M&T Bank (MTB) 10-Q 5 Aug 15 2015 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2015	Jul. 24, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q2
Trading Symbol	MTB
Entity Registrant Name	M&T BANK CORP
Entity Central Index Key	36,270
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		133,238,280

Consolidated Balance Sheet (Una

Consolidated Balance Sheet (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Assets
Cash and due from banks	$ 1,347,858	$ 1,289,965
Interest-bearing deposits at banks	4,045,852	6,470,867
Federal funds sold	3,000	83,392
Trading account	277,009	308,175
Investment securities (includes pledged securities that can be sold or repledged of $1,615,114 at June 30, 2015; $1,631,267 at December 31, 2014)
Available for sale (cost: $11,093,093 at June 30, 2015; $8,919,324 at December 31, 2014)	11,250,877	9,156,932
Held to maturity (fair value: $3,175,847 at June 30, 2015; $3,538,282 at December 31, 2014)	3,164,585	3,507,868
Other (fair value: $336,175 at June 30, 2015; $328,742 at December 31, 2014)	336,175	328,742
Total investment securities	14,751,637	12,993,542
Loans and leases	68,358,516	66,899,369
Unearned discount	(227,264)	(230,413)
Loans and leases, net of unearned discount	68,131,252	66,668,956
Allowance for credit losses	(929,987)	(919,562)
Loans and leases, net	67,201,265	65,749,394
Premises and equipment	590,567	612,984
Goodwill	3,513,325	3,524,625
Core deposit and other intangible assets	22,269	35,027
Accrued interest and other assets	5,327,294	5,617,564
Total assets	97,080,076	96,685,535
Liabilities
Noninterest-bearing deposits	27,674,588	26,947,880
NOW accounts	2,579,307	2,307,815
Savings deposits	39,306,647	41,085,803
Time deposits	2,901,636	3,063,973
Deposits at Cayman Islands office	167,441	176,582
Total deposits	72,629,619	73,582,053
Federal funds purchased and agreements to repurchase securities	153,299	192,676
Accrued interest and other liabilities	1,453,249	1,567,951
Long-term borrowings	10,175,912	9,006,959
Total liabilities	84,412,079	84,349,639
Shareholders' equity
Preferred stock, $1.00 par, 1,000,000 shares authorized; Issued and outstanding: Liquidation preference of $1,000 per share: 731,500 shares at June 30, 2015 and December 31, 2014; Liquidation preference of $10,000 per share: 50,000 shares at June 30, 2015 and December 31, 2014	1,231,500	1,231,500
Common stock, $.50 par, 250,000,000 shares authorized, 133,062,420 shares issued at June 30, 2015; 132,312,931 shares issued at December 31, 2014	66,531	66,157
Common stock issuable, 36,511 shares at June 30, 2015; 41,330 shares at December 31, 2014	2,332	2,608
Additional paid-in capital	3,477,611	3,409,506
Retained earnings	8,107,525	7,807,119
Accumulated other comprehensive income (loss), net	(217,502)	(180,994)
Total shareholders' equity	12,667,997	12,335,896
Total liabilities and shareholders' equity	$ 97,080,076	$ 96,685,535

Consolidated Balance Sheet (Un3

Consolidated Balance Sheet (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Pledged securities that can be sold or repledged	$ 1,615,114	$ 1,631,267
Investment securities, available for sale, amortized cost	11,093,093	8,919,324
Investment securities, held to maturity, fair value	3,175,847	3,538,282
Other, fair value	$ 336,175	$ 328,742
Preferred stock, par value	$ 1	$ 1
Preferred stock, shares authorized	1,000,000	1,000,000
Common stock, par value	$ 0.50	$ 0.50
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	133,062,420	132,312,931
Common stock issuable, shares	36,511	41,330
Series A and Series C [Member]
Preferred stock, shares issued	731,500	731,500
Preferred stock, shares outstanding	731,500	731,500
Preferred stock, liquidation preference per share	$ 1,000	$ 1,000
Series D Preferred Stock [Member]
Preferred stock, shares issued	50,000	50,000
Preferred stock, shares outstanding	50,000	50,000
Preferred stock, liquidation preference per share	$ 10,000	$ 10,000

Consolidated Statement of Incom

Consolidated Statement of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Interest income
Loans and leases, including fees	$ 662,633	$ 645,029	$ 1,309,812	$ 1,290,251
Investment securities
Fully taxable	93,144	85,210	179,101	159,109
Exempt from federal taxes	1,062	1,293	2,380	2,797
Deposits at banks	3,351	2,535	6,469	4,419
Other	164	223	679	666
Total interest income	760,354	734,290	1,498,441	1,457,242
Interest expense
NOW accounts	349	330	660	627
Savings deposits	10,361	11,181	20,580	22,782
Time deposits	3,690	3,855	7,430	7,795
Deposits at Cayman Islands office	150	181	297	389
Short-term borrowings	36	25	70	57
Long-term borrowings	62,640	49,604	126,688	100,045
Total interest expense	77,226	65,176	155,725	131,695
Net interest income	683,128	669,114	1,342,716	1,325,547
Provision for credit losses	30,000	30,000	68,000	62,000
Net interest income after provision for credit losses	653,128	639,114	1,274,716	1,263,547
Other income
Mortgage banking revenues	102,602	95,656	204,203	175,705
Service charges on deposit accounts	105,257	107,368	207,601	211,566
Trust income	118,598	129,893	242,332	251,145
Brokerage services income	16,861	17,487	32,322	33,987
Trading account and foreign exchange gains	6,046	8,042	12,277	14,489
Loss on bank investment securities	(10)		(108)
Equity in earnings of Bayview Lending Group LLC	(3,131)	(4,055)	(7,322)	(8,509)
Other revenues from operations	150,804	102,021	245,925	198,136
Total other income	497,027	456,412	937,230	876,519
Other expense
Salaries and employee benefits	361,657	339,713	751,550	711,039
Equipment and net occupancy	66,852	68,084	133,322	139,251
Printing, postage and supplies	9,305	9,180	18,895	20,136
Amortization of core deposit and other intangible assets	5,965	9,234	12,758	19,296
FDIC assessments	10,801	15,155	21,461	30,643
Other costs of operations	242,048	226,294	445,017	437,529
Total other expense	696,628	667,660	1,383,003	1,357,894
Income before taxes	453,527	427,866	828,943	782,172
Income taxes	166,839	143,530	300,642	268,819
Net income	286,688	284,336	528,301	513,353
Net income available to common shareholders
Basic	263,471	260,680	482,295	472,404
Diluted	$ 263,481	$ 260,695	$ 482,313	$ 472,429
Net income per common share
Basic	$ 1.99	$ 1.99	$ 3.65	$ 3.62
Diluted	1.98	1.98	3.63	3.59
Cash dividends per common share	$ 0.70	$ 0.70	$ 1.40	$ 1.40
Average common shares outstanding
Basic	132,356	130,856	132,203	130,536
Diluted	133,116	131,828	132,944	131,479

Consolidated Statement of Compr

Consolidated Statement of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement of Partners' Capital [Abstract]
Net income	$ 286,688	$ 284,336	$ 528,301	$ 513,353
Other comprehensive income (loss), net of tax and reclassification adjustments:
Net unrealized gains (losses) on investment securities	(72,618)	64,652	(47,279)	102,866
Unrealized gains (losses) on cash flow hedges	(24)	(711)	847	(711)
Foreign currency translation adjustment	1,866	449	(518)	313
Defined benefit plans liability adjustment	5,765	1,179	10,442	1,999
Total other comprehensive income (loss)	(65,011)	65,569	(36,508)	104,467
Total comprehensive income	$ 221,677	$ 349,905	$ 491,793	$ 617,820

Consolidated Statement of Cash

Consolidated Statement of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Cash flows from operating activities
Net income	$ 528,301	$ 513,353
Adjustments to reconcile net income to net cash provided by operating activities
Provision for credit losses	68,000	62,000
Depreciation and amortization of premises and equipment	48,199	49,133
Amortization of capitalized servicing rights	24,572	34,868
Amortization of core deposit and other intangible assets	12,758	19,296
Provision for deferred income taxes	29,884	40,964
Asset write-downs	4,076	2,015
Net gain on sales of assets	(48,637)	(1,991)
Net change in accrued interest receivable, payable	7,912	10,036
Net change in other accrued income and expense	(39,503)	(82,817)
Net change in loans originated for sale	(77,677)	(192,521)
Net change in trading account assets and liabilities	198	15,168
Net cash provided by operating activities	558,083	469,504
Cash flows from investing activities
Proceeds from sales of investment securities Available for sale	2,539	16
Proceeds from sales of investment securities Other	254	734
Proceeds from maturities of investment securities Available for sale	859,904	375,372
Proceeds from maturities of investment securities Held to maturity	351,110	211,005
Purchases of investment securities Available for sale	(3,013,384)	(3,609,758)
Purchases of investment securities Held to maturity	(17,403)	(10,745)
Purchases of investment securities Other	(7,686)	(52,904)
Net increase in loans and leases	(1,465,261)	(566,803)
Net (increase) decrease in interest-bearing deposits at banks	2,425,015	(1,381,392)
Capital expenditures, net	(23,395)	(37,747)
Net (increase) decrease in loan servicing advances	317,276	(257,704)
Other, net	16,450	16,990
Net cash used by investing activities	(554,581)	(5,312,936)
Cash flows from financing activities
Net increase (decrease) in deposits	(951,347)	2,712,470
Net decrease in short-term borrowings	(39,377)	(98,824)
Proceeds from long-term borrowings	1,500,000	2,647,688
Payments on long-term borrowings	(323,025)	(360,345)
Proceeds from issuance of preferred stock		346,500
Dividends paid - common	(187,278)	(185,134)
Dividends paid - preferred	(40,635)	(29,348)
Other, net	15,661	54,927
Net cash provided (used) by financing activities	(26,001)	5,087,934
Net increase (decrease) in cash and cash equivalents	(22,499)	244,502
Cash and cash equivalents at beginning of period	1,373,357	1,672,934
Cash and cash equivalents at end of period	1,350,858	1,917,436
Supplemental disclosure of cash flow information
Interest received during the period	1,478,848	1,420,720
Interest paid during the period	149,255	120,109
Income taxes paid during the period	225,107	198,028
Supplemental schedule of noncash investing and financing activities
Securitization of residential mortgage loans allocated to Available-for-sale investment securities	36,645	76,097
Securitization of residential mortgage loans allocated to capitalized servicing rights	368	976
Real estate acquired in settlement of loans	$ 23,273	$ 18,677

Consolidated Statement of Chang

Consolidated Statement of Changes in Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Series E Preferred Stock [Member]	Preferred Stock [Member]	Preferred Stock [Member]Series E Preferred Stock [Member]	Common Stock [Member]	Common Stock [Member]Series A Warrants [Member]	Common Stock Issuable [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member]Series A Warrants [Member]	Additional Paid-in Capital [Member]Series E Preferred Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss), Net [Member]
Beginning balance at Dec. 31, 2013	$ 11,305,532		$ 881,500		$ 65,258		$ 2,915	$ 3,232,014			$ 7,188,004	$ (64,159)
Total comprehensive income	617,820										513,353	104,467
Preferred stock cash dividends	(35,117)										(35,117)
Exercise of stock warrants into common stock						$ 75			$ (75)
Issuance of Series E preferred stock		$ 346,500		$ 350,000						$ (3,500)
Stock-based compensation plans:
Compensation expense, net	23,381				131			23,250
Exercises of stock options, net	84,444				442			84,002
Stock purchase plan	9,588				43			9,545
Directors' stock plan	879				4			875
Deferred compensation plans, net, including dividend equivalents	(61)				3		(315)	309			(58)
Other	894							894
Common stock cash dividends - $1.40 per share	(185,105)										(185,105)
Ending balance at Jun. 30, 2014	12,168,755		1,231,500		65,956		2,600	3,347,314			7,481,077	40,308
Beginning balance at Dec. 31, 2014	12,335,896		1,231,500		66,157		2,608	3,409,506			7,807,119	(180,994)
Total comprehensive income	491,793										528,301	(36,508)
Preferred stock cash dividends	(40,635)										(40,635)
Exercise of stock warrants into common stock						$ 1			$ (1)
Stock-based compensation plans:
Compensation expense, net	21,110				144			20,966
Exercises of stock options, net	35,116				179			34,937
Stock purchase plan	10,346				45			10,301
Directors' stock plan	830				3			827
Deferred compensation plans, net, including dividend equivalents	(51)				2		(276)	274			(51)
Other	801							801
Common stock cash dividends - $1.40 per share	(187,209)										(187,209)
Ending balance at Jun. 30, 2015	$ 12,667,997		$ 1,231,500		$ 66,531		$ 2,332	$ 3,477,611			$ 8,107,525	$ (217,502)

Consolidated Statement of Chan8

Consolidated Statement of Changes in Shareholders' Equity (Unaudited) (Parenthetical) - $ / shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Common stock per share dividend amount	$ 0.70	$ 0.70	$ 1.40	$ 1.40
Common Stock [Member] | Series A Warrants [Member]
Exercise of warrants into shares of common stock	2,315	379,376	2,315	379,376
Exercise of warrants into shares of common stock			904	149,834
Retained Earnings [Member]
Common stock per share dividend amount			$ 1.40	$ 1.40

Significant accounting policies

Significant accounting policies	6 Months Ended
	Jun. 30, 2015
Accounting Policies [Abstract]
Significant accounting policies	1. Significant accounting policies The consolidated financial statements of M&T Bank Corporation (“M&T”) and subsidiaries (“the Company”) were compiled in accordance with generally accepted accounting principles (“GAAP”) using the accounting policies set forth in note 1 of Notes to Financial Statements included in the 2014 Annual Report. Additionally, effective January 1, 2015 the Company made an accounting policy election in accordance with amended accounting guidance issued by the Financial Accounting Standards Board in January 2014 to account for investments in qualified affordable housing projects using the proportional amortization method. Under the proportional amortization method, the Company amortizes the initial cost of the investment in proportion to the tax credits and other tax benefits received and recognizes the net investment performance in the income statement as a component of income tax expense. The adoption of the amended guidance did not have a significant effect on the Company’s financial position or results of operations, but did result in the restatement of the consolidated statement of income for the three months and six months ended June 30, 2014 to remove $14 million and $26 million, respectively, of losses associated with qualified affordable housing projects from “other costs of operations” and include the amortization of the initial cost of the investment in income tax expense. The cumulative effect adjustment associated with adopting the amended guidance was not material as of the beginning of any period presented in these consolidated financial statements. See note 11 for information regarding the Company’s investments in qualified affordable housing projects. In the opinion of management, all adjustments necessary for a fair presentation have been made and, except as described above, were all of a normal recurring nature.

Acquisitions

Acquisitions	6 Months Ended
	Jun. 30, 2015
Business Combinations [Abstract]
Acquisitions	2. Acquisitions On August 27, 2012, M&T announced that it had entered into a definitive agreement with Hudson City Bancorp, Inc. (“Hudson City”), headquartered in Paramus, New Jersey, under which Hudson City would be acquired by M&T. Pursuant to the terms of the agreement, Hudson City shareholders will receive consideration for each common share of Hudson City in an amount valued at .08403 of an M&T share in the form of either M&T common stock or cash, based on the election of each Hudson City shareholder, subject to proration as specified in the merger agreement (which provides for an aggregate split of total consideration of 60% common stock of M&T and 40% cash). As of June 30 , At June 30, 2015, Hudson City had $35.4 billion of assets, including $19.9 billion of loans and $8.1 billion of investment securities, and $30.6 billion of liabilities, including $18.2 billion of deposits. The merger has received the approval of the common shareholders of M&T and Hudson City. However, the merger is subject to a number of other conditions, including regulatory approvals. On June 17, 2013, M&T and Manufacturers and Traders Trust Company (“M&T Bank”), M&T’s principal banking subsidiary, entered into a written agreement with the Federal Reserve Bank of New York (“Federal Reserve Bank”). Under the terms of the agreement, M&T and M&T Bank are required to submit to the Federal Reserve Bank a revised compliance risk management program designed to ensure compliance with the Bank Secrecy Act and anti-money-laundering laws and regulations and to take certain other steps to enhance their compliance practices. The Company commenced a major initiative, including the hiring of outside consulting firms, intended to fully address the Federal Reserve Bank’s concerns. On April 3, 2015, M&T was advised that the Federal Reserve Board intends to act on the M&T and Hudson City merger application no later than September 30, 2015. As a result, M&T and Hudson City extended the date after which either party may elect to terminate the merger agreement if the merger has not yet been completed from April 30, 2015 to October 31, 2015. Nevertheless, there can be no assurances that the merger will be completed by that date. NOTES TO FINANCIAL STATEMENTS, CONTINUED

Investment securities

Investment securities	6 Months Ended
	Jun. 30, 2015
Investments, Debt and Equity Securities [Abstract]
Investment securities	3. Investment securities The amortized cost and estimated fair value of investment securities were as follows: Amortized Gross Gross Estimated (in thousands) June 30, 2015 Investment securities available for sale: U.S. Treasury and federal agencies $ 197,315 1,404 1 $ 198,718 Obligations of states and political subdivisions 7,387 169 52 7,504 Mortgage-backed securities: Government issued or guaranteed 10,637,736 174,277 40,121 10,771,892 Privately issued 89 2 3 88 Collateralized debt obligations 28,381 22,518 416 50,483 Other debt securities 138,525 1,672 18,243 121,954 Equity securities 83,660 16,777 199 100,238 11,093,093 216,819 59,035 11,250,877 Investment securities held to maturity: Obligations of states and political subdivisions 136,922 1,584 391 138,115 Mortgage-backed securities: Government issued or guaranteed 2,828,638 54,355 10,143 2,872,850 Privately issued 191,910 1,868 36,011 157,767 Other debt securities 7,115 — — 7,115 3,164,585 57,807 46,545 3,175,847 Other securities 336,175 — — 336,175 Total $ 14,593,853 274,626 105,580 $ 14,762,899 December 31, 2014 Investment securities available for sale: U.S. Treasury and federal agencies $ 161,408 544 5 $ 161,947 Obligations of states and political subdivisions 8,027 224 53 8,198 Mortgage-backed securities: Government issued or guaranteed 8,507,571 223,889 337 8,731,123 Privately issued 104 2 3 103 Collateralized debt obligations 30,073 21,276 1,033 50,316 Other debt securities 138,240 1,896 18,648 121,488 Equity securities 73,901 11,020 1,164 83,757 8,919,324 258,851 21,243 9,156,932 Investment securities held to maturity: Obligations of states and political subdivisions 148,961 2,551 189 151,323 Mortgage-backed securities: Government issued or guaranteed 3,149,320 78,485 7,000 3,220,805 Privately issued 201,733 1,143 44,576 158,300 Other debt securities 7,854 — — 7,854 3,507,868 82,179 51,765 3,538,282 Other securities 328,742 — — 328,742 Total $ 12,755,934 341,030 73,008 $ 13,023,956 There were no significant gross realized gains or losses from the sale of investment securities for the three-month and six-month periods ended June 30, 2015 and 2014, respectively. At June 30, 2015, the amortized cost and estimated fair value of debt securities by contractual maturity were as follows: Amortized Estimated (in thousands) Debt securities available for sale: Due in one year or less $ 10,418 10,461 Due after one year through five years 197,809 199,557 Due after five years through ten years 2,619 2,637 Due after ten years 160,762 166,004 371,608 378,659 Mortgage-backed securities available for sale 10,637,825 10,771,980 $ 11,009,433 11,150,639 Debt securities held to maturity: Due in one year or less $ 28,570 28,738 Due after one year through five years 83,513 84,258 Due after five years through ten years 24,839 25,119 Due after ten years 7,115 7,115 144,037 145,230 Mortgage-backed securities held to maturity 3,020,548 3,030,617 $ 3,164,585 3,175,847 A summary of investment securities that as of June 30, 2015 and December 31, 2014 had been in a continuous unrealized loss position for less than twelve months and those that had been in a continuous unrealized loss position for twelve months or longer follows: Less than 12 months 12 months or more Fair value Unrealized Fair value Unrealized (in thousands) June 30, 2015 Investment securities available for sale: U.S. Treasury and federal agencies $ 1,750 (1 ) — — Obligations of states and political subdivisions 1,403 (7 ) 1,527 (45 ) Mortgage-backed securities: Government issued or guaranteed 2,688,635 (39,970 ) 6,231 (151 ) Privately issued 15 — 53 (3 ) Collateralized debt obligations — — 2,444 (416 ) Other debt securities 13,142 (185 ) 93,061 (18,058 ) Equity securities — — 226 (199 ) 2,704,945 (40,163 ) 103,542 (18,872 ) Investment securities held to maturity: Obligations of states and political subdivisions 38,431 (360 ) 2,289 (31 ) Mortgage-backed securities: Government issued or guaranteed 383,167 (2,693 ) 249,870 (7,450 ) Privately issued — — 127,482 (36,011 ) 421,598 (3,053 ) 379,641 (43,492 ) Total $ 3,126,543 (43,216 ) 483,183 (62,364 ) December 31, 2014 Investment securities available for sale: U.S. Treasury and federal agencies $ 6,505 (5 ) — — Obligations of states and political subdivisions 1,785 (52 ) 121 (1 ) Mortgage-backed securities: Government issued or guaranteed 39,001 (186 ) 5,555 (151 ) Privately issued — — 65 (3 ) Collateralized debt obligations 2,108 (696 ) 5,512 (337 ) Other debt securities 14,017 (556 ) 92,661 (18,092 ) Equity securities 2,138 (1,164 ) — — 65,554 (2,659 ) 103,914 (18,584 ) Investment securities held to maturity: Obligations of states and political subdivisions 29,886 (184 ) 268 (5 ) Mortgage-backed securities: Government issued or guaranteed 137,413 (361 ) 446,780 (6,639 ) Privately issued — — 127,512 (44,576 ) 167,299 (545 ) 574,560 (51,220 ) Total $ 232,853 (3,204 ) 678,474 (69,804 ) The Company owned 383 individual investment securities with aggregate gross unrealized losses of $106 million at June 30, 2015. Based on a review of each of the securities in the investment securities portfolio at June 30, 2015, the Company concluded that it expected to recover the amortized cost basis of its investment. As of June 30, 2015, the Company does not intend to sell nor is it anticipated that it would be required to sell any of its impaired investment securities at a loss. At June 30, 2015, the Company has not identified events or changes in circumstances which may have a significant adverse effect on the fair value of the $336 million of cost method investment securities.

