755	)		(3,272	)		(12,772	)		(68,315	)		—		(121,114	)
Ending balance	$	288,038			307,927			61,910			186,033			75,654	$	919,562

Impaired Loans and Leases

The following tables provide information with respect to loans and leases that were considered impaired as of December 31, 2016 and 2015 and for the years ended December 31, 2016, 2015 and 2014.

Interest Income Recognized on Impaired Loans

	Year Ended December 31, 2016						Year Ended December 31, 2015
			Interest Income Recognized						Interest Income Recognized
	Average Recorded Investment		Total		Cash Basis		Average Recorded Investment		Total		Cash Basis
	(In thousands)
Commercial, financial, leasing, etc.	$	277,647		8,342		8,342		236,201		2,933		2,933
Real estate:
Commercial		175,877		4,878		4,878		166,628		6,243		6,243
Residential builder and developer		29,237		2,300		2,300		59,457		335		335
Other commercial construction		19,697		644		644		20,276		2,311		2,311
Residential		98,394		6,227		3,154		101,483		6,188		4,037
Residential-limited documentation		103,060		5,999		1,975		118,449		6,380		2,638
Consumer:
Home equity lines and loans		36,493		1,325		410		21,523		905		261
Automobile		19,636		1,242		99		25,675		1,619		175
Other		9,218		440		83		18,809		729		113
Total	$	769,259		31,397		21,885		768,501		27,643		19,046

	Year Ended December 31, 2014
			Interest Income Recognized
	Average Recorded Investment		Total		Cash Basis
	(In thousands)
Commercial, financial, leasing, etc.	$	181,932		2,251		2,251
Real estate:
Commercial		184,773		4,029		4,029
Residential builder and developer		91,149		142		142
Other commercial construction		62,734		1,893		1,893
Residential		126,005		9,180		6,978
Residential-limited documentation		133,800		6,613		2,546
Consumer:
Home equity lines and loans		18,083		750		248
Automobile		35,173		2,251		295
Other		18,378		690		191
Total	$	852,027		27,799		18,573

Summary of Loan Grades

The following table summarizes the loan grades applied to the various classes of the Company’s commercial loans and commercial real estate loans.

			Real Estate
	Commercial,				Residential		Other
	Financial,				Builder and		Commercial
	Leasing, etc.		Commercial		Developer		Construction
	(In thousands)
December 31, 2016
Pass	$	21,398,581		24,570,269		1,789,071		5,912,351
Criticized accrual		950,032		741,274		116,548		165,862
Criticized nonaccrual		261,434		176,201		16,707		18,111
Total	$	22,610,047		25,487,744		1,922,326		6,096,324
December 31, 2015
Pass	$	19,442,183		22,697,398		1,497,465		3,834,137
Criticized accrual		738,238		655,257		59,779		228,877
Criticized nonaccrual		241,917		179,606		28,429		16,363
Total	$	20,422,338		23,532,261		1,585,673		4,079,377

Allocation of Allowance for Credit Losses on Basis of Company's Impairment Methodology

The allocation of the allowance for credit losses summarized on the basis of the Company’s impairment methodology was as follows:

	Commercial, Financial,		Real Estate
	Leasing, etc.		Commercial		Residential		Consumer		Total
	(In thousands)
December 31, 2016
Individually evaluated for impairment	$	48,480		12,500		9,457		12,543	$	82,980
Collectively evaluated for impairment		282,353		348,301		47,993		143,745		822,392
Purchased impaired		—		1,918		3,677		—		5,595
Allocated	$	330,833		362,719		61,127		156,288		910,967
Unallocated										78,030
Total									$	988,997
December 31, 2015
Individually evaluated for impairment	$	44,752		19,175		12,727		13,306	$	89,960
Collectively evaluated for impairment		255,615		307,000		57,624		163,511		783,750
Purchased impaired		37		656		1,887		1,503		4,083
Allocated	$	300,404		326,831		72,238		178,320		877,793
Unallocated										78,199
Total									$	955,992

Recorded Investment in Loans and Leases on Basis of Company's Impairment Methodology

The recorded investment in loans and leases summarized on the basis of the Company’s impairment methodology was as follows:

	Commercial, Financial,		Real Estate
	Leasing, etc.		Commercial		Residential		Consumer		Total
	(In thousands)
December 31, 2016
Individually evaluated for impairment	$	268,877		224,630		201,479		65,466	$	760,452
Collectively evaluated for impairment		22,340,529		33,222,080		21,871,726		12,080,597		89,514,932
Purchased impaired		641		59,684		517,707		—		578,032
Total	$	22,610,047		33,506,394		22,590,912		12,146,063	$	90,853,416
December 31, 2015
Individually evaluated for impairment	$	272,227		234,132		207,949		65,365	$	779,673
Collectively evaluated for impairment		20,148,209		28,863,130		25,398,037		11,532,121		85,941,497
Purchased impaired		1,902		100,049		664,117		2,261		768,329
Total	$	20,422,338		29,197,311		26,270,103		11,599,747	$	87,489,499