Loans and leases and the allowa

Loans and leases and the allowance for credit losses	6 Months Ended
	Jun. 30, 2015
Receivables [Abstract]
Loans and leases and the allowance for credit losses	4. Loans and leases and the allowance for credit losses The outstanding principal balance and the carrying amount of acquired loans that were recorded at fair value at the acquisition date and included in the consolidated balance sheet follow: June 30, December 31, (in thousands) Outstanding principal balance $ 2,631,165 3,070,268 Carrying amount: Commercial, financial, leasing, etc. 191,721 247,820 Commercial real estate 775,816 961,828 Residential real estate 407,774 453,360 Consumer 844,068 933,537 $ 2,219,379 2,596,545 Purchased impaired loans included in the table above totaled $169 million at June 30, 2015 and $198 million at December 31, 2014, representing less than 1% of the Company’s assets as of each date. A summary of changes in the accretable yield for acquired loans for the three months and six months ended June 30, 2015 and 2014 follows: Three months ended June 30 2015 2014 Purchased Other Purchased Other (in thousands) Balance at beginning of period $ 71,422 357,895 $ 30,939 485,162 Interest income (5,772 ) (40,024 ) (5,106 ) (43,452 ) Reclassifications from nonaccretable balance, net 11,974 26,840 249 774 Other (a) — 278 — 8,486 Balance at end of period $ 77,624 344,989 $ 26,082 450,970 Six months ended June 30 2015 2014 Purchased Other Purchased Other (in thousands) Balance at beginning of period $ 76,518 397,379 $ 37,230 538,633 Interest income (10,978 ) (81,301 ) (11,434 ) (96,085 ) Reclassifications from nonaccretable balance, net 12,084 27,023 286 774 Other (a) — 1,888 — 7,648 Balance at end of period $ 77,624 344,989 $ 26,082 450,970 (a) Other changes in expected cash flows including changes in interest rates and prepayment assumptions. A summary of current, past due and nonaccrual loans as of June 30, 2015 and December 31, 2014 follows: Current 30-89 90 Days or Purchased Nonaccrual Total Non- Acquired (in thousands) June 30, 2015 Commercial, financial, leasing, etc. $ 19,852,368 36,637 4,777 1,628 5,273 210,345 $ 20,111,028 Real estate: Commercial 22,487,721 156,567 17,079 17,919 52,115 167,520 22,898,921 Residential builder and developer 1,666,183 4,233 — 6,603 73,628 56,854 1,807,501 Other commercial construction 3,642,229 43,683 6,112 2,834 20,059 21,149 3,736,066 Residential 7,525,761 197,893 207,195 18,972 15,804 164,721 8,130,346 Residential Alt-A 234,859 11,152 — — — 68,185 314,196 Consumer: Home equity lines and loans 5,765,082 31,446 — 12,371 2,361 78,250 5,889,510 Automobile 2,134,000 29,906 — — — 15,156 2,179,062 Other 2,996,396 31,591 3,405 18,264 — 14,966 3,064,622 Total $ 66,304,599 543,108 238,568 78,591 169,240 797,146 $ 68,131,252 4. Loans and leases and the allowance for credit losses, continued Current 30-89 90 Days or Purchased Nonaccrual Total Non- Acquired (in thousands) December 31, 2014 Commercial, financial, leasing, etc. $ 19,228,265 37,246 1,805 6,231 10,300 177,445 $ 19,461,292 Real estate: Commercial 22,208,491 118,704 22,170 14,662 51,312 141,600 22,556,939 Residential builder and developer 1,273,607 11,827 492 9,350 98,347 71,517 1,465,140 Other commercial construction 3,484,932 17,678 — — 17,181 25,699 3,545,490 Residential 7,640,368 226,932 216,489 35,726 18,223 180,275 8,318,013 Residential Alt-A 249,810 11,774 — — — 77,704 339,288 Consumer: Home equity lines and loans 5,859,378 42,945 — 27,896 2,374 89,291 6,021,884 Automobile 1,931,138 30,500 — 133 — 17,578 1,979,349 Other 2,909,791 33,295 4,064 16,369 — 18,042 2,981,561 Total $ 64,785,780 530,901 245,020 110,367 197,737 799,151 $ 66,668,956 (a) Acquired loans that were recorded at fair value at acquisition date. This category does not include purchased impaired loans that are presented separately. (b) Accruing loans that were impaired at acquisition date and were recorded at fair value. One-to-four family residential mortgage loans originated for sale were $479 million and $435 million at June 30, 2015 and December 31, 2014, respectively. Commercial mortgage loans held for sale were $320 million at June 30, 2015 and $308 million at December 31, 2014. Changes in the allowance for credit losses for the three months ended June 30, 2015 were as follows: Commercial, Real Estate Commercial Residential Consumer Unallocated Total (in thousands) Beginning balance $ 281,069 317,375 60,741 186,052 76,136 $ 921,373 Provision for credit losses 9,737 (3,652 ) 1,624 21,016 1,275 30,000 Net charge-offs Charge-offs (7,728 ) (3,470 ) (3,309 ) (18,455 ) — (32,962 ) Recoveries 3,672 1,041 1,238 5,625 — 11,576 Net charge-offs (4,056 ) (2,429 ) (2,071 ) (12,830 ) — (21,386 ) Ending balance $ 286,750 311,294 60,294 194,238 77,411 $ 929,987 Changes in the allowance for credit losses for the three months ended June 30, 2014 were as follows: Commercial, Real Estate Commercial Residential Consumer Unallocated Total (in thousands) Beginning balance $ 276,835 324,805 77,062 162,134 75,932 $ 916,768 Provision for credit losses 25,556 (12,229 ) (1,957 ) 18,676 (46 ) 30,000 Net charge-offs Charge-offs (14,142 ) (2,814 ) (5,478 ) (19,404 ) — (41,838 ) Recoveries 4,002 1,492 2,777 4,465 — 12,736 Net charge-offs (10,140 ) (1,322 ) (2,701 ) (14,939 ) — (29,102 ) Ending balance $ 292,251 311,254 72,404 165,871 75,886 $ 917,666 Changes in the allowance for credit losses for the six months ended June 30, 2015 were as follows: Commercial, Real Estate 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 11,179 11,890 2,584 40,590 1,757 68,000 Net charge-offs Charge-offs (20,078 ) (10,149 ) (6,427 ) (43,784 ) — (80,438 ) Recoveries 7,611 1,626 2,227 11,399 — 22,863 Net charge-offs (12,467 ) (8,523 ) (4,200 ) (32,385 ) — (57,575 ) Ending balance $ 286,750 311,294 60,294 194,238 77,411 $ 929,987 Changes in the allowance for credit losses for the six months ended June 30, 2014 were as follows: Commercial, Real Estate Commercial Residential Consumer Unallocated Total (in thousands) Beginning balance $ 273,383 324,978 78,656 164,644 75,015 $ 916,676 Provision for credit losses 38,154 (12,113 ) 2,271 32,817 871 62,000 Net charge-offs Charge-offs (28,951 ) (6,300 ) (12,931 ) (41,095 ) — (89,277 ) Recoveries 9,665 4,689 4,408 9,505 — 28,267 Net charge-offs (19,286 ) (1,611 ) (8,523 ) (31,590 ) — (61,010 ) Ending balance $ 292,251 311,254 72,404 165,871 75,886 $ 917,666 Despite the above allocation, the allowance for credit losses is general in nature and is available to absorb losses from any loan or lease type. In establishing the allowance for credit losses, the Company estimates losses attributable to specific troubled credits identified through both normal and detailed or intensified credit review processes and also estimates losses inherent in other loans and leases on a collective basis. For purposes of determining the level of the allowance for credit losses, the Company evaluates its loan and lease portfolio by loan type. The amounts of loss components in the Company’s loan and lease portfolios are determined through a loan by loan analysis of larger balance commercial loans and commercial real estate loans that are in nonaccrual status and by applying loss factors to groups of loan balances based on loan type and management’s classification of such loans under the Company’s loan grading system. Measurement of the specific loss components is typically based on expected future cash flows, collateral values and other factors that may impact the borrower’s ability to pay. In determining the allowance for credit losses, the Company utilizes a loan grading system which is applied to commercial and commercial real estate credits on an individual loan basis. Loan officers are responsible for assigning grades to these loans based on standards outlined in the Company’s Credit Policy. Internal loan grades are also monitored by the Company’s loan review department to ensure consistency and strict adherence to the prescribed standards. Loan grades are assigned loss component factors that reflect the Company’s loss estimate for each group of loans and leases. Factors considered in assigning loan grades and loss component factors include borrower-specific information related to expected future cash flows and operating results, collateral values, geographic location, financial condition and performance, payment status, and other information; levels of and trends in portfolio charge-offs and recoveries; levels of and trends in portfolio delinquencies and impaired loans; changes in the risk profile of specific portfolios; trends in volume and terms of loans; effects of changes in credit concentrations; and observed trends and practices in the banking industry. As updated appraisals are obtained on individual loans or other events in the market place indicate that collateral values have significantly changed, individual loan grades are adjusted as appropriate. Changes in other factors cited may also lead to loan grade changes at any time. Except for consumer and residential real estate loans that are considered smaller balance homogenous loans and acquired loans that are evaluated on an aggregated basis, the Company considers a loan to be impaired for purposes of applying GAAP when, based on current information and events, it is probable that the Company will be unable to collect all amounts according to the contractual terms of the loan agreement or the loan is delinquent 90 days. Regardless of loan type, the Company considers a loan to be impaired if it qualifies as a troubled debt restructuring. Modified loans, including smaller balance homogenous loans, that are considered to be troubled debt restructurings are evaluated for impairment giving consideration to the impact of the modified loan terms on the present value of the loan’s expected cash flows. The following tables provide information with respect to loans and leases that were considered impaired as of June 30, 2015 and December 31, 2014 and for the three-month and six-month periods ended June 30, 2015 and June 30, 2014: June 30, 2015 December 31, 2014 Recorded Unpaid Related Recorded Unpaid Related (in thousands) With an allowance recorded: Commercial, financial, leasing, etc. $ 122,574 147,028 31,098 132,340 165,146 31,779 Real estate: Commercial 105,064 120,905 18,390 83,955 96,209 14,121 Residential builder and developer 7,808 10,439 661 17,632 22,044 805 Other commercial construction 3,091 4,542 514 5,480 6,484 900 Residential 84,241 102,237 4,931 88,970 107,343 4,296 Residential Alt-A 94,752 107,894 10,000 101,137 114,565 11,000 Consumer: Home equity lines and loans 21,235 22,219 3,531 19,771 20,806 6,213 Automobile 25,175 25,175 6,334 30,317 30,317 8,070 Other 19,256 19,256 5,458 18,973 18,973 5,459 483,196 559,695 80,917 498,575 581,887 82,643 With no related allowance recorded: Commercial, financial, leasing, etc. 116,982 138,635 — 73,978 81,493 — Real estate: Commercial 72,094 79,541 — 66,777 78,943 — Residential builder and developer 53,843 94,700 — 58,820 96,722 — Other commercial construction 18,524 39,347 — 20,738 41,035 — Residential 16,174 26,120 — 16,815 26,750 — Residential Alt-A 23,535 40,517 — 26,752 46,964 — 301,152 418,860 — 263,880 371,907 — Total: Commercial, financial, leasing, etc. 239,556 285,663 31,098 206,318 246,639 31,779 Real estate: Commercial 177,158 200,446 18,390 150,732 175,152 14,121 Residential builder and developer 61,651 105,139 661 76,452 118,766 805 Other commercial construction 21,615 43,889 514 26,218 47,519 900 Residential 100,415 128,357 4,931 105,785 134,093 4,296 Residential Alt-A 118,287 148,411 10,000 127,889 161,529 11,000 Consumer: Home equity lines and loans 21,235 22,219 3,531 19,771 20,806 6,213 Automobile 25,175 25,175 6,334 30,317 30,317 8,070 Other 19,256 19,256 5,458 18,973 18,973 5,459 Total $ 784,348 978,555 80,917 762,455 953,794 82,643 Three months ended Three months ended Interest income Interest income Average Total Cash Average Total Cash (in thousands) Commercial, financial, leasing, etc. $ 221,952 502 502 150,625 220 220 Real estate: Commercial 153,105 1,004 1,004 207,633 869 869 Residential builder and developer 66,334 131 131 91,614 39 39 Other commercial construction 23,614 168 168 77,801 356 356 Residential 101,560 1,358 785 119,133 5,056 4,468 Residential Alt-A 120,286 1,650 697 134,895 1,733 660 Consumer: Home equity lines and loans 20,221 224 65 18,762 200 72 Automobile 26,123 416 43 36,631 589 74 Other 19,058 185 30 18,309 166 49 Total $ 752,253 5,638 3,425 855,403 9,228 6,807 Six months ended Six months ended Interest income Interest income Average Total Cash Average Total Cash (in thousands) Commercial, financial, leasing, etc. $ 218,285 1,106 1,106 142,466 768 768 Real estate: Commercial 153,088 2,106 2,106 196,529 1,795 1,795 Residential builder and developer 69,742 194 194 96,434 113 113 Other commercial construction 24,577 223 223 82,546 1,443 1,443 Residential 103,025 2,804 1,695 146,651 6,456 5,370 Residential Alt-A 122,970 3,260 1,344 137,273 3,359 1,219 Consumer: Home equity lines and loans 19,952 425 113 17,219 321 101 Automobile 27,568 866 97 38,007 1,214 161 Other 18,960 359 63 18,005 340 101 Total $ 758,167 11,343 6,941 875,130 15,809 11,071 In accordance with the previously described policies, the Company utilizes a loan grading system that is applied to all commercial loans and commercial real estate loans. Loan grades are utilized to differentiate risk within the portfolio and consider the expectations of default for each loan. Commercial loans and commercial real estate loans with a lower expectation of default are assigned one of ten possible “pass” loan grades and are generally ascribed lower loss factors when determining the allowance for credit losses. Loans with an elevated level of credit risk are classified as “criticized” and are ascribed a higher loss factor when determining the allowance for credit losses. Criticized loans may be classified as “nonaccrual” if the Company no longer expects to collect all amounts according to the contractual terms of the loan agreement or the loan is delinquent 90 days or more. All larger balance criticized commercial and commercial real estate loans are individually reviewed by centralized loan review personnel each quarter to determine the appropriateness of the assigned loan grade, including whether the loan should be reported as accruing or nonaccruing. Smaller balance criticized loans are analyzed by business line risk management areas to ensure proper loan grade classification. Furthermore, criticized nonaccrual commercial loans and commercial real estate loans are considered impaired and, as a result, specific loss allowances on such loans are established within the allowance for credit losses to the extent appropriate in each individual instance. The following table summarizes the loan grades applied to the various classes of the Company’s commercial and commercial real estate loans. Real Estate Commercial, Commercial Residential Other (in thousands) June 30, 2015 Pass $ 19,079,109 21,885,377 1,690,496 3,549,397 Criticized accrual 821,574 846,024 60,151 165,520 Criticized nonaccrual 210,345 167,520 56,854 21,149 Total $ 20,111,028 22,898,921 1,807,501 3,736,066 December 31, 2014 Pass $ 18,695,440 21,837,022 1,347,778 3,347,522 Criticized accrual 588,407 578,317 45,845 172,269 Criticized nonaccrual 177,445 141,600 71,517 25,699 Total $ 19,461,292 22,556,939 1,465,140 3,545,490 In determining the allowance for credit losses, residential real estate loans and consumer loans are generally evaluated collectively after considering such factors as payment performance and recent loss experience and trends, which are mainly driven by current collateral values in the market place as well as the amount of loan defaults. Loss rates on such loans are determined by reference to recent charge-off history and are evaluated (and adjusted if deemed appropriate) through consideration of other factors including near-term forecasted loss estimates developed by the Company’s Credit Department. In arriving at such forecasts, the Company considers the current estimated fair value of its collateral based on geographical adjustments for home price depreciation/appreciation and overall borrower repayment performance. With regard to collateral values, the realizability of such values by the Company contemplates repayment of any first lien position prior to recovering amounts on a second lien position. Residential real estate loans and outstanding balances of home equity loans and lines of credit that are more than 150 days past due are generally evaluated for collectibility on a loan-by-loan basis giving consideration to estimated collateral values. The carrying value of residential real estate loans and home equity loans and lines of credit for which a partial charge-off has been recognized aggregated $59 million and $20 million, respectively, at June 30, 2015 and $63 million and $18 million, respectively, at December 31, 2014. Residential real estate loans and home equity loans and lines of credit that were more than 150 days past due but did not require a partial charge-off because the net realizable value of the collateral exceeded the outstanding customer balance totaled $23 million and $28 million, respectively, at June 30, 2015 and $27 million and $28 million, respectively, at December 31, 2014. The Company also measures additional losses for purchased impaired loans when it is probable that the Company will be unable to collect all cash flows expected at acquisition plus additional cash flows expected to be collected arising from changes in estimates after acquisition. The determination of the allocated portion of the allowance for credit losses is very subjective. Given that inherent subjectivity and potential imprecision involved in determining the allocated portion of the allowance for credit losses, the Company also provides an inherent unallocated portion of the allowance. The unallocated portion of the allowance is intended to recognize probable losses that are not otherwise identifiable and includes management’s subjective determination of amounts necessary to provide for the possible use of imprecise estimates in determining the allocated portion of the allowance. Therefore, the level of the unallocated portion of the allowance is primarily reflective of the inherent imprecision in the various calculations used in determining the allocated portion of the allowance for credit losses. Other factors that could also lead to changes in the unallocated portion include the effects of expansion into new markets for which the Company does not have the same degree of familiarity and experience regarding portfolio performance in changing market conditions, the introduction of new loan and lease product types, and other risks associated with the Company’s loan portfolio that may not be specifically identifiable. The allocation of the allowance for credit losses summarized on the basis of the Company’s impairment methodology was as follows: Commercial, Real Estate Commercial Residential Consumer Total (in thousands) June 30, 2015 Individually evaluated for impairment $ 31,098 19,296 14,904 15,323 $ 80,621 Collectively evaluated for impairment 253,312 290,853 43,428 177,444 765,037 Purchased impaired 2,340 1,145 1,962 1,471 6,918 Allocated $ 286,750 311,294 60,294 194,238 852,576 Unallocated 77,411 Total $ 929,987 December 31, 2014 Individually evaluated for impairment $ 31,779 15,490 14,703 19,742 $ 81,714 Collectively evaluated for impairment 251,607 291,244 45,061 165,140 753,052 Purchased impaired 4,652 1,193 2,146 1,151 9,142 Allocated $ 288,038 307,927 61,910 186,033 843,908 Unallocated 75,654 Total $ 919,562 The recorded investment in loans and leases summarized on the basis of the Company’s impairment methodology was as follows: Commercial, Real Estate Commercial Residential Consumer Total (in thousands) June 30, 2015 Individually evaluated for impairment $ 239,556 259,441 218,410 65,666 $ 783,073 Collectively evaluated for impairment 19,866,199 28,037,245 8,210,328 11,065,167 67,178,939 Purchased impaired 5,273 145,802 15,804 2,361 169,240 Total $ 20,111,028 28,442,488 8,444,542 11,133,194 $ 68,131,252 December 31, 2014 Individually evaluated for impairment $ 206,318 252,347 232,398 69,061 $ 760,124 Collectively evaluated for impairment 19,244,674 27,148,382 8,406,680 10,911,359 65,711,095 Purchased impaired 10,300 166,840 18,223 2,374 197,737 Total $ 19,461,292 27,567,569 8,657,301 10,982,794 $ 66,668,956 During the normal course of business, the Company modifies loans to maximize recovery efforts. If the borrower is experiencing financial difficulty and a concession is granted, the Company considers such modifications as troubled debt restructurings and classifies those loans as either nonaccrual loans or renegotiated loans. The types of concessions that the Company grants typically include principal deferrals and interest rate concessions, but may also include other types of concessions. The tables below summarize the Company’s loan modification activities that were considered troubled debt restructurings for the three months ended June 30, 2015 and 2014: Recorded investment Financial effects of Three months ended June 30, 2015 Number Pre- Post- Recorded Interest (dollars in thousands) Commercial, financial, leasing, etc. Principal deferral 30 $ 16,018 $ 15,355 $ (663 ) $ — Other 2 8,991 8,883 (108 ) — Combination of concession types 2 15,889 17,864 1,975 (239 ) Real estate: Commercial Principal deferral 15 38,983 37,585 (1,398 ) — Combination of concession types 1 436 436 — (53 ) Residential builder and developer Principal deferral 1 9,252 9,200 (52 ) — Residential Principal deferral 12 693 754 61 — Combination of concession types 9 961 1,066 105 (144 ) Residential Alt-A Principal deferral 1 161 161 — — Combination of concession types 2 424 426 2 (26 ) Consumer: Home equity lines and loans Principal deferral 1 1,198 1,198 — — Combination of concession types 14 1,356 1,356 — (212 ) Automobile Principal deferral 63 615 615 — — Interest rate reduction 4 95 95 — (7 ) Other 13 21 21 — — Combination of concession types 9 138 138 — (4 ) Other Principal deferral 27 770 770 — — Other 2 21 21 — — Combination of concession types 10 43 43 — (7 ) Total 218 $ 96,065 $ 95,987 $ (78 ) $ (692 ) (a) Financial effects impacting the recorded investment included principal payments or advances, charge-offs and capitalized escrow arrearages. (b) Represents the present value of interest rate concessions discounted at the effective rate of the original loan. Recorded investment Financial effects of Three months ended June 30, 2014 Number Pre- Post- Recorded Interest (dollars in thousands) Commercial, financial, leasing, etc. Principal deferral 21 $ 4,414 $ 4,351 $ (63 ) $ — Other 1 19,593 19,593 — — Combination of concession types 3 9,795 9,727 (68 ) (10 ) Real estate: Commercial Principal deferral 11 8,327 8,314 (13 ) — Interest rate reduction 1 255 252 (3 ) (48 ) Combination of concession types 1 63 61 (2 ) (9 ) Residential builder and developer Principal deferral 1 1,398 1,398 — — Other commercial construction Principal deferral 2 6,407 6,318 (89 ) — Residential Principal deferral 3 142 166 24 — Combination of concession types 8 923 991 68 (66 ) Residential Alt-A Principal deferral 3 662 698 36 — Combination of concession types 6 1,006 1,029 23 (220 ) Consumer: Home equity lines and loans Interest rate reduction 5 341 341 — (76 ) Combination of concession types 21 1,772 1,772 — (204 ) Automobile Principal deferral 43 603 603 — — Interest rate reduction 3 60 60 — (3 ) Other 8 47 47 — — Combination of concession types 23 341 341 — (36 ) Other Principal deferral 7 38 38 — — Interest rate reduction 3 291 291 — (63 ) Combination of concession types 19 906 906 — (276 ) Total 193 $ 57,384 $ 57,297 $ (87 ) $ (1,011 ) (a) Financial effects impacting the recorded investment included principal payments or advances, charge-offs and capitalized escrow arrearages. (b) Represents the present value of interest rate concessions discounted at the effective rate of the original loan. The tables below summarize the Company’s loan modification activities that were considered troubled debt restructurings for the six months ended June 30, 2015 and 2014: Recorded investment Financial effects of Six months ended June 30, 2015 Number Pre- Post- Recorded Interest (dollars in thousands) Commercial, financial, leasing, etc. Principal deferral 51 $ 17,590 $ 16,912 $ (678 ) $ — Interest rate reduction 1 99 99 — (19 ) Other 2 8,991 8,883 (108 ) — Combination of concession types 5 25,044 24,853 (191 ) (239 ) Real estate: Commercial Principal deferral 22 42,775 41,361 (1,414 ) — Combination of concession types 5 2,082 2,073 (9 ) (105 ) Residential builder and developer Principal deferral 2 10,650 10,598 (52 ) — Residential Principal deferral 19 1,414 1,496 82 — Combination of concession types 12 1,255 1,415 160 (178 ) Residential Alt-A Principal deferral 1 161 161 — — Combination of concession types 3 634 636 2 (30 ) Consumer: Home equity lines and loans Principal deferral 2 1,219 1,219 — — Combination of concession types 19 1,552 1,552 — (225 ) Automobile Principal deferral 98 918 918 — — Interest rate reduction 7 137 137 — (10 ) Other 23 41 41 — — Combination of concession types 17 222 222 — (11 ) Other Principal deferral 49 1,066 1,066 — — Other 7 80 80 — — Combination of concession types 23 267 267 — (32 ) Total 368 $ 116,197 $ 113,989 $ (2,208 ) $ (849 ) (a) Financial effects impacting the recorded investment included principal payments or advances, charge-offs and capitalized escrow arrearages. (b) Represents the present value of interest rate concessions discounted at the effective rate of the original loan. Recorded investment Financial effects of Six months ended June 30, 2014 Number Pre- Post- Recorded Interest (dollars in thousands) Commercial, financial, leasing, etc. Principal deferral 51 $ 19,368 $ 19,199 $ (169 ) $ — Other 1 19,593 19,593 — — Combination of concession types 5 9,836 9,766 (70 ) (14 ) Real estate: Commercial Principal deferral 24 15,371 15,316 (55 ) — Interest rate reduction 1 255 252 (3 ) (48 ) Combination of concession types 2 409 462 53 (113 ) Residential builder and developer Principal deferral 1 1,398 1,398 — — Other commercial construction Principal deferral 3 6,558 6,469 (89 ) — Residential Principal deferral 16 1,744 1,829 85 — Interest rate reduction 1 98 104 6 (32 ) Other 1 188 188 — — Combination of concession types 22 3,111 3,151 40 (348 ) Residential Alt-A Principal deferral 5 828 900 72 — Combination of concession types 16 2,752 2,765 13 (281 ) Consumer: Home equity lines and loans Principal deferral 3 280 280 — — Interest rate reduction 5 341 341 — (76 ) Combination of concession types 36 3,628 3,628 — (376 ) Automobile Principal deferral 123 1,596 1,596 — — Interest rate reduction 3 60 60 — (3 ) Other 19 108 108 — — Combination of concession types 46 591 591 — (62 ) Other Principal deferral 15 93 93 — — Interest rate reduction 3 291 291 — (63 ) Other 1 45 45 — — Combination of concession types 33 1,372 1,372 — (464 ) Total 436 $ 89,914 $ 89,797 $ (117 ) $ (1,880 ) (a) Financial effects impacting the recorded investment included principal payments or advances, charge-offs and capitalized escrow arrearages. (b) Represents the present value of interest rate concessions discounted at the effective rate of the original loan. Troubled debt restructurings are considered to be impaired loans and for purposes of establishing the allowance for credit losses are evaluated for impairment giving consideration to the impact of the modified loan terms on the present value of the loan’s expected cash flows. Impairment of troubled debt restructurings that have subsequently defaulted may also be measured based on the loan’s observable market price or the fair value of collateral if the loan is collateral-dependent. Charge-offs may also be recognized on troubled debt restructurings that have subsequently defaulted. Loans that were modified as troubled debt restructurings during the twelve months ended June 30, 2015 and 2014 and for which there was a subsequent payment default during the six-month periods ended June 30, 2015 and 2014, respectively, were not material. Effective January 1, 2015, the Company adopted amended accounting and disclosure guidance for reclassification of residential real estate collateralized consumer mortgage loans upon foreclosure. The amended guidance clarifies that an in-substance repossession or foreclosure occurs and a creditor is considered to have received physical possession of residential real estate property collateralizing a consumer mortgage loan upon either (1) the creditor obtaining legal title to the residential real estate property upon completion of a foreclosure or (2) the borrower conveying all interest in the residential real estate property to the creditor to satisfy that loan through completion of a deed in lieu of foreclosure or through a similar legal agreement. The adoption resulted in an insignificant increase in other real estate owned. The amount of foreclosed residential real estate property held by the Company was $43 million and $44 million at June 30, 2015 and December 31, 2014, respectively. At June 30, 2015, there were $158 million in loans secured by residential real estate that were in the process of foreclosure.

Borrowings

Borrowings	6 Months Ended
	Jun. 30, 2015
Debt Disclosure [Abstract]
Borrowings	5. Borrowings During February 2015, M&T Bank issued $1.5 billion of fixed rate senior notes pursuant to a Bank Note Program, of which $750 million have a 2.10% interest rate and mature in 2020 and $750 million have a 2.90% interest rate and mature in 2025. M&T had $513 million of fixed and floating rate junior subordinated deferrable interest debentures (“Junior Subordinated Debentures”) outstanding at June 30, 2015 that are held by various trusts that were issued in connection with the issuance by those trusts of preferred capital securities (“Capital Securities”) and common securities (“Common Securities”). The proceeds from the issuances of the Capital Securities and the Common Securities were used by the trusts to purchase the Junior Subordinated Debentures. The Common Securities of each of those trusts are wholly owned by M&T and are the only class of each trust’s securities possessing general voting powers. The Capital Securities represent preferred undivided interests in the assets of the corresponding trust. Holders of the Capital Securities receive preferential cumulative cash distributions unless M&T exercises its right to extend the payment of interest on the Junior Subordinated Debentures as allowed by the terms of each such debenture, in which case payment of distributions on the respective Capital Securities will be deferred for comparable periods. During an extended interest period, M&T may not pay dividends or distributions on, or repurchase, redeem or acquire any shares of its capital stock. In general, the agreements governing the Capital Securities, in the aggregate, provide a full, irrevocable and unconditional guarantee by M&T of the payment of distributions on, the redemption of, and any liquidation distribution with respect to the Capital Securities. The obligations under such guarantee and the Capital Securities are subordinate and junior in right of payment to all senior indebtedness of M&T. The Capital Securities will remain outstanding until the Junior Subordinated Debentures are repaid at maturity, are redeemed prior to maturity or are distributed in liquidation to the Trusts. The Capital Securities are mandatorily redeemable in whole, but not in part, upon repayment at the stated maturity dates (ranging from 2027 to 2033) of the Junior Subordinated Debentures or the earlier redemption of the Junior Subordinated Debentures in whole upon the occurrence of one or more events set forth in the indentures relating to the Capital Securities, and in whole or in part at any time after an optional redemption prior to contractual maturity contemporaneously with the optional redemption of the related Junior Subordinated Debentures in whole or in part, subject to possible regulatory approval. On April 15, 2015, M&T redeemed all of the issued and outstanding Capital Securities issued by M&T Capital Trust I, M&T Capital Trust II and M&T Capital Trust III, and the related Junior Subordinated Debentures held by those respective trusts. In the aggregate, $323 million of Junior Subordinated NOTES TO FINANCIAL STATEMENTS, CONTINUED 5. Borrowings, continued Debentures were redeemed. In February 2014, M&T redeemed all of the issued and outstanding 8.5% $350 million Capital Securities issued by M&T Capital Trust IV and the related Junior Subordinated Debentures held by M&T Capital Trust IV. Also included in long-term borrowings are agreements to repurchase securities of $1.4 billion at each of June 30, 2015 and December 31, 2014. The agreements reflect various repurchase dates in 2016 and 2017 and are subject to legally enforceable master netting arrangements, however the Company has not offset any amounts related to these agreements in its consolidated financial statements. The Company posted collateral consisting primarily of government guaranteed mortgage-backed securities of $1.5 billion at each of June 30, 2015 and December 31, 2014.

Shareholders' equity

Shareholders' equity	6 Months Ended
	Jun. 30, 2015
Equity [Abstract]
Shareholders' equity	6. Shareholders’ equity M&T is authorized to issue 1,000,000 shares of preferred stock with a $1.00 par value per share. Preferred shares outstanding rank senior to common shares both as to dividends and liquidation preference, but have no general voting rights. Issued and outstanding preferred stock of M&T as of June 30, 2015 and December 31, 2014 is presented below: Shares Carrying value (dollars in thousands) Series A (a) Fixed Rate Cumulative Perpetual Preferred Stock, Series A, $1,000 liquidation preference per share 230,000 $ 230,000 Series C (a) Fixed Rate Cumulative Perpetual Preferred Stock, Series C, $1,000 liquidation preference per share 151,500 $ 151,500 Series D (b) Fixed Rate Non-Cumulative Perpetual Preferred Stock, Series D, $10,000 liquidation preference per share 50,000 $ 500,000 Series E (c) Fixed-to-Floating Rate Non-Cumulative Perpetual Preferred Stock Series E, $1,000 liquidation preference per share 350,000 $ 350,000 (a) Dividends, if declared, are paid at 6.375%. Warrants to purchase M&T common stock at $73.86 per share issued in connection with the Series A preferred stock expire in 2018 and totaled 719,175 at June 30, 2015 and 721,490 at December 31, 2014. (b) Dividends, if declared, are paid semi-annually at a rate of 6.875% per year. The shares are redeemable in whole or in part on or after June 15, 2016. Notwithstanding M&T’s option to redeem the shares, if an event occurs such that the shares no longer qualify as Tier 1 capital, M&T may redeem all of the shares within 90 days following that occurrence. (c) Dividends, if declared, are paid semi-annually at a rate of 6.45% through February 14, 2024 and thereafter will be paid quarterly at a rate of the three-month London Interbank Offered Rate (“LIBOR”) plus 361 basis points (hundredths of one percent). The shares are redeemable in whole or in part on or after February 15, 2024. Notwithstanding M&T’s option to redeem the shares, if an event occurs such that the shares no longer qualify as Tier 1 capital, M&T may redeem all of the shares within 90 days following that occurrence. In addition to the Series A warrants mentioned in (a) above, a warrant to purchase 95,383 shares of M&T common stock at $518.96 per share was outstanding at June 30, 2015 and December 31, 2014. The obligation under that warrant was assumed by M&T in an acquisition.

Pension plans and other postret

Pension plans and other postretirement benefits	6 Months Ended
	Jun. 30, 2015
Compensation and Retirement Disclosure [Abstract]
Pension plans and other postretirement benefits	7. Pension plans and other postretirement benefits The Company provides defined benefit pension and other postretirement benefits (including health care and life insurance benefits) to qualified retired employees. Net periodic defined benefit cost for defined benefit plans consisted of the following: Pension Other Three months ended June 30 2015 2014 2015 2014 (in thousands) Service cost $ 5,832 5,160 174 152 Interest cost on projected benefit obligation 17,732 17,331 652 714 Expected return on plan assets (23,476 ) (22,859 ) — — Amortization of prior service credit (1,478 ) (1,626 ) (329 ) (329 ) Amortization of net actuarial loss 11,237 3,897 28 — Net periodic benefit cost $ 9,847 1,903 525 537 Pension Other Six months ended June 30 2015 2014 2015 2014 (in thousands) Service cost $ 11,832 10,260 374 302 Interest cost on projected benefit obligation 35,507 34,581 1,302 1,389 Expected return on plan assets (47,051 ) (45,784 ) — — Amortization of prior service credit (3,003 ) (3,276 ) (679 ) (679 ) Amortization of net actuarial loss 22,412 7,247 53 — Net periodic benefit cost $ 19,697 3,028 1,050 1,012 Expense incurred in connection with the Company’s defined contribution pension and retirement savings plans totaled $13,346,000 and $12,673,000 for the three months ended June 30, 2015 and 2014, respectively, and $30,096,000 and $28,405,000 for the six months ended June 30, 2015 and 2014, respectively.

Earnings per common share

Earnings per common share	6 Months Ended
	Jun. 30, 2015
Earnings Per Share [Abstract]
Earnings per common share	8. Earnings per common share The computations of basic earnings per common share follow: Three months ended June 30 Six months ended June 30 2015 2014 2015 2014 (in thousands, except per share) Income available to common shareholders: Net income $ 286,688 284,336 $ 528,301 513,353 Less: Preferred stock dividends (a) (20,317 ) (20,443 ) (40,635 ) (35,117 ) Net income available to common equity 266,371 263,893 487,666 478,236 Less: Income attributable to unvested stock-based compensation awards (2,900 ) (3,213 ) (5,371 ) (5,832 ) Net income available to common shareholders $ 263,471 260,680 $ 482,295 472,404 Weighted-average shares outstanding: Common shares outstanding (including common stock issuable) and unvested stock-based compensation awards 133,818 132,473 133,680 132,139 Less: Unvested stock-based compensation awards (1,462 ) (1,617 ) (1,477 ) (1,603 ) Weighted-average shares outstanding 132,356 130,856 132,203 130,536 Basic earnings per common share $ 1.99 1.99 $ 3.65 3.62 (a) Including impact of not as yet declared cumulative dividends. The computations of diluted earnings per common share follow: Three months ended June 30 Six months ended June 30 2015 2014 2015 2014 (in thousands, except per share) Net income available to common equity $ 266,371 263,893 $ 487,666 478,236 Less: Income attributable to unvested stock-based compensation awards (2,890 ) (3,198 ) (5,353 ) (5,807 ) Net income available to common shareholders $ 263,481 260,695 $ 482,313 472,429 Adjusted weighted-average shares outstanding: Common and unvested stock-based compensation awards 133,818 132,473 133,680 132,139 Less: Unvested stock-based compensation awards (1,462 ) (1,617 ) (1,477 ) (1,603 ) Plus: Incremental shares from assumed conversion of stock-based compensation awards and warrants to purchase common stock 760 972 741 943 Adjusted weighted-average shares outstanding 133,116 131,828 132,944 131,479 Diluted earnings per common share $ 1.98 1.98 $ 3.63 3.59 GAAP defines unvested share-based awards that contain nonforfeitable rights to dividends or dividend equivalents (whether paid or unpaid) as participating securities that shall be included in the computation of earnings per common share pursuant to the two-class method. The Company has issued stock-based compensation awards in the form of restricted stock and restricted stock units, which, in accordance with GAAP, are considered participating securities. Stock-based compensation awards and warrants to purchase common stock of M&T representing approximately 1.6 million and 1.7 million common shares during the three-month periods ended June 30, 2015 and 2014, respectively, and 2.1 million and 2.4 million common shares during the six-month periods ended June 30, 2015 and 2014, respectively, were not included in the computations of diluted earnings per common share because the effect on those periods would have been antidilutive.

Comprehensive income

Comprehensive income	6 Months Ended
	Jun. 30, 2015
Equity [Abstract]
Comprehensive income	9. Comprehensive income The following tables display the components of other comprehensive income (loss) and amounts reclassified from accumulated other comprehensive income (loss) to net income: Investment Securities With All Defined Other Total Income Net (in thousands) Balance – January 1, 2015 $ 7,438 201,828 (503,027 ) (4,082 ) $ (297,843 ) 116,849 $ (180,994 ) Other comprehensive income before reclassifications: Unrealized holding gains, net 5,670 (85,602 ) — — (79,932 ) 31,617 (48,315 ) Foreign currency translation adjustment — — — (779 ) (779 ) 261 (518 ) Gains on cash flow hedges — — — 1,453 1,453 (568 ) 885 Total other comprehensive income before reclassifications 5,670 (85,602 ) — 674 (79,258 ) 31,310 (47,948 ) Amounts reclassified from accumulated other comprehensive income that (increase) decrease net income: Accretion of unrealized holding losses on held-to-maturity (“HTM”) securities — 1,589 — — 1,589 (b) (621 ) 968 Losses realized in net income — 108 — — 108 (c) (40 ) 68 Accretion of net gain on terminated cash flow hedges — — — (63 ) (63 ) (d) 25 (38 ) Amortization of prior service credit — — (3,682 ) — (3,682 ) (e) 1,640 (2,042 ) Amortization of actuarial losses — — 22,465 — 22,465 (e) (9,981 ) 12,484 Total reclassifications — 1,697 18,783 (63 ) 20,417 (8,977 ) 11,440 Total gain (loss) during the period 5,670 (83,905 ) 18,783 611 (58,841 ) 22,333 (36,508 ) Balance – June 30, 2015 $ 13,108 117,923 (484,244 ) (3,471 ) $ (356,684 ) 139,182 $ (217,502 ) Investment Securities With All Defined Other Total Income Net (in thousands) Balance – January 1, 2014 $ 37,255 18,450 (161,617 ) 115 $ (105,797 ) 41,638 $ (64,159 ) Other comprehensive income before reclassifications: Unrealized holding gains, net 10,842 156,764 — — 167,606 (65,774 ) 101,832 Foreign currency translation adjustment — — — 479 479 (166 ) 313 Unrealized losses on cash flow hedges — — — (1,170 ) (1,170 ) 459 (711 ) Total other comprehensive income before reclassifications 10,842 156,764 — (691 ) 166,915 (65,481 ) 101,434 Amounts reclassified from accumulated other comprehensive income that (increase) decrease net income: Accretion of unrealized holding losses on HTM securities 1 1,702 — — 1,703 (b) (669 ) 1,034 Amortization of prior service credit — — (3,955 ) — (3,955 ) (e) 1,552 (2,403 ) Amortization of actuarial losses — — 7,247 — 7,247 (e) (2,845 ) 4,402 Total reclassifications 1 1,702 3,292 — 4,995 (1,962 ) 3,033 Total gain (loss) during the period 10,843 158,466 3,292 (691 ) 171,910 (67,443 ) 104,467 Balance – June 30, 2014 $ 48,098 176,916 (158,325 ) (576 ) $ 66,113 (25,805 ) $ 40,308 (a) Other-than-temporary impairment (b) Included in interest income (c) Included in loss on bank investment securities (d) Included in interest expense (e) Included in salaries and employee benefits expense Accumulated other comprehensive income (loss), net consisted of the following: Investment securities Defined With OTTI All other plans Other Total (in thousands) Balance – December 31, 2014 $ 4,518 122,683 (305,589 ) (2,606 ) $ (180,994 ) Net gain (loss) during period 3,471 (50,750 ) 10,442 329 (36,508 ) Balance – June 30, 2015 $ 7,989 71,933 (295,147 ) (2,277 ) $ (217,502 )

Derivative financial instrument

Derivative financial instruments	6 Months Ended
	Jun. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative financial instruments	10. Derivative financial instruments As part of managing interest rate risk, the Company enters into interest rate swap agreements to modify the repricing characteristics of certain portions of the Company’s portfolios of earning assets and interest-bearing liabilities. The Company designates interest rate swap agreements utilized in the management of interest rate risk as either fair value hedges or cash flow hedges. Interest rate swap agreements are generally entered into with counterparties that meet established credit standards and most contain master netting and collateral provisions protecting the at-risk party. Based on adherence to the Company’s credit standards and the presence of the netting and collateral provisions, the Company believes that the credit risk inherent in these contracts was not significant as of June 30, 2015. The net effect of interest rate swap agreements was to increase net interest income by $11 million and $12 million for the three-month periods ended June 30, 2015 and 2014, respectively, and $22 million and $23 million for the six-month periods ended June 30, 2015 and 2014, respectively. Information about interest rate swap agreements entered into for interest rate risk management purposes summarized by type of financial instrument the swap agreements were intended to hedge follows: Notional Average Weighted- Fixed Variable (in thousands) (in years) June 30, 2015 Fair value hedges: Fixed rate long-term borrowings (a) $ 1,400,000 2.2 4.42 % 1.24 % December 31, 2014 Fair value hedges: Fixed rate long-term borrowings (a) $ 1,400,000 2.7 4.42 % 1.19 % (a) Under the terms of these agreements, the Company receives settlement amounts at a fixed rate and pays at a variable rate. The use of cash flow hedges to manage the variability of cash flows associated with the then-forecasted issuance of long-term debt did not have a significant impact on the Company’s consolidated financial position or results of operations. The Company utilizes commitments to sell residential and commercial real estate loans to hedge the exposure to changes in the fair value of real estate loans held for sale. Such commitments have generally been designated as fair value hedges. The Company also utilizes commitments to sell real estate loans to offset the exposure to changes in fair value of certain commitments to originate real estate loans for sale. Derivative financial instruments used for trading account purposes included interest rate contracts, foreign exchange and other option contracts, foreign exchange forward and spot contracts, and financial futures. Interest rate contracts entered into for trading account purposes had notional values of $17.2 billion and $17.6 billion at June 30, 2015 and December 31, 2014, respectively. The notional amounts of foreign currency and other option and futures contracts entered into for trading account purposes aggregated $1.6 billion and $1.3 billion at June 30, 2015 and December 31, 2014, respectively. Information about the fair values of derivative instruments in the Company’s consolidated balance sheet and consolidated statement of income follows: Asset derivatives Liability derivatives Fair value Fair value June 30, December 31, June 30, December 31, (in thousands) Derivatives designated and qualifying as hedging instruments Fair value hedges: Interest rate swap agreements (a) $ 63,501 73,251 $ — — Commitments to sell real estate loans (a) 12,150 728 579 4,217 75,651 73,979 579 4,217 Derivatives not designated and qualifying as hedging instruments Mortgage-related commitments to originate real estate loans for sale (a) 12,755 17,396 1,549 49 Commitments to sell real estate loans (a) 2,645 754 1,946 4,330 Trading: Interest rate contracts (b) 202,052 215,614 158,670 173,513 Foreign exchange and other option and futures contracts (b) 16,424 31,112 13,826 29,950 233,876 264,876 175,991 207,842 Total derivatives $ 309,527 338,855 $ 176,570 212,059 (a) Asset derivatives are reported in other assets and liability derivatives are reported in other liabilities. (b) Asset derivatives are reported in trading account assets and liability derivatives are reported in other liabilities. NOTES TO FINANCIAL STATEMENTS, CONTINUED 10. Derivative financial instruments, continued Amount of unrealized gain (loss) recognized Three months ended Three months ended Derivative Hedged item Derivative Hedged item (in thousands) Derivatives in fair value hedging relationships Interest rate swap agreements: Fixed rate long-term borrowings (a) $ (9,354 ) 8,952 $ (1,675 ) 1,358 Derivatives not designated as hedging instruments Trading: Interest rate contracts (b) $ 1,772 $ 1,384 Foreign exchange and other option and futures contracts (b) (711 ) (786 ) Total $ 1,061 $ 598 Amount of unrealized gain (loss) recognized Six months ended Six months ended Derivative Hedged item Derivative Hedged item (in thousands) Derivatives in fair value hedging relationships Interest rate swap agreements: Fixed rate long-term borrowings (a) $ (9,750 ) 9,113 $ (9,835 ) 9,278 Derivatives not designated as hedging instruments Trading: Interest rate contracts (b) $ 2,432 $ 1,082 Foreign exchange and other option and futures contracts (b) (878 ) (5,816 ) Total $ 1,554 $ (4,734 ) (a) Reported as other revenues from operations. (b) Reported as trading account and foreign exchange gains. NOTES TO FINANCIAL STATEMENTS, CONTINUED 10. Derivative financial instruments, continued In addition, the Company also has commitments to sell and commitments to originate residential and commercial real estate loans that are considered derivatives. The Company designates certain of the commitments to sell real estate loans as fair value hedges of real estate loans held for sale. The Company also utilizes commitments to sell real estate loans to offset the exposure to changes in the fair value of certain commitments to originate real estate loans for sale. As a result of these activities, net unrealized pre-tax gains related to hedged loans held for sale, commitments to originate loans for sale and commitments to sell loans were approximately $29 million and $28 million at June 30, 2015 and December 31, 2014, respectively. Changes in unrealized gains and losses are included in mortgage banking revenues and, in general, are realized in subsequent periods as the related loans are sold and commitments satisfied. The Company does not offset derivative asset and liability positions in its consolidated financial statements. The Company’s exposure to credit risk by entering into derivative contracts is mitigated through master netting agreements and collateral posting requirements. Master netting agreements covering interest rate and foreign exchange contracts with the same party include a right to set-off that becomes enforceable in the event of default, early termination or under other specific conditions. The aggregate fair value of derivative financial instruments in a liability position, which are subject to enforceable master netting arrangements, was $124 million and $161 million at June 30, 2015 and December 31, 2014, respectively. After consideration of such netting arrangements, the net liability positions with counterparties aggregated $72 million and $103 million at June 30, 2015 and December 31, 2014, respectively. The Company was required to post collateral relating to those positions of $65 million and $90 million at June 30, 2015 and December 31, 2014, respectively. Certain of the Company’s derivative financial instruments contain provisions that require the Company to maintain specific credit ratings from credit rating agencies to avoid higher collateral posting requirements. If the Company’s debt rating were to fall below specified ratings, the counterparties of the derivative financial instruments could demand immediate incremental collateralization on those instruments in a net liability position. The aggregate fair value of all derivative financial instruments with such credit risk-related contingent features in a net liability position on June 30, 2015 was $14 million, for which the Company had posted collateral of $8 million in the normal course of business. If the credit risk-related The aggregate fair value of derivative financial instruments in an asset position, which are subject to enforceable master netting arrangements, was $89 million and $104 million at June 30, 2015 and December 31, 2014, respectively. After consideration of such netting arrangements, the net asset positions with counterparties aggregated $37 million and $46 million at June 30, 2015 and December 31, 2014, respectively. Counterparties posted collateral relating to those positions of $37 million and $46 million at June 30, 2015 and December 31, 2014, respectively. Trading account interest rate swap agreements entered into with customers are subject to the Company’s credit risk standards and often contain collateral provisions. In addition to the derivative contracts noted above, the Company clears certain derivative transactions through a clearinghouse rather than directly with counterparties. Those transactions cleared through a clearinghouse require initial margin collateral and additional collateral for contracts in a net liability position. The net fair values of derivative instruments cleared through clearinghouses was a net liability position of $35 million at each of NOTES TO FINANCIAL STATEMENTS, CONTINUED 10. Derivative financial instruments, continued June 30, 2015 and December 31, 2014. Collateral posted with clearinghouses was $70 million and $61 million at June 30, 2015 and December 31, 2014, respectively.

Variable interest entities and

Variable interest entities and asset securitizations	6 Months Ended
	Jun. 30, 2015
Text Block [Abstract]
Variable interest entities and asset securitizations	11. Variable interest entities and asset securitizations During the three and six months ended June 30, 2015, the Company securitized approximately $23 million and $36 million, respectively, of one-to-four family residential real estate loans that had been originated for sale in guaranteed mortgage securitizations with the Government National Mortgage Association ( “ ” In accordance with GAAP, the Company determined that it was the primary beneficiary of a residential mortgage loan securitization trust considering its role as servicer and its retained subordinated interests in the trust. As a result, the Company has included the one-to-four family residential mortgage loans that were included in the trust in its consolidated financial statements. At June 30, 2015 and December 31, 2014, the carrying values of the loans in the securitization trust were $88 million and $98 million, respectively. The outstanding principal amount of mortgage-backed securities issued by the qualified special purpose trust that was held by parties unrelated to M&T at June 30, 2015 and December 31, 2014 was $14 million and $15 million, respectively. Because the transaction was non-recourse, the Company’s maximum exposure to loss as a result of its association with the trust at June 30, 2015 is limited to realizing the carrying value of the loans less the amount of the mortgage-backed securities held by third parties. As described in note 5, M&T has issued junior subordinated debentures payable to various trusts that have issued Capital Securities. M&T owns the common securities of those trust entities. The Company is not considered to be the primary beneficiary of those entities and, accordingly, the trusts are not included in the Company’s consolidated financial statements. At June 30, 2015 and December 31, 2014, the Company included the junior subordinated debentures as “long-term borrowings” in its consolidated balance sheet. The Company has recognized $24 million and $34 million, respectively, in other assets for its “ ” The Company has invested as a limited partner in various partnerships that collectively had total assets of approximately $1.2 billion at June 30, 2015 and December 31, 2014. Those partnerships generally construct or acquire properties for which the investing partners are eligible to receive certain federal income tax credits in accordance with government guidelines. Such investments may also provide tax deductible losses to the partners. The partnership investments also assist the Company in achieving its community reinvestment initiatives. As a limited partner, there is no recourse to the Company by creditors of the partnerships. However, the tax credits that result from the Company’s investments in such partnerships are generally subject to recapture should a partnership fail to comply with the respective government regulations. The Company’s maximum exposure to loss on its investments in such partnerships was $295 million, including $76 million of unfunded commitments, at June 30, 2015 and $243 million, including $56 million of unfunded commitments, at December 31, 2014. Contingent commitments to provide additional capital contributions to these partnerships were not material at June 30, 2015. The Company has not provided financial or NOTES TO FINANCIAL STATEMENTS, CONTINUED 11. Variable interest entities and asset securitizations, continued other support to the partnerships that was not contractually required. Management currently estimates that no material losses are probable as a result of the Company’s involvement with such entities. The Company, in its position as a limited partner, does not direct the activities that most significantly impact the economic performance of the partnerships and, therefore, in accordance with the accounting provisions for variable interest entities, the partnership entities are not included in the Company’s consolidated financial statements. As described in note 1, effective January 1, 2015 the Company retrospectively adopted for all periods presented amended accounting guidance on the accounting for investments in qualified affordable housing projects whereby the Company’s investment cost is amortized to income taxes in the consolidated statement of income as tax credits and other tax benefits resulting from deductible losses associated with the projects are received. The Company amortized $11 million and $21 million of its investments in qualified affordable housing projects to income tax expense during the three months and six months ended June 30, 2015, respectively, and recognized $15 million and $29 million of tax credits and other tax benefits during those respective periods. Similarly, for the three months and six months ended June 30, 2014, the Company amortized $14 million and $26 million, respectively, of its investments in qualified affordable housing projects to income tax expense, and recognized $18 million and $35 million of tax credits and other tax benefits during those respective periods.

Fair value measurements

Fair value measurements	6 Months Ended
	Jun. 30, 2015
Fair Value Disclosures [Abstract]
Fair value measurements	12. Fair value measurements GAAP permits an entity to choose to measure eligible financial instruments and other items at fair value. The Company has not made any fair value elections at June 30, 2015. Pursuant to GAAP, fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. A three-level hierarchy exists in GAAP for fair value measurements based upon the inputs to the valuation of an asset or liability. • Level 1 – Valuation is based on quoted prices in active markets for identical assets and liabilities. • Level 2 – Valuation is determined from quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar instruments in markets that are not active or by model-based techniques in which all significant inputs are observable in the market. • Level 3 – Valuation is derived from model-based and other techniques in which at least one significant input is unobservable and which may be based on the Company’s own estimates about the assumptions that market participants would use to value the asset or liability. When available, the Company attempts to use quoted market prices in active markets to determine fair value and classifies such items as Level 1 or Level 2. If quoted market prices in active markets are not available, fair value is often determined using model-based NOTES TO FINANCIAL STATEMENTS, CONTINUED 12. Fair value measurements, continued Trading account assets and liabilities Trading account assets and liabilities consist primarily of interest rate swap agreements and foreign exchange contracts with customers who require such services and offsetting positions with third parties to minimize the Company’s risk with respect to such transactions. The Company generally determines the fair value of its derivative trading account assets and liabilities using externally developed pricing models based on market observable inputs and, therefore, classifies such valuations as Level 2. Mutual funds held in connection with deferred compensation arrangements have been classified as Level 1 valuations. Valuations of investments in municipal and other bonds can generally be obtained through reference to quoted prices in less active markets for the same or similar securities or through model-based techniques in which all significant inputs are observable and, therefore, such valuations have been classified as Level 2. Investment securities available for sale The majority of the Company’s available-for-sale investment securities have been valued by reference to prices for similar securities or through model-based techniques in which all significant inputs are observable and, therefore, such valuations have been classified as Level 2. Certain investments in mutual funds and equity securities are actively traded and, therefore, have been classified as Level 1 valuations. Included in collateralized debt obligations are securities backed by trust preferred securities issued by financial institutions and other entities. The Company could not obtain pricing indications for many of these securities from its two primary independent pricing sources. The Company, therefore, performed internal modeling to estimate the cash flows and fair value of its portfolio of securities backed by trust preferred securities at June 30, 2015 and December 31, 2014. The modeling techniques included estimating cash flows using bond-specific assumptions about future collateral defaults and related loss severities. The resulting cash flows were then discounted by reference to market yields observed in the single-name trust preferred securities market. In determining a market yield applicable to the estimated cash flows, a margin over LIBOR ranging from 4% to 10%, with a weighted-average of 7%, was used. Significant unobservable inputs used in the determination of estimated fair value of collateralized debt obligations are included in the accompanying table of significant unobservable inputs to Level 3 measurements. At June 30, 2015, the total amortized cost and fair value of securities backed by trust preferred securities issued by financial institutions and other entities were $28 million and $50 million, respectively, and at December 31, 2014 were $30 million and $50 million, respectively. Securities backed by trust preferred securities issued by financial institutions and other entities constituted substantially all of the available-for-sale investment securities classified as Level 3 valuations. The Company ensures an appropriate control framework is in place over the valuation processes and techniques used for Level 3 fair value measurements. Internal pricing models used for significant valuation measurements have generally been subjected to validation procedures including review of mathematical constructs, valuation methodology and significant assumptions used. Real estate loans held for sale The Company utilizes commitments to sell real estate loans to hedge the exposure to changes in fair value of real estate loans held for sale. The carrying value of hedged real estate loans held for sale includes changes in estimated fair value during the hedge period. Typically, the Company attempts to hedge real estate loans held for sale from the date of close through the sale date. The fair value of hedged real estate loans held for sale is generally calculated by reference to quoted prices in secondary markets for commitments to sell real estate loans with similar characteristics and, accordingly, such loans have been classified as a Level 2 valuation. Commitments to originate real estate loans for sale and commitments to sell real estate loans The Company enters into various commitments to originate real estate loans for sale and commitments to sell real estate loans. Such commitments are considered to be derivative financial instruments and, therefore, are carried at estimated fair value on the consolidated balance sheet. The estimated fair values of such commitments were generally calculated by reference to quoted prices in secondary markets for commitments to sell real estate loans to certain government- sponsored entities and other parties. The fair valuations of commitments to sell real estate loans generally result in a Level 2 classification. The estimated fair value of commitments to originate real estate loans for sale are adjusted to reflect the Company’s anticipated commitment expirations. The estimated commitment expirations are considered significant unobservable inputs contributing to the Level 3 classification of commitments to originate real estate loans for sale. Significant unobservable inputs used in the determination of estimated fair value of commitments to originate real estate loans for sale are included in the accompanying table of significant unobservable inputs to Level 3 measurements. Interest rate swap agreements used for interest rate risk management The Company utilizes interest rate swap agreements as part of the management of interest rate risk to modify the repricing characteristics of certain portions of its portfolios of earning assets and interest-bearing liabilities. The Company generally determines the fair value of its interest rate swap agreements using externally developed pricing models based on market observable inputs and, therefore, classifies such valuations as Level 2. The Company has considered counterparty credit risk in the valuation of its interest rate swap agreement assets and has considered its own credit risk in the valuation of its interest rate swap agreement liabilities. The following tables present assets and liabilities at June 30, 2015 and December 31, 2014 measured at estimated fair value on a recurring basis: Fair value Level 1 (a) Level 2 (a) Level 3 (in thousands) Trading account assets $ 277,009 49,052 227,957 — Investment securities available for sale: U.S. Treasury and federal agencies 198,718 — 198,718 — Obligations of states and political subdivisions 7,504 — 7,504 — Mortgage-backed securities: Government issued or guaranteed 10,771,892 — 10,771,892 — Privately issued 88 — — 88 Collateralized debt obligations 50,483 — — 50,483 Other debt securities 121,954 — 121,954 — Equity securities 100,238 75,427 24,811 — 11,250,877 75,427 11,124,879 50,571 Real estate loans held for sale 798,404 — 798,404 — Other assets (b) 91,051 — 78,296 12,755 Total assets $ 12,417,341 124,479 12,229,536 63,326 Trading account liabilities $ 172,496 — 172,496 — Other liabilities (b) 4,074 — 2,525 1,549 Total liabilities $ 176,570 — 175,021 1,549 Fair value Level 1 (a) Level 2 (a) Level 3 (in thousands) Trading account assets $ 308,175 51,416 256,759 — Investment securities available for sale: U.S. Treasury and federal agencies 161,947 — 161,947 — Obligations of states and political subdivisions 8,198 — 8,198 — Mortgage-backed securities: Government issued or guaranteed 8,731,123 — 8,731,123 — Privately issued 103 — — 103 Collateralized debt obligations 50,316 — — 50,316 Other debt securities 121,488 — 121,488 — Equity securities 83,757 64,841 18,916 — 9,156,932 64,841 9,041,672 50,419 Real estate loans held for sale 742,249 — 742,249 — Other assets (b) 92,129 — 74,733 17,396 Total assets $ 10,299,485 116,257 10,115,413 67,815 Trading account liabilities $ 203,464 — 203,464 — Other liabilities (b) 8,596 — 8,547 49 Total liabilities $ 212,060 — 212,011 49 (a) There were no significant transfers between Level 1 and Level 2 of the fair value hierarchy during the six months ended June 30, 2015 and the year ended December 31, 2014. (b) Comprised predominantly of interest rate swap agreements used for interest rate risk management (Level 2), commitments to sell real estate loans (Level 2) and commitments to originate real estate loans to be held for sale (Level 3). The changes in Level 3 assets and liabilities measured at estimated fair value on a recurring basis during the three months ended June 30, 2015 were as follows: Investment securities available for sale Privately issued mortgage-backed Collateralized Other assets (in thousands) Balance – March 31, 2015 $ 95 $ 47,278 $ 26,230 Total gains realized/unrealized: Included in earnings — — 16,132 (a) Included in other comprehensive income — 7,629 (d) — Sales — — — Settlements (7 ) (4,424 ) — Transfers in and/or out of Level 3 (b) — — (31,156 )(c) Balance – June 30, 2015 $ 88 $ 50,483 $ 11,206 Changes in unrealized gains included in earnings related to assets still held at June 30, 2015 $ — $ — $ 6,330 (a) The changes in Level 3 assets and liabilities measured at estimated fair value on a recurring basis during the three months ended June 30, 2014 were as follows: Investment securities available for sale Privately issued mortgage-backed Collateralized Other assets (in thousands) Balance – March 31, 2014 $ 696 $ 61,768 $ 12,589 Total gains realized/unrealized: Included in earnings — — 31,517 (a) Included in other comprehensive income 205 (d) 4,486 (d) — Sales — — — Settlements (782 ) (10,054 ) — Transfers in and/or out of Level 3 (b) — — (22,083 )(c) Balance – June 30, 2014 $ 119 $ 56,200 $ 22,023 Changes in unrealized gains included in earnings related to assets still held at June 30, 2014 $ — $ — $ 20,215 (a) The changes in Level 3 assets and liabilities measured at estimated fair value on a recurring basis during the six months ended June 30, 2015 were as follows: Investment securities available for sale Privately issued mortgage-backed Collateralized Other assets (in thousands) Balance – January 1, 2015 $ 103 $ 50,316 $ 17,347 Total gains realized/unrealized: Included in earnings — — 45,902 (a) Included in other comprehensive income — 5,625 (d) — Settlements (15 ) (5,458 ) — Transfers in and/or out of Level 3 (b) — — (52,043 )(c) Balance – June 30, 2015 $ 88 $ 50,483 $ 11,206 Changes in unrealized gains included in earnings related to assets still held at June 30, 2015 $ — $ — $ 8,763 (a) The changes in Level 3 assets and liabilities measured at estimated fair value on a recurring basis during the six months ended June 30, 2014 were as follows: Investment securities available for sale Privately issued mortgage-backed Collateralized Other assets (in thousands) Balance – January 1, 2014 $ 1,850 $ 63,083 $ 3,941 Total gains realized/unrealized: Included in earnings — — 53,900 (a) Included in other comprehensive income 272 (d) 9,132 (d) — Settlements (2,003 ) (16,015 ) — Transfers in and/or out of Level 3 (b) — — (35,818 )(c) Balance – June 30, 2014 $ 119 $ 56,200 $ 22,023 Changes in unrealized gains included in earnings related to assets still held at June 30, 2014 $ — $ — $ 24,099 (a) (a) Reported as mortgage banking revenues in the consolidated statement of income and includes the fair value of commitment issuances and expirations. (b) The Company’s policy for transfers between fair value levels is to recognize the transfer as of the actual date of the event or change in circumstances that caused the transfer. (c) Transfers out of Level 3 consist of interest rate locks transferred to closed loans. (d) Reported as net unrealized gains (losses) on investment securities in the consolidated statement of comprehensive income. The Company is required, on a nonrecurring basis, to adjust the carrying value of certain assets or provide valuation allowances related to certain assets using fair value measurements. The more significant of those assets follow. Loans Loans are generally not recorded at fair value on a recurring basis. Periodically, the Company records nonrecurring adjustments to the carrying value of loans based on fair value measurements for partial charge-offs of the uncollectible portions of those loans. Nonrecurring adjustments also include certain impairment amounts for collateral-dependent loans when establishing the allowance for credit losses. Such amounts are generally based on the fair value of the underlying collateral supporting the loan and, as a result, the carrying value of the loan less the calculated valuation amount does not necessarily represent the fair value of the loan. Real estate collateral is typically valued using appraisals or other indications of value based on recent comparable sales of similar properties or assumptions generally observable in the marketplace and the related nonrecurring fair value measurement adjustments have generally been classified as Level 2, unless significant adjustments have been made to the valuation that are not readily observable by market participants. Non-real estate collateral supporting commercial loans generally consists of business assets such as receivables, inventory and equipment. Fair value estimations are typically determined by discounting recorded values of those assets to reflect estimated net realizable value considering specific borrower facts and circumstances and the experience of credit personnel in their dealings with similar borrower collateral liquidations. Such discounts were generally in the range of 10% to 90% at June 30, 2015. As these discounts are not readily observable and are considered significant, the valuations have been classified as Level 3. Loans subject to nonrecurring fair value measurement were $147 million at June 30, 2015 ($89 million and $58 million of which were classified as Level 2 and Level 3, respectively), $173 million at December 31, 2014 ($94 million and $79 million of which were classified as Level 2 and Level 3, respectively) and $212 million at June 30, 2014 ($129 million and $83 million of which were classified as Level 2 and Level 3, respectively). Changes in fair value recognized for partial charge-offs of loans and loan impairment reserves on loans held by the Company on June 30, 2015 were decreases of $34 million and $42 million for the three- and six-month periods ended June 30, 2015, respectively. Changes in fair value recognized for partial charge-offs of loans and loan impairment reserves on loans held by the Company on June 30, 2014 were decreases of $32 million and $47 million for the three- and six-month periods ended June 30, 2014, respectively. Assets taken in foreclosure of defaulted loans Assets taken in foreclosure of defaulted loans are primarily comprised of commercial and residential real property and are generally measured at the lower of cost or fair value less costs to sell. The fair value of the real property is generally determined using appraisals or other indications of value based on recent comparable sales of similar properties or assumptions generally observable in the marketplace, and the related nonrecurring fair value measurement adjustments have generally been classified as Level 2. Assets taken in foreclosure of defaulted loans subject to nonrecurring fair value measurement were $13 million and $15 million at June 30, 2015 and 2014, respectively. Changes in fair value recognized for those foreclosed assets held by the Company were not material during the three-month and six-month periods ended June 30, 2015 and 2014. Significant unobservable inputs to Level 3 measurements The following tables present quantitative information about the significant unobservable inputs used in the fair value measurements for Level 3 assets and liabilities at June 30, 2015 and December 31, 2014: Fair value at Valuation Unobservable Range (in thousands) Recurring fair value measurements Privately issued mortgage–backed securities $ 88 Two — — Collateralized debt obligations 50,483 Discounted Probability 12%-57% (37%) Loss severity 100% Net other assets (liabilities) (a) 11,206 Discounted Commitment 0%-95% (24%) Fair value at Valuation Unobservable Range (in thousands) Recurring fair value measurements Privately issued mortgage–backed securities $ 103 Two — — Collateralized debt obligations 50,316 Discounted Probability 12%-57% (36%) Loss severity 100% Net other assets (liabilities) (a) 17,347 Discounted Commitment 0%-96% (17%) (a) Other Level 3 assets (liabilities) consist of commitments to originate real estate loans. Sensitivity of fair value measurements to changes in unobservable inputs An increase (decrease) in the probability of default and loss severity for collateralized debt securities would generally result in a lower (higher) fair value measurement. An increase (decrease) in the estimate of expirations for commitments to originate real estate loans would generally result in a lower (higher) fair value measurement. Estimated commitment expirations are derived considering loan type, changes in interest rates and remaining length of time until closing. Disclosures of fair value of financial instruments The carrying amounts and estimated fair value for financial instrument assets (liabilities) are presented in the following table: June 30, 2015 Carrying Estimated Level 1 Level 2 Level 3 (in thousands) Financial assets: Cash and cash equivalents $ 1,350,858 $ 1,350,858 $ 1,291,501 $ 59,357 $ — Interest-bearing deposits at banks 4,045,852 4,045,852 — 4,045,852 — Trading account assets 277,009 277,009 49,052 227,957 — Investment securities 14,751,637 14,762,899 75,427 14,479,134 208,338 Loans and leases: Commercial loans and leases 20,111,028 19,822,748 — — 19,822,748 Commercial real estate loans 28,442,488 28,321,200 — 319,877 28,001,323 Residential real estate loans 8,444,542 8,465,046 — 5,024,771 3,440,275 Consumer loans 11,133,194 11,014,334 — — 11,014,334 Allowance for credit losses (929,987 ) — — — — Loans and leases, net 67,201,265 67,623,328 — 5,344,648 62,278,680 Accrued interest receivable 228,126 228,126 — 228,126 — Financial liabilities: Noninterest-bearing deposits $ (27,674,588 ) $ (27,674,588 ) $ — $ (27,674,588 ) $ — Savings deposits and NOW accounts (41,885,954 ) (41,885,954 ) — (41,885,954 ) — Time deposits (2,901,636 ) (2,921,070 ) — (2,921,070 ) — Deposits at Cayman Islands office (167,441 ) (167,441 ) — (167,441 ) — Short-term borrowings (153,299 ) (153,299 ) — (153,299 ) — Long-term borrowings (10,175,912 ) (10,219,668 ) — (10,219,668 ) — Accrued interest payable (72,062 ) (72,062 ) — (72,062 ) — Trading account liabilities (172,496 ) (172,496 ) — (172,496 ) — Other financial instruments: Commitments to originate real estate loans for sale $ 11,206 $ 11,206 $ — $ — $ 11,206 Commitments to sell real estate loans 12,270 12,270 — 12,270 — Other credit-related commitments (121,385 ) (121,385 ) — — (121,385 ) Interest rate swap agreements used for interest rate risk management 63,501 63,501 — 63,501 — December 31, 2014 Carrying Estimated Level 1 Level 2 Level 3 (in thousands) Financial assets: Cash and cash equivalents $ 1,373,357 $ 1,373,357 $ 1,296,923 $ 76,434 $ — Interest-bearing deposits at banks 6,470,867 6,470,867 — 6,470,867 — Trading account assets 308,175 308,175 51,416 256,759 — Investment securities 12,993,542 13,023,956 64,841 12,750,396 208,719 Loans and leases: Commercial loans and leases 19,461,292 19,188,574 — — 19,188,574 Commercial real estate loans 27,567,569 27,487,818 — 307,667 27,180,151 Residential real estate loans 8,657,301 8,729,056 — 5,189,086 3,539,970 Consumer loans 10,982,794 10,909,623 — — 10,909,623 Allowance for credit losses (919,562 ) — — — — Loans and leases, net 65,749,394 66,315,071 — 5,496,753 60,818,318 Accrued interest receivable 227,348 227,348 — 227,348 — Financial liabilities: Noninterest-bearing deposits $ (26,947,880 ) $ (26,947,880 ) $ — $ (26,947,880 ) $ — Savings deposits and NOW accounts (43,393,618 ) (43,393,618 ) — (43,393,618 ) — Time deposits (3,063,973 ) (3,086,126 ) — (3,086,126 ) — Deposits at Cayman Islands office (176,582 ) (176,582 ) — (176,582 ) — Short-term borrowings (192,676 ) (192,676 ) — (192,676 ) — Long-term borrowings (9,006,959 ) (9,139,789 ) — (9,139,789 ) — Accrued interest payable (63,372 ) (63,372 ) — (63,372 ) — Trading account liabilities (203,464 ) (203,464 ) — (203,464 ) — Other financial instruments: Commitments to originate real estate loans for sale $ 17,347 $ 17,347 $ — $ — $ 17,347 Commitments to sell real estate loans (7,065 ) (7,065 ) — (7,065 ) — Other credit-related commitments (119,079 ) (119,079 ) — — (119,079 ) Interest rate swap agreements used for interest rate risk management 73,251 73,251 — 73,251 — With the exception of marketable securities, certain off-balance sheet financial instruments and one-to-four family residential real estate loans originated for sale, the Company’s financial instruments are not readily marketable and market prices do not exist. The Company, in attempting to comply with the provisions of GAAP that require disclosures of fair value of financial instruments, has not attempted to market its financial instruments to potential buyers, if any exist. Since negotiated prices in illiquid markets depend greatly upon the then present motivations of the buyer and seller, it is reasonable to assume that actual sales prices could vary widely from any estimate of fair value made without the benefit of negotiations. Additionally, changes in market interest rates can dramatically impact the value of financial instruments in a short period of time. The following assumptions, methods and calculations were used in determining the estimated fair value of financial instruments not measured at fair value in the consolidated balance sheet. Cash and cash equivalents, interest-bearing deposits at banks, deposits at Cayman Islands office, short-term borrowings, accrued interest receivable and accrued interest payable Due to the nature of cash and cash equivalents and the near maturity of interest-bearing deposits at banks, deposits at Cayman Islands office, short-term borrowings, accrued interest receivable and accrued interest payable, the Company estimated that the carrying amount of such instruments approximated estimated fair value. Investment securities Estimated fair values of investments in readily marketable securities were generally based on quoted market prices. Investment securities that were not readily marketable were assigned amounts based on estimates provided by outside parties or modeling techniques that relied upon discounted calculations of projected cash flows or, in the case of other investment securities, which include capital stock of the Federal Reserve Bank of New York and the Federal Home Loan Bank of New York, at an amount equal to the carrying amount. Loans and leases In general, discount rates used to calculate values for loan products were based on the Company’s pricing at the respective period end. A higher discount rate was assumed with respect to estimated cash flows associated with nonaccrual loans. Projected loan cash flows were adjusted for estimated credit losses. However, such estimates made by the Company may not be indicative of assumptions and adjustments that a purchaser of the Company’s loans and leases would seek. Deposits Pursuant to GAAP, the estimated fair value ascribed to noninterest-bearing deposits, savings deposits and NOW accounts must be established at carrying value because of the customers’ ability to withdraw funds immediately. Time deposit accounts are required to be revalued based upon prevailing market interest rates for similar maturity instruments. As a result, amounts assigned to time deposits were based on discounted cash flow calculations using prevailing market interest rates based on the Company’s pricing at the respective date for deposits with comparable remaining terms to maturity. The Company believes that deposit accounts have a value greater than that prescribed by GAAP. The Company feels, however, that the value associated with these deposits is greatly influenced by characteristics of the buyer, such as the ability to reduce the costs of servicing the deposits and deposit attrition which often occurs following an acquisition. Long-term borrowings The amounts assigned to long-term borrowings were based on quoted market prices, when available, or were based on discounted cash flow calculations using prevailing market interest rates for borrowings of similar terms and credit risk. Other commitments and contingencies As described in note 13, in the normal course of business, various commitments and contingent liabilities are outstanding, such as loan commitments, credit guarantees and letters of credit. The Company’s pricing of such financial instruments is based largely on credit quality and relationship, probability of funding and other requirements. Loan commitments often have fixed expiration dates and contain termination and other clauses which provide for relief from funding in the event of significant deterioration in the credit quality of the customer. The rates and terms of the Company’s loan commitments, credit guarantees and letters of credit are competitive with other financial institutions operating in markets served by the Company. The Company believes that the carrying amounts, which are included in other liabilities, are reasonable estimates of the fair value of these financial instruments. The Company does not believe that the estimated information presented herein is representative of the earnings power or value of the Company. The preceding analysis, which is inherently limited in depicting fair value, also does not consider any value associated with existing customer relationships nor the ability of the Company to create value through loan origination, deposit gathering or fee generating activities. Many of the estimates presented herein are based upon the use of highly subjective information and assumptions and, accordingly, the results may not be precise. Management believes that fair value estimates may not be comparable between financial institutions due to the wide range of permitted valuation techniques and numerous estimates which must be made. Furthermore, because the disclosed fair value amounts were estimated as of the balance sheet date, the amounts actually realized or paid upon maturity or settlement of the various financial instruments could be significantly different.

Commitments and contingencies

Commitments and contingencies	6 Months Ended
	Jun. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and contingencies	13. Commitments and contingencies In the normal course of business, various commitments and contingent liabilities are outstanding. The following table presents the Company’s significant commitments. Certain of these commitments are not included in the Company’s consolidated balance sheet. June 30, December 31, (in thousands) Commitments to extend credit Home equity lines of credit $ 5,612,243 6,194,516 Commercial real estate loans to be sold 104,832 212,257 Other commercial real estate and construction 5,601,820 4,834,699 Residential real estate loans to be sold 671,670 432,352 Other residential real estate 719,788 524,399 Commercial and other 11,439,086 11,080,856 Standby letters of credit 3,531,401 3,706,888 Commercial letters of credit 42,858 46,965 Financial guarantees and indemnification contracts 2,795,007 2,490,050 Commitments to sell real estate loans 1,354,654 1,237,294 Commitments to extend credit are agreements to lend to customers, generally having fixed expiration dates or other termination clauses that may require payment of a fee. Standby and commercial letters of credit are conditional commitments issued to guarantee the performance of a customer to a third party. Standby letters of credit generally are contingent upon the failure of the customer to perform according to the terms of the underlying contract with the third party, whereas commercial letters of credit are issued to facilitate commerce and typically result in the commitment being funded when the underlying transaction is consummated between the customer and a third party. The credit risk associated with commitments to extend credit and standby and commercial letters of credit is essentially the same as that involved with extending loans to customers and is subject to normal credit policies. Collateral may be obtained based on management’s assessment of the customer’s creditworthiness. Financial guarantees and indemnification contracts are oftentimes similar to standby letters of credit and include mandatory purchase agreements issued to ensure that customer obligations are fulfilled, recourse obligations associated with sold loans, and other guarantees of customer performance or compliance with designated rules and regulations. Included in financial guarantees and indemnification contracts are loan principal amounts sold with recourse in conjunction with the Company’s involvement in the Fannie Mae Delegated Underwriting and Servicing program. The Company’s maximum credit risk for recourse associated with loans sold under this program totaled approximately $2.5 billion and $2.4 billion at June 30, 2015 and December 31, 2014, respectively. Since many loan commitments, standby letters of credit, and guarantees and indemnification contracts expire without being funded in whole or in part, the contract amounts are not necessarily indicative of future cash flows. The Company utilizes commitments to sell real estate loans to hedge exposure to changes in the fair value of real estate loans held for sale. Such commitments are considered derivatives and along with commitments to originate real estate loans to be held for sale are generally recorded in the consolidated balance sheet at estimated fair market value. The Company also has commitments under long-term operating leases. The Company is contractually obligated to repurchase previously sold residential real estate loans that do not ultimately meet investor sale criteria related to underwriting procedures or loan documentation. When required to do so, the Company may reimburse loan purchasers for losses incurred or may repurchase certain loans. The Company reduces residential mortgage banking revenues by an estimate for losses related to its obligations to loan purchasers. The amount of those charges is based on the volume of loans sold, the level of reimbursement requests received from loan purchasers and estimates of losses that may be associated with previously sold loans. Subject to the outcome of the matter discussed in the following paragraph, at June 30, 2015, management believes that any further liability arising out of the Company’s obligation to loan purchasers is not material to the Company’s consolidated financial position. The Company is the subject of an investigation by government agencies relating to the origination of Federal Housing Administration (“FHA”) insured residential home loans and residential home loans sold to The Federal Home Loan Mortgage Corporation (“Freddie Mac”) and The Federal National Mortgage Association (“Fannie Mae”). A number of other U.S. financial institutions have announced similar investigations. Regarding FHA loans, the U.S. Department of Housing and Urban Development (“HUD”) Office of Inspector General and the U.S. Department of Justice (collectively, the “Government”) are investigating whether the Company complied with underwriting guidelines concerning certain loans where HUD paid FHA insurance claims. The Company is fully cooperating with the investigation. The Government has advised the Company that based upon its review of a sample of loans for which an FHA insurance claim was paid by HUD, some of the loans do not meet underwriting guidelines. The Company, based on its own review of the sample, does not agree with the sampling methodology and loan analysis employed by the Government. Regarding loans originated by the Company and sold to Freddie Mac and Fannie Mae, the investigation concerns whether the mortgages sold to Freddie Mac and Fannie Mae comply with applicable underwriting guidelines. The Company is also cooperating with that portion of the investigation. The investigation could lead to claims by the Government under the False Claims Act and the Financial Institutions Reform, Recovery, and Enforcement Act of 1989, which allow treble and other special damages substantially in excess of actual losses. Remedies in these proceedings or settlements may include restitution, fines, penalties, or alterations in the Company’s business practices. The Company and the Government have begun settlement discussions regarding the investigation. M&T and its subsidiaries are subject in the normal course of business to various pending and threatened legal proceedings in which claims for monetary damages are asserted. On an on-going basis management, after consultation with legal counsel, assesses the Company’s liabilities and contingencies in connection with such legal proceedings. For those matters where it is probable that the Company will incur losses and the amounts of the losses can be reasonably estimated, the Company records an expense and corresponding liability in its consolidated financial statements. To the extent the pending or threatened litigation could result in exposure in excess of that liability, the amount of such excess is not currently estimable. Although not considered probable, the range of reasonably possible losses for such matters in the aggregate, beyond the existing recorded liability, was between $0 and $40 million. Although the Company does not believe that the outcome of pending litigations will be material to the Company’s consolidated financial position, it cannot rule out the possibility that such outcomes will be material to the consolidated results of operations for a particular reporting period in the future.

Segment information

Segment information	6 Months Ended
	Jun. 30, 2015
Segment Reporting [Abstract]
Segment information	14. Segment information Reportable segments have been determined based upon the Company’s internal profitability reporting system, which is organized by strategic business unit. Certain strategic business units have been combined for segment information reporting purposes where the nature of the products and services, the type of customer and the distribution of those products and services are similar. The reportable segments are Business Banking, Commercial Banking, Commercial Real Estate, Discretionary Portfolio, Residential Mortgage Banking and Retail Banking. The financial information of the Company’s segments was compiled utilizing the accounting policies described in note 22 to the Company’s consolidated financial statements as of and for the year ended December 31, 2014. The management accounting policies and processes utilized in compiling segment financial information are highly subjective and, unlike financial accounting, are not based on authoritative guidance similar to GAAP. As a result, the financial information of the reported segments is not necessarily comparable with similar information reported by other financial institutions. Furthermore, changes in management structure or allocation methodologies and procedures may result in changes in reported segment financial data. Effective January 1, 2015, the Company made certain changes to its methodology for measuring segment profit and loss. Those changes in the measurement of segment profitability were largely the result of updated funds transfer pricing and various cost allocation reviews. The most significant changes to the funds transfer pricing resulted from ascribing a longer duration to non-maturity deposits, which significantly benefitted the Retail Banking segment. The cost allocation review having the largest impact related to a branch cost study. That study consisted of transaction reviews and time studies which resulted in a higher cost allocation from the Retail Banking segment to the Business Banking segment. As a result of the changes, prior period financial information has been restated to provide segment information on a comparable basis, as noted in the following tables. Three months ended June 30, 2014 Net income (loss) as Impact of Net income (loss) (in thousands) Business Banking $ 27,760 (4,008 ) 23,752 Commercial Banking 105,358 (1,267 ) 104,091 Commercial Real Estate 77,526 (1,798 ) 75,728 Discretionary Portfolio 14,980 63 15,043 Residential Mortgage Banking 27,712 (1,063 ) 26,649 Retail Banking 32,034 40,939 72,973 All Other (1,034 ) (32,866 ) (33,900 ) Total $ 284,336 — 284,336 Six months ended June 30, 2014 Net income (loss) as Impact of Net income (loss) (in thousands) Business Banking $ 56,358 (7,633 ) 48,725 Commercial Banking 205,123 (2,191 ) 202,932 Commercial Real Estate 152,087 (3,807 ) 148,280 Discretionary Portfolio 26,259 144 26,403 Residential Mortgage Banking 47,123 (1,894 ) 45,229 Retail Banking 61,745 80,262 142,007 All Other (35,342 ) (64,881 ) (100,223 ) Total $ 513,353 — 513,353 As also described in note 22 to the Company’s 2014 consolidated financial statements, neither goodwill nor core deposit and other intangible assets (and the amortization charges associated with such assets) resulting from acquisitions of financial institutions have been allocated to the Company’s reportable segments, but are included in the “All Other” category. The Company does, however, assign such intangible assets to business units for purposes of testing for impairment. Information about the Company’s segments is presented in the following table: Three months ended June 30 2015 2014 Total Inter- Net Total Inter- Net (in thousands) Business Banking $ 111,131 1,122 25,354 112,734 1,220 23,752 Commercial Banking 257,257 1,099 108,081 252,347 1,356 104,091 Commercial Real Estate 178,949 427 79,751 164,262 525 75,728 Discretionary Portfolio 20,477 (5,376 ) 10,756 29,912 (5,282 ) 15,043 Residential Mortgage Banking 112,029 12,436 27,699 109,837 11,772 26,649 Retail Banking 305,573 3,259 68,806 311,554 3,897 72,973 All Other 194,739 (12,967 ) (33,759 ) 144,880 (13,488 ) (33,900 ) Total $ 1,180,155 — 286,688 1,125,526 — 284,336 Six months ended June 30 2015 2014 Total Inter- Net Total Inter- Net (in thousands) Business Banking $ 219,691 2,167 50,165 224,504 2,277 48,725 Commercial Banking 503,838 2,184 204,504 501,696 2,553 202,932 Commercial Real Estate 342,269 509 159,837 321,585 873 148,280 Discretionary Portfolio 35,951 (10,819 ) 16,710 54,569 (10,321 ) 26,403 Residential Mortgage Banking 223,487 23,823 59,664 203,602 21,520 45,229 Retail Banking 605,964 6,396 137,694 618,334 7,402 142,007 All Other 348,746 (24,260 ) (100,273 ) 277,776 (24,304 ) (100,223 ) Total $ 2,279,946 — 528,301 2,202,066 — 513,353 Average total assets Six months ended June 30 Year ended December 31 2015 2014 2014 (in millions) Business Banking $ 5,313 5,286 5,281 Commercial Banking 23,997 22,742 22,892 Commercial Real Estate 18,191 16,878 17,113 Discretionary Portfolio 23,029 19,417 20,798 Residential Mortgage Banking 3,413 3,226 3,333 Retail Banking 10,830 10,229 10,449 All Other 11,977 10,500 12,277 Total $ 96,750 88,278 92,143 (a) Total revenues are comprised of net interest income and other income. Net interest income is the difference between taxable-equivalent interest earned on assets and interest paid on liabilities owed by a segment and a funding charge (credit) based on the Company ’ s internal funds transfer pricing and allocation methodology. Segments are charged a cost to fund any assets (e.g. loans) and are paid a funding credit for any funds provided (e.g. deposits). The taxable-equivalent adjustment aggregated $6,020,000 and $5,849,000 for the three-month periods ended June 30, 2015 and 2014, respectively, and $11,858,000 and $11,794,000 for the six-month periods ended June 30, 2015 and 2014, respectively, and is eliminated in “ All Other ” total revenues. Intersegment revenues are included in total revenues of the reportable segments. The elimination of intersegment revenues is included in the determination of “ All Other ” total revenues.

Relationship with Bayview Lendi

Relationship with Bayview Lending Group LLC and Bayview Financial Holdings, L.P.	6 Months Ended
	Jun. 30, 2015
Text Block [Abstract]
Relationship with Bayview Lending Group LLC and Bayview Financial Holdings, L.P.	15. Relationship with Bayview Lending Group LLC and Bayview Financial Holdings, L.P. M&T holds a 20% minority interest in Bayview Lending Group LLC (“BLG”), a privately-held commercial mortgage company. M&T recognizes income or loss from BLG using the equity method of accounting. The carrying value of that investment was $38 million at June 30, 2015. Bayview Financial Holdings, L.P. (together with its affiliates, “Bayview Financial”), a privately-held specialty mortgage finance company, is BLG’s majority investor. In addition to their common investment in BLG, the Company and Bayview Financial conduct other business activities with each other. The Company has obtained loan servicing rights for mortgage loans from BLG and Bayview Financial having outstanding principal balances of $4.5 billion and $4.8 billion at June 30, 2015 and December 31, 2014, respectively. Revenues from those servicing rights were $6 million and $7 million during the three months ended June 30, 2015 and 2014, respectively, and $12 million and $14 million for the six months ended June 30, 2015 and June 30, 2014, respectively. The Company sub-services residential mortgage loans for Bayview Financial having outstanding principal balances totaling $41.5 billion and $41.3 billion at June 30, 2015 and December 31, 2014, respectively. Revenues earned for sub-servicing loans for Bayview Financial were $30 million and $27 million for the three-month periods ended June 30, 2015 and 2014, respectively, and $65 million and $53 million for the six-month periods ended June 30, 2015 and 2014, respectively. In addition, the Company held $192 million and $202 million of mortgage-backed securities in its held-to-maturity portfolio at June 30, 2015 and December 31, 2014, respectively, that were securitized by Bayview Financial.

Sale of trust accounts

Sale of trust accounts	6 Months Ended
	Jun. 30, 2015
Discontinued Operations and Disposal Groups [Abstract]
Sale of trust accounts	16. Sale of trust accounts In April 2015, the Company sold the trade processing business within the retirement services division of its Institutional Client Services business. That sale resulted in an after-tax gain of $23 million ($45 million pre-tax) that reflected the allocation of approximately $11 million of previously recorded goodwill to the divested business. Revenues of the sold business had been included in “trust income” and were $9 million during the three months ended March 31, 2015; $10 million and $18 million during the three months and six months ended June 30, 2014, respectively; and $34 million during the year ended December 31, 2014. After considering related expenses, net income attributable to the business that was sold was not material to the consolidated results of operations of the Company in any of those periods.

Significant accounting polici25

Significant accounting policies (Policies)	6 Months Ended
	Jun. 30, 2015
Accounting Policies [Abstract]
Consolidation	The consolidated financial statements of M&T Bank Corporation (“M&T”) and subsidiaries (“the Company”) were compiled in accordance with generally accepted accounting principles (“GAAP”) using the accounting policies set forth in note 1 of Notes to Financial Statements included in the 2014 Annual Report. Additionally, effective January 1, 2015 the Company made an accounting policy election in accordance with amended accounting guidance issued by the Financial Accounting Standards Board in January 2014 to account for investments in qualified affordable housing projects using the proportional amortization method. Under the proportional amortization method, the Company amortizes the initial cost of the investment in proportion to the tax credits and other tax benefits received and recognizes the net investment performance in the income statement as a component of income tax expense. The adoption of the amended guidance did not have a significant effect on the Company’s financial position or results of operations, but did result in the restatement of the consolidated statement of income for the three months and six months ended June 30, 2014 to remove $14 million and $26 million, respectively, of losses associated with qualified affordable housing projects from “other costs of operations” and include the amortization of the initial cost of the investment in income tax expense. The cumulative effect adjustment associated with adopting the amended guidance was not material as of the beginning of any period presented in these consolidated financial statements. See note 11 for information regarding the Company’s investments in qualified affordable housing projects. In the opinion of management, all adjustments necessary for a fair presentation have been made and, except as described above, were all of a normal recurring nature.

Investment securities (Tables)

Investment securities (Tables)	6 Months Ended
	Jun. 30, 2015
Investments, Debt and Equity Securities [Abstract]
Amortized Cost and Estimated Fair Value of Investment Securities	The amortized cost and estimated fair value of investment securities were as follows: Amortized Gross Gross Estimated (in thousands) June 30, 2015 Investment securities available for sale: U.S. Treasury and federal agencies $ 197,315 1,404 1 $ 198,718 Obligations of states and political subdivisions 7,387 169 52 7,504 Mortgage-backed securities: Government issued or guaranteed 10,637,736 174,277 40,121 10,771,892 Privately issued 89 2 3 88 Collateralized debt obligations 28,381 22,518 416 50,483 Other debt securities 138,525 1,672 18,243 121,954 Equity securities 83,660 16,777 199 100,238 11,093,093 216,819 59,035 11,250,877 Investment securities held to maturity: Obligations of states and political subdivisions 136,922 1,584 391 138,115 Mortgage-backed securities: Government issued or guaranteed 2,828,638 54,355 10,143 2,872,850 Privately issued 191,910 1,868 36,011 157,767 Other debt securities 7,115 — — 7,115 3,164,585 57,807 46,545 3,175,847 Other securities 336,175 — — 336,175 Total $ 14,593,853 274,626 105,580 $ 14,762,899 December 31, 2014 Investment securities available for sale: U.S. Treasury and federal agencies $ 161,408 544 5 $ 161,947 Obligations of states and political subdivisions 8,027 224 53 8,198 Mortgage-backed securities: Government issued or guaranteed 8,507,571 223,889 337 8,731,123 Privately issued 104 2 3 103 Collateralized debt obligations 30,073 21,276 1,033 50,316 Other debt securities 138,240 1,896 18,648 121,488 Equity securities 73,901 11,020 1,164 83,757 8,919,324 258,851 21,243 9,156,932 Investment securities held to maturity: Obligations of states and political subdivisions 148,961 2,551 189 151,323 Mortgage-backed securities: Government issued or guaranteed 3,149,320 78,485 7,000 3,220,805 Privately issued 201,733 1,143 44,576 158,300 Other debt securities 7,854 — — 7,854 3,507,868 82,179 51,765 3,538,282 Other securities 328,742 — — 328,742 Total $ 12,755,934 341,030 73,008 $ 13,023,956
Amortized Cost and Estimated Fair Value of Debt Securities by Contractual Maturity	At June 30, 2015, the amortized cost and estimated fair value of debt securities by contractual maturity were as follows: Amortized Estimated (in thousands) Debt securities available for sale: Due in one year or less $ 10,418 10,461 Due after one year through five years 197,809 199,557 Due after five years through ten years 2,619 2,637 Due after ten years 160,762 166,004 371,608 378,659 Mortgage-backed securities available for sale 10,637,825 10,771,980 $ 11,009,433 11,150,639 Debt securities held to maturity: Due in one year or less $ 28,570 28,738 Due after one year through five years 83,513 84,258 Due after five years through ten years 24,839 25,119 Due after ten years 7,115 7,115 144,037 145,230 Mortgage-backed securities held to maturity 3,020,548 3,030,617 $ 3,164,585 3,175,847
Investment Securities in Continuous Unrealized Loss Position	A summary of investment securities that as of June 30, 2015 and December 31, 2014 had been in a continuous unrealized loss position for less than twelve months and those that had been in a continuous unrealized loss position for twelve months or longer follows: Less than 12 months 12 months or more Fair value Unrealized Fair value Unrealized (in thousands) June 30, 2015 Investment securities available for sale: U.S. Treasury and federal agencies $ 1,750 (1 ) — — Obligations of states and political subdivisions 1,403 (7 ) 1,527 (45 ) Mortgage-backed securities: Government issued or guaranteed 2,688,635 (39,970 ) 6,231 (151 ) Privately issued 15 — 53 (3 ) Collateralized debt obligations — — 2,444 (416 ) Other debt securities 13,142 (185 ) 93,061 (18,058 ) Equity securities — — 226 (199 ) 2,704,945 (40,163 ) 103,542 (18,872 ) Investment securities held to maturity: Obligations of states and political subdivisions 38,431 (360 ) 2,289 (31 ) Mortgage-backed securities: Government issued or guaranteed 383,167 (2,693 ) 249,870 (7,450 ) Privately issued — — 127,482 (36,011 ) 421,598 (3,053 ) 379,641 (43,492 ) Total $ 3,126,543 (43,216 ) 483,183 (62,364 ) December 31, 2014 Investment securities available for sale: U.S. Treasury and federal agencies $ 6,505 (5 ) — — Obligations of states and political subdivisions 1,785 (52 ) 121 (1 ) Mortgage-backed securities: Government issued or guaranteed 39,001 (186 ) 5,555 (151 ) Privately issued — — 65 (3 ) Collateralized debt obligations 2,108 (696 ) 5,512 (337 ) Other debt securities 14,017 (556 ) 92,661 (18,092 ) Equity securities 2,138 (1,164 ) — — 65,554 (2,659 ) 103,914 (18,584 ) Investment securities held to maturity: Obligations of states and political subdivisions 29,886 (184 ) 268 (5 ) Mortgage-backed securities: Government issued or guaranteed 137,413 (361 ) 446,780 (6,639 ) Privately issued — — 127,512 (44,576 ) 167,299 (545 ) 574,560 (51,220 ) Total $ 232,853 (3,204 ) 678,474 (69,804 )

Loans and leases and the allo27

Loans and leases and the allowance for credit losses (Tables)	6 Months Ended
	Jun. 30, 2015
Receivables [Abstract]
Outstanding Principal Balance and Carrying Amount of Loans that is Included in Consolidated Balance Sheet	The outstanding principal balance and the carrying amount of acquired loans that were recorded at fair value at the acquisition date and included in the consolidated balance sheet follow: June 30, December 31, (in thousands) Outstanding principal balance $ 2,631,165 3,070,268 Carrying amount: Commercial, financial, leasing, etc. 191,721 247,820 Commercial real estate 775,816 961,828 Residential real estate 407,774 453,360 Consumer 844,068 933,537 $ 2,219,379 2,596,545
Summary of Changes in Accretable Yield for Acquired Loans	A summary of changes in the accretable yield for acquired loans for the three months and six months ended June 30, 2015 and 2014 follows: Three months ended June 30 2015 2014 Purchased Other Purchased Other (in thousands) Balance at beginning of period $ 71,422 357,895 $ 30,939 485,162 Interest income (5,772 ) (40,024 ) (5,106 ) (43,452 ) Reclassifications from nonaccretable balance, net 11,974 26,840 249 774 Other (a) — 278 — 8,486 Balance at end of period $ 77,624 344,989 $ 26,082 450,970 Six months ended June 30 2015 2014 Purchased Other Purchased Other (in thousands) Balance at beginning of period $ 76,518 397,379 $ 37,230 538,633 Interest income (10,978 ) (81,301 ) (11,434 ) (96,085 ) Reclassifications from nonaccretable balance, net 12,084 27,023 286 774 Other (a) — 1,888 — 7,648 Balance at end of period $ 77,624 344,989 $ 26,082 450,970 (a) Other changes in expected cash flows including changes in interest rates and prepayment assumptions.
Summary of Current, Past Due and Nonaccrual Loans	A summary of current, past due and nonaccrual loans as of June 30, 2015 and December 31, 2014 follows: Current 30-89 90 Days or Purchased Nonaccrual Total Non- Acquired (in thousands) June 30, 2015 Commercial, financial, leasing, etc. $ 19,852,368 36,637 4,777 1,628 5,273 210,345 $ 20,111,028 Real estate: Commercial 22,487,721 156,567 17,079 17,919 52,115 167,520 22,898,921 Residential builder and developer 1,666,183 4,233 — 6,603 73,628 56,854 1,807,501 Other commercial construction 3,642,229 43,683 6,112 2,834 20,059 21,149 3,736,066 Residential 7,525,761 197,893 207,195 18,972 15,804 164,721 8,130,346 Residential Alt-A 234,859 11,152 — — — 68,185 314,196 Consumer: Home equity lines and loans 5,765,082 31,446 — 12,371 2,361 78,250 5,889,510 Automobile 2,134,000 29,906 — — — 15,156 2,179,062 Other 2,996,396 31,591 3,405 18,264 — 14,966 3,064,622 Total $ 66,304,599 543,108 238,568 78,591 169,240 797,146 $ 68,131,252 4. Loans and leases and the allowance for credit losses, continued Current 30-89 90 Days or Purchased Nonaccrual Total Non- Acquired (in thousands) December 31, 2014 Commercial, financial, leasing, etc. $ 19,228,265 37,246 1,805 6,231 10,300 177,445 $ 19,461,292 Real estate: Commercial 22,208,491 118,704 22,170 14,662 51,312 141,600 22,556,939 Residential builder and developer 1,273,607 11,827 492 9,350 98,347 71,517 1,465,140 Other commercial construction 3,484,932 17,678 — — 17,181 25,699 3,545,490 Residential 7,640,368 226,932 216,489 35,726 18,223 180,275 8,318,013 Residential Alt-A 249,810 11,774 — — — 77,704 339,288 Consumer: Home equity lines and loans 5,859,378 42,945 — 27,896 2,374 89,291 6,021,884 Automobile 1,931,138 30,500 — 133 — 17,578 1,979,349 Other 2,909,791 33,295 4,064 16,369 — 18,042 2,981,561 Total $ 64,785,780 530,901 245,020 110,367 197,737 799,151 $ 66,668,956 (a) Acquired loans that were recorded at fair value at acquisition date. This category does not include purchased impaired loans that are presented separately. (b) Accruing loans that were impaired at acquisition date and were recorded at fair value.
Changes in Allowance for Credit Losses	Changes in the allowance for credit losses for the three months ended June 30, 2015 were as follows: Commercial, Real Estate Commercial Residential Consumer Unallocated Total (in thousands) Beginning balance $ 281,069 317,375 60,741 186,052 76,136 $ 921,373 Provision for credit losses 9,737 (3,652 ) 1,624 21,016 1,275 30,000 Net charge-offs Charge-offs (7,728 ) (3,470 ) (3,309 ) (18,455 ) — (32,962 ) Recoveries 3,672 1,041 1,238 5,625 — 11,576 Net charge-offs (4,056 ) (2,429 ) (2,071 ) (12,830 ) — (21,386 ) Ending balance $ 286,750 311,294 60,294 194,238 77,411 $ 929,987 Changes in the allowance for credit losses for the three months ended June 30, 2014 were as follows: Commercial, Real Estate Commercial Residential Consumer Unallocated Total (in thousands) Beginning balance $ 276,835 324,805 77,062 162,134 75,932 $ 916,768 Provision for credit losses 25,556 (12,229 ) (1,957 ) 18,676 (46 ) 30,000 Net charge-offs Charge-offs (14,142 ) (2,814 ) (5,478 ) (19,404 ) — (41,838 ) Recoveries 4,002 1,492 2,777 4,465 — 12,736 Net charge-offs (10,140 ) (1,322 ) (2,701 ) (14,939 ) — (29,102 ) Ending balance $ 292,251 311,254 72,404 165,871 75,886 $ 917,666 Changes in the allowance for credit losses for the six months ended June 30, 2015 were as follows: Commercial, Real Estate 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 11,179 11,890 2,584 40,590 1,757 68,000 Net charge-offs Charge-offs (20,078 ) (10,149 ) (6,427 ) (43,784 ) — (80,438 ) Recoveries 7,611 1,626 2,227 11,399 — 22,863 Net charge-offs (12,467 ) (8,523 ) (4,200 ) (32,385 ) — (57,575 ) Ending balance $ 286,750 311,294 60,294 194,238 77,411 $ 929,987 Changes in the allowance for credit losses for the six months ended June 30, 2014 were as follows: Commercial, Real Estate Commercial Residential Consumer Unallocated Total (in thousands) Beginning balance $ 273,383 324,978 78,656 164,644 75,015 $ 916,676 Provision for credit losses 38,154 (12,113 ) 2,271 32,817 871 62,000 Net charge-offs Charge-offs (28,951 ) (6,300 ) (12,931 ) (41,095 ) — (89,277 ) Recoveries 9,665 4,689 4,408 9,505 — 28,267 Net charge-offs (19,286 ) (1,611 ) (8,523 ) (31,590 ) — (61,010 ) Ending balance $ 292,251 311,254 72,404 165,871 75,886 $ 917,666
Impaired Loans and Leases	The following tables provide information with respect to loans and leases that were considered impaired as of June 30, 2015 and December 31, 2014 and for the three-month and six-month periods ended June 30, 2015 and June 30, 2014: June 30, 2015 December 31, 2014 Recorded Unpaid Related Recorded Unpaid Related (in thousands) With an allowance recorded: Commercial, financial, leasing, etc. $ 122,574 147,028 31,098 132,340 165,146 31,779 Real estate: Commercial 105,064 120,905 18,390 83,955 96,209 14,121 Residential builder and developer 7,808 10,439 661 17,632 22,044 805 Other commercial construction 3,091 4,542 514 5,480 6,484 900 Residential 84,241 102,237 4,931 88,970 107,343 4,296 Residential Alt-A 94,752 107,894 10,000 101,137 114,565 11,000 Consumer: Home equity lines and loans 21,235 22,219 3,531 19,771 20,806 6,213 Automobile 25,175 25,175 6,334 30,317 30,317 8,070 Other 19,256 19,256 5,458 18,973 18,973 5,459 483,196 559,695 80,917 498,575 581,887 82,643 With no related allowance recorded: Commercial, financial, leasing, etc. 116,982 138,635 — 73,978 81,493 — Real estate: Commercial 72,094 79,541 — 66,777 78,943 — Residential builder and developer 53,843 94,700 — 58,820 96,722 — Other commercial construction 18,524 39,347 — 20,738 41,035 — Residential 16,174 26,120 — 16,815 26,750 — Residential Alt-A 23,535 40,517 — 26,752 46,964 — 301,152 418,860 — 263,880 371,907 — Total: Commercial, financial, leasing, etc. 239,556 285,663 31,098 206,318 246,639 31,779 Real estate: Commercial 177,158 200,446 18,390 150,732 175,152 14,121 Residential builder and developer 61,651 105,139 661 76,452 118,766 805 Other commercial construction 21,615 43,889 514 26,218 47,519 900 Residential 100,415 128,357 4,931 105,785 134,093 4,296 Residential Alt-A 118,287 148,411 10,000 127,889 161,529 11,000 Consumer: Home equity lines and loans 21,235 22,219 3,531 19,771 20,806 6,213 Automobile 25,175 25,175 6,334 30,317 30,317 8,070 Other 19,256 19,256 5,458 18,973 18,973 5,459 Total $ 784,348 978,555 80,917 762,455 953,794 82,643
Interest Income Recognized on Loans	Three months ended Three months ended Interest income Interest income Average Total Cash Average Total Cash (in thousands) Commercial, financial, leasing, etc. $ 221,952 502 502 150,625 220 220 Real estate: Commercial 153,105 1,004 1,004 207,633 869 869 Residential builder and developer 66,334 131 131 91,614 39 39 Other commercial construction 23,614 168 168 77,801 356 356 Residential 101,560 1,358 785 119,133 5,056 4,468 Residential Alt-A 120,286 1,650 697 134,895 1,733 660 Consumer: Home equity lines and loans 20,221 224 65 18,762 200 72 Automobile 26,123 416 43 36,631 589 74 Other 19,058 185 30 18,309 166 49 Total $ 752,253 5,638 3,425 855,403 9,228 6,807 Six months ended Six months ended Interest income Interest income Average Total Cash Average Total Cash (in thousands) Commercial, financial, leasing, etc. $ 218,285 1,106 1,106 142,466 768 768 Real estate: Commercial 153,088 2,106 2,106 196,529 1,795 1,795 Residential builder and developer 69,742 194 194 96,434 113 113 Other commercial construction 24,577 223 223 82,546 1,443 1,443 Residential 103,025 2,804 1,695 146,651 6,456 5,370 Residential Alt-A 122,970 3,260 1,344 137,273 3,359 1,219 Consumer: Home equity lines and loans 19,952 425 113 17,219 321 101 Automobile 27,568 866 97 38,007 1,214 161 Other 18,960 359 63 18,005 340 101 Total $ 758,167 11,343 6,941 875,130 15,809 11,071
Summary of Loan Grades	The following table summarizes the loan grades applied to the various classes of the Company’s commercial and commercial real estate loans. Real Estate Commercial, Commercial Residential Other (in thousands) June 30, 2015 Pass $ 19,079,109 21,885,377 1,690,496 3,549,397 Criticized accrual 821,574 846,024 60,151 165,520 Criticized nonaccrual 210,345 167,520 56,854 21,149 Total $ 20,111,028 22,898,921 1,807,501 3,736,066 December 31, 2014 Pass $ 18,695,440 21,837,022 1,347,778 3,347,522 Criticized accrual 588,407 578,317 45,845 172,269 Criticized nonaccrual 177,445 141,600 71,517 25,699 Total $ 19,461,292 22,556,939 1,465,140 3,545,490
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, Real Estate Commercial Residential Consumer Total (in thousands) June 30, 2015 Individually evaluated for impairment $ 31,098 19,296 14,904 15,323 $ 80,621 Collectively evaluated for impairment 253,312 290,853 43,428 177,444 765,037 Purchased impaired 2,340 1,145 1,962 1,471 6,918 Allocated $ 286,750 311,294 60,294 194,238 852,576 Unallocated 77,411 Total $ 929,987 December 31, 2014 Individually evaluated for impairment $ 31,779 15,490 14,703 19,742 $ 81,714 Collectively evaluated for impairment 251,607 291,244 45,061 165,140 753,052 Purchased impaired 4,652 1,193 2,146 1,151 9,142 Allocated $ 288,038 307,927 61,910 186,033 843,908 Unallocated 75,654 Total $ 919,562
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, Real Estate Commercial Residential Consumer Total (in thousands) June 30, 2015 Individually evaluated for impairment $ 239,556 259,441 218,410 65,666 $ 783,073 Collectively evaluated for impairment 19,866,199 28,037,245 8,210,328 11,065,167 67,178,939 Purchased impaired 5,273 145,802 15,804 2,361 169,240 Total $ 20,111,028 28,442,488 8,444,542 11,133,194 $ 68,131,252 December 31, 2014 Individually evaluated for impairment $ 206,318 252,347 232,398 69,061 $ 760,124 Collectively evaluated for impairment 19,244,674 27,148,382 8,406,680 10,911,359 65,711,095 Purchased impaired 10,300 166,840 18,223 2,374 197,737 Total $ 19,461,292 27,567,569 8,657,301 10,982,794 $ 66,668,956
Loan Modification Activities that were Considered Troubled Debt Restructurings	The tables below summarize the Company’s loan modification activities that were considered troubled debt restructurings for the three months ended June 30, 2015 and 2014: Recorded investment Financial effects of Three months ended June 30, 2015 Number Pre- Post- Recorded Interest (dollars in thousands) Commercial, financial, leasing, etc. Principal deferral 30 $ 16,018 $ 15,355 $ (663 ) $ — Other 2 8,991 8,883 (108 ) — Combination of concession types 2 15,889 17,864 1,975 (239 ) Real estate: Commercial Principal deferral 15 38,983 37,585 (1,398 ) — Combination of concession types 1 436 436 — (53 ) Residential builder and developer Principal deferral 1 9,252 9,200 (52 ) — Residential Principal deferral 12 693 754 61 — Combination of concession types 9 961 1,066 105 (144 ) Residential Alt-A Principal deferral 1 161 161 — — Combination of concession types 2 424 426 2 (26 ) Consumer: Home equity lines and loans Principal deferral 1 1,198 1,198 — — Combination of concession types 14 1,356 1,356 — (212 ) Automobile Principal deferral 63 615 615 — — Interest rate reduction 4 95 95 — (7 ) Other 13 21 21 — — Combination of concession types 9 138 138 — (4 ) Other Principal deferral 27 770 770 — — Other 2 21 21 — — Combination of concession types 10 43 43 — (7 ) Total 218 $ 96,065 $ 95,987 $ (78 ) $ (692 ) (a) Financial effects impacting the recorded investment included principal payments or advances, charge-offs and capitalized escrow arrearages. (b) Represents the present value of interest rate concessions discounted at the effective rate of the original loan. Recorded investment Financial effects of Three months ended June 30, 2014 Number Pre- Post- Recorded Interest (dollars in thousands) Commercial, financial, leasing, etc. Principal deferral 21 $ 4,414 $ 4,351 $ (63 ) $ — Other 1 19,593 19,593 — — Combination of concession types 3 9,795 9,727 (68 ) (10 ) Real estate: Commercial Principal deferral 11 8,327 8,314 (13 ) — Interest rate reduction 1 255 252 (3 ) (48 ) Combination of concession types 1 63 61 (2 ) (9 ) Residential builder and developer Principal deferral 1 1,398 1,398 — — Other commercial construction Principal deferral 2 6,407 6,318 (89 ) — Residential Principal deferral 3 142 166 24 — Combination of concession types 8 923 991 68 (66 ) Residential Alt-A Principal deferral 3 662 698 36 — Combination of concession types 6 1,006 1,029 23 (220 ) Consumer: Home equity lines and loans Interest rate reduction 5 341 341 — (76 ) Combination of concession types 21 1,772 1,772 — (204 ) Automobile Principal deferral 43 603 603 — — Interest rate reduction 3 60 60 — (3 ) Other 8 47 47 — — Combination of concession types 23 341 341 — (36 ) Other Principal deferral 7 38 38 — — Interest rate reduction 3 291 291 — (63 ) Combination of concession types 19 906 906 — (276 ) Total 193 $ 57,384 $ 57,297 $ (87 ) $ (1,011 ) (a) Financial effects impacting the recorded investment included principal payments or advances, charge-offs and capitalized escrow arrearages. (b) Represents the present value of interest rate concessions discounted at the effective rate of the original loan. The tables below summarize the Company’s loan modification activities that were considered troubled debt restructurings for the six months ended June 30, 2015 and 2014: Recorded investment Financial effects of Six months ended June 30, 2015 Number Pre- Post- Recorded Interest (dollars in thousands) Commercial, financial, leasing, etc. Principal deferral 51 $ 17,590 $ 16,912 $ (678 ) $ — Interest rate reduction 1 99 99 — (19 ) Other 2 8,991 8,883 (108 ) — Combination of concession types 5 25,044 24,853 (191 ) (239 ) Real estate: Commercial Principal deferral 22 42,775 41,361 (1,414 ) — Combination of concession types 5 2,082 2,073 (9 ) (105 ) Residential builder and developer Principal deferral 2 10,650 10,598 (52 ) — Residential Principal deferral 19 1,414 1,496 82 — Combination of concession types 12 1,255 1,415 160 (178 ) Residential Alt-A Principal deferral 1 161 161 — — Combination of concession types 3 634 636 2 (30 ) Consumer: Home equity lines and loans Principal deferral 2 1,219 1,219 — — Combination of concession types 19 1,552 1,552 — (225 ) Automobile Principal deferral 98 918 918 — — Interest rate reduction 7 137 137 — (10 ) Other 23 41 41 — — Combination of concession types 17 222 222 — (11 ) Other Principal deferral 49 1,066 1,066 — — Other 7 80 80 — — Combination of concession types 23 267 267 — (32 ) Total 368 $ 116,197 $ 113,989 $ (2,208 ) $ (849 ) (a) Financial effects impacting the recorded investment included principal payments or advances, charge-offs and capitalized escrow arrearages. (b) Represents the present value of interest rate concessions discounted at the effective rate of the original loan. Recorded investment Financial effects of Six months ended June 30, 2014 Number Pre- Post- Recorded Interest (dollars in thousands) Commercial, financial, leasing, etc. Principal deferral 51 $ 19,368 $ 19,199 $ (169 ) $ — Other 1 19,593 19,593 — — Combination of concession types 5 9,836 9,766 (70 ) (14 ) Real estate: Commercial Principal deferral 24 15,371 15,316 (55 ) — Interest rate reduction 1 255 252 (3 ) (48 ) Combination of concession types 2 409 462 53 (113 ) Residential builder and developer Principal deferral 1 1,398 1,398 — — Other commercial construction Principal deferral 3 6,558 6,469 (89 ) — Residential Principal deferral 16 1,744 1,829 85 — Interest rate reduction 1 98 104 6 (32 ) Other 1 188 188 — — Combination of concession types 22 3,111 3,151 40 (348 ) Residential Alt-A Principal deferral 5 828 900 72 — Combination of concession types 16 2,752 2,765 13 (281 ) Consumer: Home equity lines and loans Principal deferral 3 280 280 — — Interest rate reduction 5 341 341 — (76 ) Combination of concession types 36 3,628 3,628 — (376 ) Automobile Principal deferral 123 1,596 1,596 — — Interest rate reduction 3 60 60 — (3 ) Other 19 108 108 — — Combination of concession types 46 591 591 — (62 ) Other Principal deferral 15 93 93 — — Interest rate reduction 3 291 291 — (63 ) Other 1 45 45 — — Combination of concession types 33 1,372 1,372 — (464 ) Total 436 $ 89,914 $ 89,797 $ (117 ) $ (1,880 ) (a) Financial effects impacting the recorded investment included principal payments or advances, charge-offs and capitalized escrow arrearages. (b) Represents the present value of interest rate concessions discounted at the effective rate of the original loan.

Shareholders' equity (Tables)

Shareholders' equity (Tables)	6 Months Ended
	Jun. 30, 2015
Equity [Abstract]
Issued and Outstanding Preferred Stock	Issued and outstanding preferred stock of M&T as of June 30, 2015 and December 31, 2014 is presented below: Shares Carrying value (dollars in thousands) Series A (a) Fixed Rate Cumulative Perpetual Preferred Stock, Series A, $1,000 liquidation preference per share 230,000 $ 230,000 Series C (a) Fixed Rate Cumulative Perpetual Preferred Stock, Series C, $1,000 liquidation preference per share 151,500 $ 151,500 Series D (b) Fixed Rate Non-Cumulative Perpetual Preferred Stock, Series D, $10,000 liquidation preference per share 50,000 $ 500,000 Series E (c) Fixed-to-Floating Rate Non-Cumulative Perpetual Preferred Stock Series E, $1,000 liquidation preference per share 350,000 $ 350,000 (a) Dividends, if declared, are paid at 6.375%. Warrants to purchase M&T common stock at $73.86 per share issued in connection with the Series A preferred stock expire in 2018 and totaled 719,175 at June 30, 2015 and 721,490 at December 31, 2014. (b) Dividends, if declared, are paid semi-annually at a rate of 6.875% per year. The shares are redeemable in whole or in part on or after June 15, 2016. Notwithstanding M&T’s option to redeem the shares, if an event occurs such that the shares no longer qualify as Tier 1 capital, M&T may redeem all of the shares within 90 days following that occurrence. (c) Dividends, if declared, are paid semi-annually at a rate of 6.45% through February 14, 2024 and thereafter will be paid quarterly at a rate of the three-month London Interbank Offered Rate (“LIBOR”) plus 361 basis points (hundredths of one percent). The shares are redeemable in whole or in part on or after February 15, 2024. Notwithstanding M&T’s option to redeem the shares, if an event occurs such that the shares no longer qualify as Tier 1 capital, M&T may redeem all of the shares within 90 days following that occurrence.

Pension plans and other postr29

Pension plans and other postretirement benefits (Tables)	6 Months Ended
	Jun. 30, 2015
Compensation and Retirement Disclosure [Abstract]
Net Periodic Pension Expense for Defined Benefit Plans	Net periodic defined benefit cost for defined benefit plans consisted of the following: Pension Other Three months ended June 30 2015 2014 2015 2014 (in thousands) Service cost $ 5,832 5,160 174 152 Interest cost on projected benefit obligation 17,732 17,331 652 714 Expected return on plan assets (23,476 ) (22,859 ) — — Amortization of prior service credit (1,478 ) (1,626 ) (329 ) (329 ) Amortization of net actuarial loss 11,237 3,897 28 — Net periodic benefit cost $ 9,847 1,903 525 537 Pension Other Six months ended June 30 2015 2014 2015 2014 (in thousands) Service cost $ 11,832 10,260 374 302 Interest cost on projected benefit obligation 35,507 34,581 1,302 1,389 Expected return on plan assets (47,051 ) (45,784 ) — — Amortization of prior service credit (3,003 ) (3,276 ) (679 ) (679 ) Amortization of net actuarial loss 22,412 7,247 53 — Net periodic benefit cost $ 19,697 3,028 1,050 1,012

Earnings per common share (Tabl

Earnings per common share (Tables)	6 Months Ended
	Jun. 30, 2015
Earnings Per Share [Abstract]
Computations of Basic Earnings Per Common Share	The computations of basic earnings per common share follow: Three months ended June 30 Six months ended June 30 2015 2014 2015 2014 (in thousands, except per share) Income available to common shareholders: Net income $ 286,688 284,336 $ 528,301 513,353 Less: Preferred stock dividends (a) (20,317 ) (20,443 ) (40,635 ) (35,117 ) Net income available to common equity 266,371 263,893 487,666 478,236 Less: Income attributable to unvested stock-based compensation awards (2,900 ) (3,213 ) (5,371 ) (5,832 ) Net income available to common shareholders $ 263,471 260,680 $ 482,295 472,404 Weighted-average shares outstanding: Common shares outstanding (including common stock issuable) and unvested stock-based compensation awards 133,818 132,473 133,680 132,139 Less: Unvested stock-based compensation awards (1,462 ) (1,617 ) (1,477 ) (1,603 ) Weighted-average shares outstanding 132,356 130,856 132,203 130,536 Basic earnings per common share $ 1.99 1.99 $ 3.65 3.62 (a) Including impact of not as yet declared cumulative dividends.
Computations of Diluted Earnings Per Common Share	The computations of diluted earnings per common share follow: Three months ended June 30 Six months ended June 30 2015 2014 2015 2014 (in thousands, except per share) Net income available to common equity $ 266,371 263,893 $ 487,666 478,236 Less: Income attributable to unvested stock-based compensation awards (2,890 ) (3,198 ) (5,353 ) (5,807 ) Net income available to common shareholders $ 263,481 260,695 $ 482,313 472,429 Adjusted weighted-average shares outstanding: Common and unvested stock-based compensation awards 133,818 132,473 133,680 132,139 Less: Unvested stock-based compensation awards (1,462 ) (1,617 ) (1,477 ) (1,603 ) Plus: Incremental shares from assumed conversion of stock-based compensation awards and warrants to purchase common stock 760 972 741 943 Adjusted weighted-average shares outstanding 133,116 131,828 132,944 131,479 Diluted earnings per common share $ 1.98 1.98 $ 3.63 3.59

Comprehensive income (Tables)

Comprehensive income (Tables)	6 Months Ended
	Jun. 30, 2015
Equity [Abstract]
Components of Other Comprehensive Income (Loss) and Amounts Reclassified from Accumulated Other Comprehensive Income (Loss) to Net Income	The following tables display the components of other comprehensive income (loss) and amounts reclassified from accumulated other comprehensive income (loss) to net income: Investment Securities With All Defined Other Total Income Net (in thousands) Balance – January 1, 2015 $ 7,438 201,828 (503,027 ) (4,082 ) $ (297,843 ) 116,849 $ (180,994 ) Other comprehensive income before reclassifications: Unrealized holding gains, net 5,670 (85,602 ) — — (79,932 ) 31,617 (48,315 ) Foreign currency translation adjustment — — — (779 ) (779 ) 261 (518 ) Gains on cash flow hedges — — — 1,453 1,453 (568 ) 885 Total other comprehensive income before reclassifications 5,670 (85,602 ) — 674 (79,258 ) 31,310 (47,948 ) Amounts reclassified from accumulated other comprehensive income that (increase) decrease net income: Accretion of unrealized holding losses on held-to-maturity (“HTM”) securities — 1,589 — — 1,589 (b) (621 ) 968 Losses realized in net income — 108 — — 108 (c) (40 ) 68 Accretion of net gain on terminated cash flow hedges — — — (63 ) (63 ) (d) 25 (38 ) Amortization of prior service credit — — (3,682 ) — (3,682 ) (e) 1,640 (2,042 ) Amortization of actuarial losses — — 22,465 — 22,465 (e) (9,981 ) 12,484 Total reclassifications — 1,697 18,783 (63 ) 20,417 (8,977 ) 11,440 Total gain (loss) during the period 5,670 (83,905 ) 18,783 611 (58,841 ) 22,333 (36,508 ) Balance – June 30, 2015 $ 13,108 117,923 (484,244 ) (3,471 ) $ (356,684 ) 139,182 $ (217,502 ) Investment Securities With All Defined Other Total Income Net (in thousands) Balance – January 1, 2014 $ 37,255 18,450 (161,617 ) 115 $ (105,797 ) 41,638 $ (64,159 ) Other comprehensive income before reclassifications: Unrealized holding gains, net 10,842 156,764 — — 167,606 (65,774 ) 101,832 Foreign currency translation adjustment — — — 479 479 (166 ) 313 Unrealized losses on cash flow hedges — — — (1,170 ) (1,170 ) 459 (711 ) Total other comprehensive income before reclassifications 10,842 156,764 — (691 ) 166,915 (65,481 ) 101,434 Amounts reclassified from accumulated other comprehensive income that (increase) decrease net income: Accretion of unrealized holding losses on HTM securities 1 1,702 — — 1,703 (b) (669 ) 1,034 Amortization of prior service credit — — (3,955 ) — (3,955 ) (e) 1,552 (2,403 ) Amortization of actuarial losses — — 7,247 — 7,247 (e) (2,845 ) 4,402 Total reclassifications 1 1,702 3,292 — 4,995 (1,962 ) 3,033 Total gain (loss) during the period 10,843 158,466 3,292 (691 ) 171,910 (67,443 ) 104,467 Balance – June 30, 2014 $ 48,098 176,916 (158,325 ) (576 ) $ 66,113 (25,805 ) $ 40,308 (a) Other-than-temporary impairment (b) Included in interest income (c) Included in loss on bank investment securities (d) Included in interest expense (e) Included in salaries and employee benefits expense
Accumulated Other Comprehensive Income (Loss), Net	Accumulated other comprehensive income (loss), net consisted of the following: Investment securities Defined With OTTI All other plans Other Total (in thousands) Balance – December 31, 2014 $ 4,518 122,683 (305,589 ) (2,606 ) $ (180,994 ) Net gain (loss) during period 3,471 (50,750 ) 10,442 329 (36,508 ) Balance – June 30, 2015 $ 7,989 71,933 (295,147 ) (2,277 ) $ (217,502 )

Derivative financial instrume32

Derivative financial instruments (Tables)	6 Months Ended
	Jun. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Information about Interest Rate Swap Agreements	Information about interest rate swap agreements entered into for interest rate risk management purposes summarized by type of financial instrument the swap agreements were intended to hedge follows: Notional Average Weighted- Fixed Variable (in thousands) (in years) June 30, 2015 Fair value hedges: Fixed rate long-term borrowings (a) $ 1,400,000 2.2 4.42 % 1.24 % December 31, 2014 Fair value hedges: Fixed rate long-term borrowings (a) $ 1,400,000 2.7 4.42 % 1.19 % (a) Under the terms of these agreements, the Company receives settlement amounts at a fixed rate and pays at a variable rate.
Information about Fair Values of Derivative Instruments in Consolidated Balance Sheet	Information about the fair values of derivative instruments in the Company’s consolidated balance sheet and consolidated statement of income follows: Asset derivatives Liability derivatives Fair value Fair value June 30, December 31, June 30, December 31, (in thousands) Derivatives designated and qualifying as hedging instruments Fair value hedges: Interest rate swap agreements (a) $ 63,501 73,251 $ — — Commitments to sell real estate loans (a) 12,150 728 579 4,217 75,651 73,979 579 4,217 Derivatives not designated and qualifying as hedging instruments Mortgage-related commitments to originate real estate loans for sale (a) 12,755 17,396 1,549 49 Commitments to sell real estate loans (a) 2,645 754 1,946 4,330 Trading: Interest rate contracts (b) 202,052 215,614 158,670 173,513 Foreign exchange and other option and futures contracts (b) 16,424 31,112 13,826 29,950 233,876 264,876 175,991 207,842 Total derivatives $ 309,527 338,855 $ 176,570 212,059 (a) Asset derivatives are reported in other assets and liability derivatives are reported in other liabilities. (b) Asset derivatives are reported in trading account assets and liability derivatives are reported in other liabilities.
Information about Fair Values of Derivative Instruments in Consolidated Statement of Income	Amount of unrealized gain (loss) recognized Three months ended Three months ended Derivative Hedged item Derivative Hedged item (in thousands) Derivatives in fair value hedging relationships Interest rate swap agreements: Fixed rate long-term borrowings (a) $ (9,354 ) 8,952 $ (1,675 ) 1,358 Derivatives not designated as hedging instruments Trading: Interest rate contracts (b) $ 1,772 $ 1,384 Foreign exchange and other option and futures contracts (b) (711 ) (786 ) Total $ 1,061 $ 598 Amount of unrealized gain (loss) recognized Six months ended Six months ended Derivative Hedged item Derivative Hedged item (in thousands) Derivatives in fair value hedging relationships Interest rate swap agreements: Fixed rate long-term borrowings (a) $ (9,750 ) 9,113 $ (9,835 ) 9,278 Derivatives not designated as hedging instruments Trading: Interest rate contracts (b) $ 2,432 $ 1,082 Foreign exchange and other option and futures contracts (b) (878 ) (5,816 ) Total $ 1,554 $ (4,734 ) (a) Reported as other revenues from operations. (b) Reported as trading account and foreign exchange gains.

Fair value measurements (Tables

Fair value measurements (Tables)	6 Months Ended
	Jun. 30, 2015
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Estimated Fair Value on Recurring Basis	The following tables present assets and liabilities at June 30, 2015 and December 31, 2014 measured at estimated fair value on a recurring basis: Fair value Level 1 (a) Level 2 (a) Level 3 (in thousands) Trading account assets $ 277,009 49,052 227,957 — Investment securities available for sale: U.S. Treasury and federal agencies 198,718 — 198,718 — Obligations of states and political subdivisions 7,504 — 7,504 — Mortgage-backed securities: Government issued or guaranteed 10,771,892 — 10,771,892 — Privately issued 88 — — 88 Collateralized debt obligations 50,483 — — 50,483 Other debt securities 121,954 — 121,954 — Equity securities 100,238 75,427 24,811 — 11,250,877 75,427 11,124,879 50,571 Real estate loans held for sale 798,404 — 798,404 — Other assets (b) 91,051 — 78,296 12,755 Total assets $ 12,417,341 124,479 12,229,536 63,326 Trading account liabilities $ 172,496 — 172,496 — Other liabilities (b) 4,074 — 2,525 1,549 Total liabilities $ 176,570 — 175,021 1,549 Fair value Level 1 (a) Level 2 (a) Level 3 (in thousands) Trading account assets $ 308,175 51,416 256,759 — Investment securities available for sale: U.S. Treasury and federal agencies 161,947 — 161,947 — Obligations of states and political subdivisions 8,198 — 8,198 — Mortgage-backed securities: Government issued or guaranteed 8,731,123 — 8,731,123 — Privately issued 103 — — 103 Collateralized debt obligations 50,316 — — 50,316 Other debt securities 121,488 — 121,488 — Equity securities 83,757 64,841 18,916 — 9,156,932 64,841 9,041,672 50,419 Real estate loans held for sale 742,249 — 742,249 — Other assets (b) 92,129 — 74,733 17,396 Total assets $ 10,299,485 116,257 10,115,413 67,815 Trading account liabilities $ 203,464 — 203,464 — Other liabilities (b) 8,596 — 8,547 49 Total liabilities $ 212,060 — 212,011 49 (a) There were no significant transfers between Level 1 and Level 2 of the fair value hierarchy during the six months ended June 30, 2015 and the year ended December 31, 2014. (b) Comprised predominantly of interest rate swap agreements used for interest rate risk management (Level 2), commitments to sell real estate loans (Level 2) and commitments to originate real estate loans to be held for sale (Level 3).
Changes in Level 3 Assets and Liabilities Measured at Estimated Fair Value on Recurring Basis	The changes in Level 3 assets and liabilities measured at estimated fair value on a recurring basis during the three months ended June 30, 2015 were as follows: Investment securities available for sale Privately issued mortgage-backed Collateralized Other assets (in thousands) Balance – March 31, 2015 $ 95 $ 47,278 $ 26,230 Total gains realized/unrealized: Included in earnings — — 16,132 (a) Included in other comprehensive income — 7,629 (d) — Sales — — — Settlements (7 ) (4,424 ) — Transfers in and/or out of Level 3 (b) — — (31,156 )(c) Balance – June 30, 2015 $ 88 $ 50,483 $ 11,206 Changes in unrealized gains included in earnings related to assets still held at June 30, 2015 $ — $ — $ 6,330 (a) The changes in Level 3 assets and liabilities measured at estimated fair value on a recurring basis during the three months ended June 30, 2014 were as follows: Investment securities available for sale Privately issued mortgage-backed Collateralized Other assets (in thousands) Balance – March 31, 2014 $ 696 $ 61,768 $ 12,589 Total gains realized/unrealized: Included in earnings — — 31,517 (a) Included in other comprehensive income 205 (d) 4,486 (d) — Sales — — — Settlements (782 ) (10,054 ) — Transfers in and/or out of Level 3 (b) — — (22,083 )(c) Balance – June 30, 2014 $ 119 $ 56,200 $ 22,023 Changes in unrealized gains included in earnings related to assets still held at June 30, 2014 $ — $ — $ 20,215 (a) The changes in Level 3 assets and liabilities measured at estimated fair value on a recurring basis during the six months ended June 30, 2015 were as follows: Investment securities available for sale Privately issued mortgage-backed Collateralized Other assets (in thousands) Balance – January 1, 2015 $ 103 $ 50,316 $ 17,347 Total gains realized/unrealized: Included in earnings — — 45,902 (a) Included in other comprehensive income — 5,625 (d) — Settlements (15 ) (5,458 ) — Transfers in and/or out of Level 3 (b) — — (52,043 )(c) Balance – June 30, 2015 $ 88 $ 50,483 $ 11,206 Changes in unrealized gains included in earnings related to assets still held at June 30, 2015 $ — $ — $ 8,763 (a) The changes in Level 3 assets and liabilities measured at estimated fair value on a recurring basis during the six months ended June 30, 2014 were as follows: Investment securities available for sale Privately issued mortgage-backed Collateralized Other assets (in thousands) Balance – January 1, 2014 $ 1,850 $ 63,083 $ 3,941 Total gains realized/unrealized: Included in earnings — — 53,900 (a) Included in other comprehensive income 272 (d) 9,132 (d) — Settlements (2,003 ) (16,015 ) — Transfers in and/or out of Level 3 (b) — — (35,818 )(c) Balance – June 30, 2014 $ 119 $ 56,200 $ 22,023 Changes in unrealized gains included in earnings related to assets still held at June 30, 2014 $ — $ — $ 24,099 (a) (a) Reported as mortgage banking revenues in the consolidated statement of income and includes the fair value of commitment issuances and expirations. (b) The Company’s policy for transfers between fair value levels is to recognize the transfer as of the actual date of the event or change in circumstances that caused the transfer. (c) Transfers out of Level 3 consist of interest rate locks transferred to closed loans. (d) Reported as net unrealized gains (losses) on investment securities in the consolidated statement of comprehensive income.
Quantitative Information Related to Significant Unobservable Inputs	The following tables present quantitative information about the significant unobservable inputs used in the fair value measurements for Level 3 assets and liabilities at June 30, 2015 and December 31, 2014: Fair value at Valuation Unobservable Range (in thousands) Recurring fair value measurements Privately issued mortgage–backed securities $ 88 Two — — Collateralized debt obligations 50,483 Discounted Probability 12%-57% (37%) Loss severity 100% Net other assets (liabilities) (a) 11,206 Discounted Commitment 0%-95% (24%) Fair value at Valuation Unobservable Range (in thousands) Recurring fair value measurements Privately issued mortgage–backed securities $ 103 Two — — Collateralized debt obligations 50,316 Discounted Probability 12%-57% (36%) Loss severity 100% Net other assets (liabilities) (a) 17,347 Discounted Commitment 0%-96% (17%) (a) Other Level 3 assets (liabilities) consist of commitments to originate real estate loans.
Carrying Amounts and Estimated Fair Value for Financial Instrument Assets (Liabilities)	The carrying amounts and estimated fair value for financial instrument assets (liabilities) are presented in the following table: June 30, 2015 Carrying Estimated Level 1 Level 2 Level 3 (in thousands) Financial assets: Cash and cash equivalents $ 1,350,858 $ 1,350,858 $ 1,291,501 $ 59,357 $ — Interest-bearing deposits at banks 4,045,852 4,045,852 — 4,045,852 — Trading account assets 277,009 277,009 49,052 227,957 — Investment securities 14,751,637 14,762,899 75,427 14,479,134 208,338 Loans and leases: Commercial loans and leases 20,111,028 19,822,748 — — 19,822,748 Commercial real estate loans 28,442,488 28,321,200 — 319,877 28,001,323 Residential real estate loans 8,444,542 8,465,046 — 5,024,771 3,440,275 Consumer loans 11,133,194 11,014,334 — — 11,014,334 Allowance for credit losses (929,987 ) — — — — Loans and leases, net 67,201,265 67,623,328 — 5,344,648 62,278,680 Accrued interest receivable 228,126 228,126 — 228,126 — Financial liabilities: Noninterest-bearing deposits $ (27,674,588 ) $ (27,674,588 ) $ — $ (27,674,588 ) $ — Savings deposits and NOW accounts (41,885,954 ) (41,885,954 ) — (41,885,954 ) — Time deposits (2,901,636 ) (2,921,070 ) — (2,921,070 ) — Deposits at Cayman Islands office (167,441 ) (167,441 ) — (167,441 ) — Short-term borrowings (153,299 ) (153,299 ) — (153,299 ) — Long-term borrowings (10,175,912 ) (10,219,668 ) — (10,219,668 ) — Accrued interest payable (72,062 ) (72,062 ) — (72,062 ) — Trading account liabilities (172,496 ) (172,496 ) — (172,496 ) — Other financial instruments: Commitments to originate real estate loans for sale $ 11,206 $ 11,206 $ — $ — $ 11,206 Commitments to sell real estate loans 12,270 12,270 — 12,270 — Other credit-related commitments (121,385 ) (121,385 ) — — (121,385 ) Interest rate swap agreements used for interest rate risk management 63,501 63,501 — 63,501 — December 31, 2014 Carrying Estimated Level 1 Level 2 Level 3 (in thousands) Financial assets: Cash and cash equivalents $ 1,373,357 $ 1,373,357 $ 1,296,923 $ 76,434 $ — Interest-bearing deposits at banks 6,470,867 6,470,867 — 6,470,867 — Trading account assets 308,175 308,175 51,416 256,759 — Investment securities 12,993,542 13,023,956 64,841 12,750,396 208,719 Loans and leases: Commercial loans and leases 19,461,292 19,188,574 — — 19,188,574 Commercial real estate loans 27,567,569 27,487,818 — 307,667 27,180,151 Residential real estate loans 8,657,301 8,729,056 — 5,189,086 3,539,970 Consumer loans 10,982,794 10,909,623 — — 10,909,623 Allowance for credit losses (919,562 ) — — — — Loans and leases, net 65,749,394 66,315,071 — 5,496,753 60,818,318 Accrued interest receivable 227,348 227,348 — 227,348 — Financial liabilities: Noninterest-bearing deposits $ (26,947,880 ) $ (26,947,880 ) $ — $ (26,947,880 ) $ — Savings deposits and NOW accounts (43,393,618 ) (43,393,618 ) — (43,393,618 ) — Time deposits (3,063,973 ) (3,086,126 ) — (3,086,126 ) — Deposits at Cayman Islands office (176,582 ) (176,582 ) — (176,582 ) — Short-term borrowings (192,676 ) (192,676 ) — (192,676 ) — Long-term borrowings (9,006,959 ) (9,139,789 ) — (9,139,789 ) — Accrued interest payable (63,372 ) (63,372 ) — (63,372 ) — Trading account liabilities (203,464 ) (203,464 ) — (203,464 ) — Other financial instruments: Commitments to originate real estate loans for sale $ 17,347 $ 17,347 $ — $ — $ 17,347 Commitments to sell real estate loans (7,065 ) (7,065 ) — (7,065 ) — Other credit-related commitments (119,079 ) (119,079 ) — — (119,079 ) Interest rate swap agreements used for interest rate risk management 73,251 73,251 — 73,251 —

Commitments and contingencies (

Commitments and contingencies (Tables)	6 Months Ended
	Jun. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Company's Significant Commitments	The following table presents the Company’s significant commitments. Certain of these commitments are not included in the Company’s consolidated balance sheet. June 30, December 31, (in thousands) Commitments to extend credit Home equity lines of credit $ 5,612,243 6,194,516 Commercial real estate loans to be sold 104,832 212,257 Other commercial real estate and construction 5,601,820 4,834,699 Residential real estate loans to be sold 671,670 432,352 Other residential real estate 719,788 524,399 Commercial and other 11,439,086 11,080,856 Standby letters of credit 3,531,401 3,706,888 Commercial letters of credit 42,858 46,965 Financial guarantees and indemnification contracts 2,795,007 2,490,050 Commitments to sell real estate loans 1,354,654 1,237,294

Segment information (Tables)

Segment information (Tables)	6 Months Ended
	Jun. 30, 2015
Segment Reporting [Abstract]
Summary of Prior Period Financial Information Restated	As a result of the changes, prior period financial information has been restated to provide segment information on a comparable basis, as noted in the following tables. Three months ended June 30, 2014 Net income (loss) as Impact of Net income (loss) (in thousands) Business Banking $ 27,760 (4,008 ) 23,752 Commercial Banking 105,358 (1,267 ) 104,091 Commercial Real Estate 77,526 (1,798 ) 75,728 Discretionary Portfolio 14,980 63 15,043 Residential Mortgage Banking 27,712 (1,063 ) 26,649 Retail Banking 32,034 40,939 72,973 All Other (1,034 ) (32,866 ) (33,900 ) Total $ 284,336 — 284,336 Six months ended June 30, 2014 Net income (loss) as Impact of Net income (loss) (in thousands) Business Banking $ 56,358 (7,633 ) 48,725 Commercial Banking 205,123 (2,191 ) 202,932 Commercial Real Estate 152,087 (3,807 ) 148,280 Discretionary Portfolio 26,259 144 26,403 Residential Mortgage Banking 47,123 (1,894 ) 45,229 Retail Banking 61,745 80,262 142,007 All Other (35,342 ) (64,881 ) (100,223 ) Total $ 513,353 — 513,353
Information about Company's Segments	Information about the Company’s segments is presented in the following table: Three months ended June 30 2015 2014 Total Inter- Net Total Inter- Net (in thousands) Business Banking $ 111,131 1,122 25,354 112,734 1,220 23,752 Commercial Banking 257,257 1,099 108,081 252,347 1,356 104,091 Commercial Real Estate 178,949 427 79,751 164,262 525 75,728 Discretionary Portfolio 20,477 (5,376 ) 10,756 29,912 (5,282 ) 15,043 Residential Mortgage Banking 112,029 12,436 27,699 109,837 11,772 26,649 Retail Banking 305,573 3,259 68,806 311,554 3,897 72,973 All Other 194,739 (12,967 ) (33,759 ) 144,880 (13,488 ) (33,900 ) Total $ 1,180,155 — 286,688 1,125,526 — 284,336 Six months ended June 30 2015 2014 Total Inter- Net Total Inter- Net (in thousands) Business Banking $ 219,691 2,167 50,165 224,504 2,277 48,725 Commercial Banking 503,838 2,184 204,504 501,696 2,553 202,932 Commercial Real Estate 342,269 509 159,837 321,585 873 148,280 Discretionary Portfolio 35,951 (10,819 ) 16,710 54,569 (10,321 ) 26,403 Residential Mortgage Banking 223,487 23,823 59,664 203,602 21,520 45,229 Retail Banking 605,964 6,396 137,694 618,334 7,402 142,007 All Other 348,746 (24,260 ) (100,273 ) 277,776 (24,304 ) (100,223 ) Total $ 2,279,946 — 528,301 2,202,066 — 513,353
Summary of Segment Information	Average total assets Six months ended June 30 Year ended December 31 2015 2014 2014 (in millions) Business Banking $ 5,313 5,286 5,281 Commercial Banking 23,997 22,742 22,892 Commercial Real Estate 18,191 16,878 17,113 Discretionary Portfolio 23,029 19,417 20,798 Residential Mortgage Banking 3,413 3,226 3,333 Retail Banking 10,830 10,229 10,449 All Other 11,977 10,500 12,277 Total $ 96,750 88,278 92,143 (a) Total revenues are comprised of net interest income and other income. Net interest income is the difference between taxable-equivalent interest earned on assets and interest paid on liabilities owed by a segment and a funding charge (credit) based on the Company ’ s internal funds transfer pricing and allocation methodology. Segments are charged a cost to fund any assets (e.g. loans) and are paid a funding credit for any funds provided (e.g. deposits). The taxable-equivalent adjustment aggregated $6,020,000 and $5,849,000 for the three-month periods ended June 30, 2015 and 2014, respectively, and $11,858,000 and $11,794,000 for the six-month periods ended June 30, 2015 and 2014, respectively, and is eliminated in “ All Other ” total revenues. Intersegment revenues are included in total revenues of the reportable segments. The elimination of intersegment revenues is included in the determination of “ All Other ” total revenues.

Significant Accounting Polici36

Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Significant Accounting Policies [Line Items]
Amount restated as a result of adoption of new guidance	$ 453,527	$ 427,866	$ 828,943	$ 782,172
Adjustments for New Accounting Pronouncement [Member]
Significant Accounting Policies [Line Items]
Amount restated as a result of adoption of new guidance		$ 14,000		$ 26,000

Acquisitions - Additional Infor

Acquisitions - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Jun. 30, 2015	Dec. 31, 2014	Aug. 27, 2012
Business Acquisition [Line Items]
Purchase consideration per common share			$ 0.08403
Percentage of total equity consideration			60.00%
Percentage of total cash consideration			40.00%
Total consideration to be paid	$ 5,500,000
Assets	97,080,076	$ 96,685,535
Loans	67,201,265	65,749,394
Liabilities	84,412,079	84,349,639
Deposits	72,629,619	$ 73,582,053
Hudson City [Member]
Business Acquisition [Line Items]
Assets	35,400,000
Loans	19,900,000
Investment securities	8,100,000
Liabilities	30,600,000
Deposits	$ 18,200,000

Investment Securities - Amortiz

Investment Securities - Amortized Cost and Estimated Fair Value of Investment Securities (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Other securities, Amortized cost	$ 336,175	$ 328,742
Other securities, Gross unrealized gains	0	0
Other securities, Gross unrealized losses	0	0
Other securities, Estimated fair value	336,175	328,742
Investment securities, available for sale, amortized cost	11,093,093	8,919,324
Investment securities available for sale, gross unrealized gains	216,819	258,851
Investment securities available for sale, gross unrealized losses	59,035	21,243
Investment securities available for sale, estimated fair value	11,250,877	9,156,932
Amortized cost for held to maturity	3,164,585	3,507,868
Gross unrealized gains for held to maturity	57,807	82,179
Gross unrealized losses for held to maturity	46,545	51,765
Estimated fair value for held to maturity	3,175,847	3,538,282
Total Amortized cost	14,593,853	12,755,934
Total for Gross unrealized gains	274,626	341,030
Total for Gross unrealized losses	105,580	73,008
Total for Estimated fair value	14,762,899	13,023,956
Obligations of States and Political Subdivisions [Member]
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Investment securities, available for sale, amortized cost	7,387	8,027
Investment securities available for sale, gross unrealized gains	169	224
Investment securities available for sale, gross unrealized losses	52	53
Investment securities available for sale, estimated fair value	7,504	8,198
Amortized cost for held to maturity	136,922	148,961
Gross unrealized gains for held to maturity	1,584	2,551
Gross unrealized losses for held to maturity	391	189
Estimated fair value for held to maturity	138,115	151,323
Government Issued or Guaranteed [Member]
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Investment securities, available for sale, amortized cost	10,637,736	8,507,571
Investment securities available for sale, gross unrealized gains	174,277	223,889
Investment securities available for sale, gross unrealized losses	40,121	337
Investment securities available for sale, estimated fair value	10,771,892	8,731,123
Amortized cost for held to maturity	2,828,638	3,149,320
Gross unrealized gains for held to maturity	54,355	78,485
Gross unrealized losses for held to maturity	10,143	7,000
Estimated fair value for held to maturity	2,872,850	3,220,805
Privately Issued [Member]
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Investment securities, available for sale, amortized cost	89	104
Investment securities available for sale, gross unrealized gains	2	2
Investment securities available for sale, gross unrealized losses	3	3
Investment securities available for sale, estimated fair value	88	103
Amortized cost for held to maturity	191,910	201,733
Gross unrealized gains for held to maturity	1,868	1,143
Gross unrealized losses for held to maturity	36,011	44,576
Estimated fair value for held to maturity	157,767	158,300
Other Debt Securities [Member]
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Investment securities, available for sale, amortized cost	138,525	138,240
Investment securities available for sale, gross unrealized gains	1,672	1,896
Investment securities available for sale, gross unrealized losses	18,243	18,648
Investment securities available for sale, estimated fair value	121,954	121,488
Amortized cost for held to maturity	7,115	7,854
Estimated fair value for held to maturity	7,115	7,854
U.S. Treasury and Federal Agencies [Member]
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Investment securities, available for sale, amortized cost	197,315	161,408
Investment securities available for sale, gross unrealized gains	1,404	544
Investment securities available for sale, gross unrealized losses	1	5
Investment securities available for sale, estimated fair value	198,718	161,947
Collateralized Debt Obligations [Member]
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Investment securities, available for sale, amortized cost	28,381	30,073
Investment securities available for sale, gross unrealized gains	22,518	21,276
Investment securities available for sale, gross unrealized losses	416	1,033
Investment securities available for sale, estimated fair value	50,483	50,316
Equity Securities [Member]
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Investment securities, available for sale, amortized cost	83,660	73,901
Investment securities available for sale, gross unrealized gains	16,777	11,020
Investment securities available for sale, gross unrealized losses	199	1,164
Investment securities available for sale, estimated fair value	$ 100,238	$ 83,757

Investment Securities - Additio

Investment Securities - Additional Information (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2015USD ($)Investment	Jun. 30, 2014USD ($)	Jun. 30, 2015USD ($)Investment	Jun. 30, 2014USD ($)	Dec. 31, 2014USD ($)
Amortized Cost and Fair Value Debt Securities [Abstract]
Gross realized gain or loss on sale of Investment Securities	$ 0	$ 0	$ 0	$ 0
Number of investment securities with aggregate gross unrealized losses | Investment	383		383
Unrealized losses on individual investment securities	$ 105,580,000		$ 105,580,000		$ 73,008,000
Cost method investment securities	$ 336,000,000		$ 336,000,000

Investment Securities - Amort40

Investment Securities - Amortized Cost and Estimated Fair Value of Debt Securities by Contractual Maturity (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Debt securities available for sale:
Due in one year or less	$ 10,418
Due after one year through five years	197,809
Due after five years through ten years	2,619
Due after ten years	160,762
Total available for sale (amortized cost)	371,608
Mortgage-backed securities available for sale	10,637,825
Total	11,009,433
Debt securities held to maturity:
Due in one year or less	28,570
Due after one year through five years	83,513
Due after five years through ten years	24,839
Due after ten years	7,115
Total available for held to maturity (amortized cost)	144,037
Mortgage-backed securities held to maturity	3,020,548
Amortized cost for held to maturity	3,164,585	$ 3,507,868
Debt securities available for sale:
Due in one year or less	10,461
Due after one year through five years	199,557
Due after five years through ten years	2,637
Due after ten years	166,004
Total available for sale (fair value)	378,659
Mortgage-backed securities available for sale	10,771,980
Total	11,150,639
Debt securities held to maturity:
Due in one year or less	28,738
Due after one year through five years	84,258
Due after five years through ten years	25,119
Due after ten years	7,115
Total available for held to maturity (fair value)	145,230
Mortgage-backed securities held to maturity	3,030,617
Total	$ 3,175,847	$ 3,538,282

Investment Securities - Investm

Investment Securities - Investment Securities in Continuous Unrealized Loss Position (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Estimated fair value, Less than 12 months	$ 2,704,945	$ 65,554
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Aggregate Losses	(40,163)	(2,659)
Estimated fair value, 12 months or more	103,542	103,914
Available For Sale Securities Continuous Unrealized Loss Position Twelve Months Or More Aggregate Losses	(18,872)	(18,584)
Held to maturity, Estimated fair value, Less than 12 months	421,598	167,299
Held To Maturity Securities Continuous Unrealized Loss Position Less Than12 Months Aggregate Losses	(3,053)	(545)
Held to maturity, Estimated fair value, 12 months or more	379,641	574,560
Held To Maturity Securities Continuous Unrealized Loss Position12 Months Or Longer Aggregate Losses	(43,492)	(51,220)
Total investment securities, fair value less than 12 months	3,126,543	232,853
Investment Securities Continuous Unrealized Loss Position Less Than Twelve Months Aggregate Losses	(43,216)	(3,204)
Total of investment securities, fair value, 12 Months or More	483,183	678,474
Investment Securities Continuous Unrealized Loss Position Twelve Months or Longer Aggregate Losses	(62,364)	(69,804)
Obligations of States and Political Subdivisions [Member]
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Estimated fair value, Less than 12 months	1,403	1,785
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Aggregate Losses	(7)	(52)
Estimated fair value, 12 months or more	1,527	121
Available For Sale Securities Continuous Unrealized Loss Position Twelve Months Or More Aggregate Losses	(45)	(1)
Held to maturity, Estimated fair value, Less than 12 months	38,431	29,886
Held To Maturity Securities Continuous Unrealized Loss Position Less Than12 Months Aggregate Losses	(360)	(184)
Held to maturity, Estimated fair value, 12 months or more	2,289	268
Held To Maturity Securities Continuous Unrealized Loss Position12 Months Or Longer Aggregate Losses	(31)	(5)
Government Issued or Guaranteed [Member]
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Estimated fair value, Less than 12 months	2,688,635	39,001
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Aggregate Losses	(39,970)	(186)
Estimated fair value, 12 months or more	6,231	5,555
Available For Sale Securities Continuous Unrealized Loss Position Twelve Months Or More Aggregate Losses	(151)	(151)
Held to maturity, Estimated fair value, Less than 12 months	383,167	137,413
Held To Maturity Securities Continuous Unrealized Loss Position Less Than12 Months Aggregate Losses	(2,693)	(361)
Held to maturity, Estimated fair value, 12 months or more	249,870	446,780
Held To Maturity Securities Continuous Unrealized Loss Position12 Months Or Longer Aggregate Losses	(7,450)	(6,639)
Privately Issued [Member]
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Held to maturity, Estimated fair value, 12 months or more	127,482	127,512
Held To Maturity Securities Continuous Unrealized Loss Position12 Months Or Longer Aggregate Losses	(36,011)	(44,576)
U.S. Treasury and Federal Agencies [Member]
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Estimated fair value, Less than 12 months	1,750	6,505
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Aggregate Losses	(1)	(5)
Privately Issued Mortgage-Backed Securities [Member]
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Estimated fair value, Less than 12 months	15
Estimated fair value, 12 months or more	53	65
Available For Sale Securities Continuous Unrealized Loss Position Twelve Months Or More Aggregate Losses	(3)	(3)
Collateralized Debt Obligations [Member]
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Estimated fair value, Less than 12 months		2,108
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Aggregate Losses		(696)
Estimated fair value, 12 months or more	2,444	5,512
Available For Sale Securities Continuous Unrealized Loss Position Twelve Months Or More Aggregate Losses	(416)	(337)
Other Debt Securities [Member]
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Estimated fair value, Less than 12 months	13,142	14,017
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Aggregate Losses	(185)	(556)
Estimated fair value, 12 months or more	93,061	92,661
Available For Sale Securities Continuous Unrealized Loss Position Twelve Months Or More Aggregate Losses	(18,058)	(18,092)
Equity Securities [Member]
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Estimated fair value, Less than 12 months		2,138
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Aggregate Losses		$ (1,164)
Estimated fair value, 12 months or more	226
Available For Sale Securities Continuous Unrealized Loss Position Twelve Months Or More Aggregate Losses	$ (199)

Loans and leases and the allo42

Loans and leases and the allowance for credit losses - Outstanding Principal Balance and Carrying Amount of Loans that is Included in Consolidated Balance Sheet (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Outstanding principal and carrying value of acquired loans recorded at fair value
Outstanding principal balance	$ 2,631,165	$ 3,070,268
Carrying amount	2,219,379	2,596,545
Commercial, Financial, Leasing, etc. [Member]
Outstanding principal and carrying value of acquired loans recorded at fair value
Carrying amount	191,721	247,820
Commercial Real Estate [Member]
Outstanding principal and carrying value of acquired loans recorded at fair value
Carrying amount	775,816	961,828
Residential Real Estate [Member]
Outstanding principal and carrying value of acquired loans recorded at fair value
Carrying amount	407,774	453,360
Consumer [Member]
Outstanding principal and carrying value of acquired loans recorded at fair value
Carrying amount	$ 844,068	$ 933,537

Loans and Leases and the Allo43

Loans and Leases and the Allowance for Credit Losses - Additional Information (Detail) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Contractual principal and interest payments	$ 169	$ 198
Purchased impaired loans as a percentage of total assets	Less than 1%
Commercial mortgage loans held for sale	$ 320	308
Loan delinquent period	90 days
Minimum delinquency period for loan level collectability analysis consumer mortgage	150 days
Amount of foreclosed residential real estate property held	$ 43	44
Loans secured by residential real estate that were in the process of foreclosure	158
Residential Mortgage Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value of loans for which partial charge-off has been recognized	59	63
Mortgage loans, customer balance outstanding	23	27
Home Equity Loans and Lines of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value of loans for which partial charge-off has been recognized	20	18
Mortgage loans, customer balance outstanding	28	28
Residential Mortgage Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage loans held for sale	$ 479	$ 435

Loans and leases and the allo44

Loans and leases and the allowance for credit losses - Summary of Changes in Accretable Yield for Acquired Loans (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Purchased Impaired [Member]
Summary of changes in Accretable Yield for acquired loans
Balance at beginning of period	$ 71,422	$ 30,939	$ 76,518	$ 37,230
Interest income	(5,772)	(5,106)	(10,978)	(11,434)
Reclassifications from nonaccretable balance, net	11,974	249	12,084	286
Balance at end of period	77,624	26,082	77,624	26,082
Other Acquired [Member]
Summary of changes in Accretable Yield for acquired loans
Balance at beginning of period	357,895	485,162	397,379	538,633
Interest income	(40,024)	(43,452)	(81,301)	(96,085)
Reclassifications from nonaccretable balance, net	26,840	774	27,023	774
Other	278	8,486	1,888	7,648
Balance at end of period	$ 344,989	$ 450,970	$ 344,989	$ 450,970

Loans and Leases and the Allo45

Loans and Leases and the Allowance for Credit Losses - Summary of Current, Past Due and Nonaccrual Loans (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	$ 66,304,599	$ 64,785,780
30-89 Days past due	543,108	530,901
Purchased impaired	169,240	197,737
Nonaccrual	797,146	799,151
Loans and leases, net of unearned discount	68,131,252	66,668,956
Commercial, Financial, Leasing, etc. [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	19,852,368	19,228,265
30-89 Days past due	36,637	37,246
Purchased impaired	5,273	10,300
Nonaccrual	210,345	177,445
Loans and leases, net of unearned discount	20,111,028	19,461,292
Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	22,487,721	22,208,491
30-89 Days past due	156,567	118,704
Purchased impaired	52,115	51,312
Nonaccrual	167,520	141,600
Loans and leases, net of unearned discount	22,898,921	22,556,939
Residential Builder and Developer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	1,666,183	1,273,607
30-89 Days past due	4,233	11,827
Purchased impaired	73,628	98,347
Nonaccrual	56,854	71,517
Loans and leases, net of unearned discount	1,807,501	1,465,140
Other Commercial Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	3,642,229	3,484,932
30-89 Days past due	43,683	17,678
Purchased impaired	20,059	17,181
Nonaccrual	21,149	25,699
Loans and leases, net of unearned discount	3,736,066	3,545,490
Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	7,525,761	7,640,368
30-89 Days past due	197,893	226,932
Purchased impaired	15,804	18,223
Nonaccrual	164,721	180,275
Loans and leases, net of unearned discount	8,130,346	8,318,013
Residential Alt-A [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	234,859	249,810
30-89 Days past due	11,152	11,774
Nonaccrual	68,185	77,704
Loans and leases, net of unearned discount	314,196	339,288
Home Equity Lines and Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	5,765,082	5,859,378
30-89 Days past due	31,446	42,945
Purchased impaired	2,361	2,374
Nonaccrual	78,250	89,291
Loans and leases, net of unearned discount	5,889,510	6,021,884
Automobile [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	2,134,000	1,931,138
30-89 Days past due	29,906	30,500
Nonaccrual	15,156	17,578
Loans and leases, net of unearned discount	2,179,062	1,979,349
Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	2,996,396	2,909,791
30-89 Days past due	31,591	33,295
Nonaccrual	14,966	18,042
Loans and leases, net of unearned discount	3,064,622	2,981,561
Non-Acquired [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
90 Days or more past due and accruing	238,568	245,020
Non-Acquired [Member] | Commercial, Financial, Leasing, etc. [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
90 Days or more past due and accruing	4,777	1,805
Non-Acquired [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
90 Days or more past due and accruing	17,079	22,170
Non-Acquired [Member] | Residential Builder and Developer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
90 Days or more past due and accruing		492
Non-Acquired [Member] | Other Commercial Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
90 Days or more past due and accruing	6,112
Non-Acquired [Member] | Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
90 Days or more past due and accruing	207,195	216,489
Non-Acquired [Member] | Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
90 Days or more past due and accruing	3,405	4,064
Acquired [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
90 Days or more past due and accruing	78,591	110,367
Acquired [Member] | Commercial, Financial, Leasing, etc. [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
90 Days or more past due and accruing	1,628	6,231
Acquired [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
90 Days or more past due and accruing	17,919	14,662
Acquired [Member] | Residential Builder and Developer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
90 Days or more past due and accruing	6,603	9,350
Acquired [Member] | Other Commercial Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
90 Days or more past due and accruing	2,834
Acquired [Member] | Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
90 Days or more past due and accruing	18,972	35,726
Acquired [Member] | Home Equity Lines and Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
90 Days or more past due and accruing	12,371	27,896
Acquired [Member] | Automobile [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
90 Days or more past due and accruing		133
Acquired [Member] | Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
90 Days or more past due and accruing	$ 18,264	$ 16,369

Loans and Leases and the Allo46

Loans and Leases and the Allowance for Credit Losses - Changes in Allowance for Credit Losses (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	$ 921,373	$ 916,768	$ 919,562	$ 916,676
Provision for credit losses	30,000	30,000	68,000	62,000
Net charge-offs
Charge-offs	(32,962)	(41,838)	(80,438)	(89,277)
Recoveries	11,576	12,736	22,863	28,267
Net charge-offs	(21,386)	(29,102)	(57,575)	(61,010)
Ending balance	929,987	917,666	929,987	917,666
Commercial, Financial, Leasing, etc. [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	281,069	276,835	288,038	273,383
Provision for credit losses	9,737	25,556	11,179	38,154
Net charge-offs
Charge-offs	(7,728)	(14,142)	(20,078)	(28,951)
Recoveries	3,672	4,002	7,611	9,665
Net charge-offs	(4,056)	(10,140)	(12,467)	(19,286)
Ending balance	286,750	292,251	286,750	292,251
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	317,375	324,805	307,927	324,978
Provision for credit losses	(3,652)	(12,229)	11,890	(12,113)
Net charge-offs
Charge-offs	(3,470)	(2,814)	(10,149)	(6,300)
Recoveries	1,041	1,492	1,626	4,689
Net charge-offs	(2,429)	(1,322)	(8,523)	(1,611)
Ending balance	311,294	311,254	311,294	311,254
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	60,741	77,062	61,910	78,656
Provision for credit losses	1,624	(1,957)	2,584	2,271
Net charge-offs
Charge-offs	(3,309)	(5,478)	(6,427)	(12,931)
Recoveries	1,238	2,777	2,227	4,408
Net charge-offs	(2,071)	(2,701)	(4,200)	(8,523)
Ending balance	60,294	72,404	60,294	72,404
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	186,052	162,134	186,033	164,644
Provision for credit losses	21,016	18,676	40,590	32,817
Net charge-offs
Charge-offs	(18,455)	(19,404)	(43,784)	(41,095)
Recoveries	5,625	4,465	11,399	9,505
Net charge-offs	(12,830)	(14,939)	(32,385)	(31,590)
Ending balance	194,238	165,871	194,238	165,871
Unallocated [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	76,136	75,932	75,654	75,015
Provision for credit losses	1,275	(46)	1,757	871
Net charge-offs
Ending balance	$ 77,411	$ 75,886	$ 77,411	$ 75,886

Loans and Leases and the Allo47

Loans and Leases and the Allowance for Credit Losses - Impaired Loans and Leases (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Schedule Of Financial Receivables [Line Items]
Recorded investment with related allowance	$ 483,196	$ 498,575
Unpaid principal balance with related allowance	559,695	581,887
Related allowance	80,917	82,643
Recorded investment with no related allowance	301,152	263,880
Unpaid principal balance with no related allowance	418,860	371,907
Recorded investment	784,348	762,455
Unpaid principal balance	978,555	953,794
Related allowance	80,917	82,643
Commercial, Financial, Leasing, etc. [Member]
Schedule Of Financial Receivables [Line Items]
Recorded investment with related allowance	122,574	132,340
Unpaid principal balance with related allowance	147,028	165,146
Related allowance	31,098	31,779
Recorded investment with no related allowance	116,982	73,978
Unpaid principal balance with no related allowance	138,635	81,493
Recorded investment	239,556	206,318
Unpaid principal balance	285,663	246,639
Related allowance	31,098	31,779
Commercial Real Estate [Member]
Schedule Of Financial Receivables [Line Items]
Recorded investment with related allowance	105,064	83,955
Unpaid principal balance with related allowance	120,905	96,209
Related allowance	18,390	14,121
Recorded investment with no related allowance	72,094	66,777
Unpaid principal balance with no related allowance	79,541	78,943
Recorded investment	177,158	150,732
Unpaid principal balance	200,446	175,152
Related allowance	18,390	14,121
Residential Builder and Developer [Member]
Schedule Of Financial Receivables [Line Items]
Recorded investment with related allowance	7,808	17,632
Unpaid principal balance with related allowance	10,439	22,044
Related allowance	661	805
Recorded investment with no related allowance	53,843	58,820
Unpaid principal balance with no related allowance	94,700	96,722
Recorded investment	61,651	76,452
Unpaid principal balance	105,139	118,766
Related allowance	661	805
Other Commercial Construction [Member]
Schedule Of Financial Receivables [Line Items]
Recorded investment with related allowance	3,091	5,480
Unpaid principal balance with related allowance	4,542	6,484
Related allowance	514	900
Recorded investment with no related allowance	18,524	20,738
Unpaid principal balance with no related allowance	39,347	41,035
Recorded investment	21,615	26,218
Unpaid principal balance	43,889	47,519
Related allowance	514	900
Residential [Member]
Schedule Of Financial Receivables [Line Items]
Recorded investment with related allowance	84,241	88,970
Unpaid principal balance with related allowance	102,237	107,343
Related allowance	4,931	4,296
Recorded investment with no related allowance	16,174	16,815
Unpaid principal balance with no related allowance	26,120	26,750
Recorded investment	100,415	105,785
Unpaid principal balance	128,357	134,093
Related allowance	4,931	4,296
Residential Alt-A [Member]
Schedule Of Financial Receivables [Line Items]
Recorded investment with related allowance	94,752	101,137
Unpaid principal balance with related allowance	107,894	114,565
Related allowance	10,000	11,000
Recorded investment with no related allowance	23,535	26,752
Unpaid principal balance with no related allowance	40,517	46,964
Recorded investment	118,287	127,889
Unpaid principal balance	148,411	161,529
Related allowance	10,000	11,000
Home Equity Lines and Loans [Member]
Schedule Of Financial Receivables [Line Items]
Recorded investment with related allowance	21,235	19,771
Unpaid principal balance with related allowance	22,219	20,806
Related allowance	3,531	6,213
Recorded investment	21,235	19,771
Unpaid principal balance	22,219	20,806
Related allowance	3,531	6,213
Automobile [Member]
Schedule Of Financial Receivables [Line Items]
Recorded investment with related allowance	25,175	30,317
Unpaid principal balance with related allowance	25,175	30,317
Related allowance	6,334	8,070
Recorded investment	25,175	30,317
Unpaid principal balance	25,175	30,317
Related allowance	6,334	8,070
Other [Member]
Schedule Of Financial Receivables [Line Items]
Recorded investment with related allowance	19,256	18,973
Unpaid principal balance with related allowance	19,256	18,973
Related allowance	5,458	5,459
Recorded investment	19,256	18,973
Unpaid principal balance	19,256	18,973
Related allowance	$ 5,458	$ 5,459

Loans and Leases and the Allo48

Loans and Leases and the Allowance for Credit Losses - Interest Income Recognized on Loans (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment	$ 752,253	$ 855,403	$ 758,167	$ 875,130
Interest income recognized, Total	5,638	9,228	11,343	15,809
Interest income recognized, Cash basis	3,425	6,807	6,941	11,071
Commercial, Financial, Leasing, etc. [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment	221,952	150,625	218,285	142,466
Interest income recognized, Total	502	220	1,106	768
Interest income recognized, Cash basis	502	220	1,106	768
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment	153,105	207,633	153,088	196,529
Interest income recognized, Total	1,004	869	2,106	1,795
Interest income recognized, Cash basis	1,004	869	2,106	1,795
Residential Builder and Developer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment	66,334	91,614	69,742	96,434
Interest income recognized, Total	131	39	194	113
Interest income recognized, Cash basis	131	39	194	113
Other Commercial Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment	23,614	77,801	24,577	82,546
Interest income recognized, Total	168	356	223	1,443
Interest income recognized, Cash basis	168	356	223	1,443
Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment	101,560	119,133	103,025	146,651
Interest income recognized, Total	1,358	5,056	2,804	6,456
Interest income recognized, Cash basis	785	4,468	1,695	5,370
Residential Alt-A [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment	120,286	134,895	122,970	137,273
Interest income recognized, Total	1,650	1,733	3,260	3,359
Interest income recognized, Cash basis	697	660	1,344	1,219
Home Equity Lines and Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment	20,221	18,762	19,952	17,219
Interest income recognized, Total	224	200	425	321
Interest income recognized, Cash basis	65	72	113	101
Automobile [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment	26,123	36,631	27,568	38,007
Interest income recognized, Total	416	589	866	1,214
Interest income recognized, Cash basis	43	74	97	161
Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment	19,058	18,309	18,960	18,005
Interest income recognized, Total	185	166	359	340
Interest income recognized, Cash basis	$ 30	$ 49	$ 63	$ 101

Loans and leases and the allo49

Loans and leases and the allowance for credit losses - Summary of Loan Grades (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	$ 68,131,252	$ 66,668,956
Commercial, Financial, Leasing, etc. [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	20,111,028	19,461,292
Commercial, Financial, Leasing, etc. [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	19,079,109	18,695,440
Commercial, Financial, Leasing, etc. [Member] | Criticized Accrual [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	821,574	588,407
Commercial, Financial, Leasing, etc. [Member] | Criticized Nonaccrual [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	210,345	177,445
Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	22,898,921	22,556,939
Commercial [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	21,885,377	21,837,022
Commercial [Member] | Criticized Accrual [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	846,024	578,317
Commercial [Member] | Criticized Nonaccrual [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	167,520	141,600
Residential Builder and Developer [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	1,807,501	1,465,140
Residential Builder and Developer [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	1,690,496	1,347,778
Residential Builder and Developer [Member] | Criticized Accrual [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	60,151	45,845
Residential Builder and Developer [Member] | Criticized Nonaccrual [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	56,854	71,517
Other Commercial Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	3,736,066	3,545,490
Other Commercial Construction [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	3,549,397	3,347,522
Other Commercial Construction [Member] | Criticized Accrual [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	165,520	172,269
Other Commercial Construction [Member] | Criticized Nonaccrual [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	$ 21,149	$ 25,699

Loans and leases and the allo50

Loans and leases and the allowance for credit losses - Allocation of Allowance for Credit Losses on Basis of Company's Impairment Methodology (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	$ 80,621		$ 81,714
Allowance for credit losses	765,037		753,052
Allowance for credit losses	929,987	$ 921,373	919,562	$ 917,666	$ 916,768	$ 916,676
Purchased Impaired [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	6,918		9,142
Allocated [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	852,576		843,908
Unallocated [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	77,411	$ 76,136	75,654	$ 75,886	$ 75,932	$ 75,015
Commercial, Financial, Leasing, etc. [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	31,098		31,779
Allowance for credit losses	253,312		251,607
Commercial, Financial, Leasing, etc. [Member] | Purchased Impaired [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	2,340		4,652
Commercial, Financial, Leasing, etc. [Member] | Allocated [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	286,750		288,038
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	19,296		15,490
Allowance for credit losses	290,853		291,244
Commercial Real Estate [Member] | Purchased Impaired [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	1,145		1,193
Commercial Real Estate [Member] | Allocated [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	311,294		307,927
Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	14,904		14,703
Allowance for credit losses	43,428		45,061
Residential Real Estate [Member] | Purchased Impaired [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	1,962		2,146
Residential Real Estate [Member] | Allocated [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	60,294		61,910
Consumer Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	15,323		19,742
Allowance for credit losses	177,444		165,140
Consumer Loans [Member] | Purchased Impaired [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	1,471		1,151
Consumer Loans [Member] | Allocated [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	$ 194,238		$ 186,033

Loans and leases and the allo51

Loans and leases and the allowance for credit losses - Recorded Investment in Loans and Leases on Basis of Company's Impairment Methodology (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	$ 68,131,252	$ 66,668,956
Individually Evaluated for Impairment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	783,073	760,124
Collectively Evaluated for Impairment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	67,178,939	65,711,095
Purchased Impaired [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	169,240	197,737
Commercial, Financial, Leasing, etc. [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	20,111,028	19,461,292
Commercial, Financial, Leasing, etc. [Member] | Individually Evaluated for Impairment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	239,556	206,318
Commercial, Financial, Leasing, etc. [Member] | Collectively Evaluated for Impairment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	19,866,199	19,244,674
Commercial, Financial, Leasing, etc. [Member] | Purchased Impaired [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	5,273	10,300
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	28,442,488	27,567,569
Commercial Real Estate [Member] | Individually Evaluated for Impairment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	259,441	252,347
Commercial Real Estate [Member] | Collectively Evaluated for Impairment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	28,037,245	27,148,382
Commercial Real Estate [Member] | Purchased Impaired [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	145,802	166,840
Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	8,444,542	8,657,301
Residential Real Estate [Member] | Individually Evaluated for Impairment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	218,410	232,398
Residential Real Estate [Member] | Collectively Evaluated for Impairment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	8,210,328	8,406,680
Residential Real Estate [Member] | Purchased Impaired [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	15,804	18,223
Consumer Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	11,133,194	10,982,794
Consumer Loans [Member] | Individually Evaluated for Impairment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	65,666	69,061
Consumer Loans [Member] | Collectively Evaluated for Impairment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	11,065,167	10,911,359
Consumer Loans [Member] | Purchased Impaired [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net of unearned discount	$ 2,361	$ 2,374

Loans and leases and the allo52

Loans and leases and the allowance for credit losses - Loan Modification Activities that were Considered Troubled Debt Restructurings (Detail) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015USD ($)Modification	Jun. 30, 2014USD ($)Modification	Jun. 30, 2015USD ($)Modification	Jun. 30, 2014USD ($)Modification
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	218	193	368	436
Pre-modification, Recorded Investment	$ 96,065	$ 57,384	$ 116,197	$ 89,914
Post-modification, Recorded investment	95,987	57,297	113,989	89,797
Financial effects of modification, Recorded investment	(78)	(87)	(2,208)	(117)
Financial Effects of Modification, Interest	$ (692)	$ (1,011)	$ (849)	$ (1,880)
Principal Deferral [Member] | Commercial, Financial, Leasing, etc. [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	30	21	51	51
Pre-modification, Recorded Investment	$ 16,018	$ 4,414	$ 17,590	$ 19,368
Post-modification, Recorded investment	15,355	4,351	16,912	19,199
Financial effects of modification, Recorded investment	$ (663)	$ (63)	$ (678)	$ (169)
Principal Deferral [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	15	11	22	24
Pre-modification, Recorded Investment	$ 38,983	$ 8,327	$ 42,775	$ 15,371
Post-modification, Recorded investment	37,585	8,314	41,361	15,316
Financial effects of modification, Recorded investment	$ (1,398)	$ (13)	$ (1,414)	$ (55)
Principal Deferral [Member] | Residential Builder and Developer [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	1	1	2	1
Pre-modification, Recorded Investment	$ 9,252	$ 1,398	$ 10,650	$ 1,398
Post-modification, Recorded investment	9,200	$ 1,398	10,598	$ 1,398
Financial effects of modification, Recorded investment	$ (52)		$ (52)
Principal Deferral [Member] | Other Commercial Construction [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification		2		3
Pre-modification, Recorded Investment		$ 6,407		$ 6,558
Post-modification, Recorded investment		6,318		6,469
Financial effects of modification, Recorded investment		$ (89)		$ (89)
Principal Deferral [Member] | Residential [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	12	3	19	16
Pre-modification, Recorded Investment	$ 693	$ 142	$ 1,414	$ 1,744
Post-modification, Recorded investment	754	166	1,496	1,829
Financial effects of modification, Recorded investment	$ 61	$ 24	$ 82	$ 85
Principal Deferral [Member] | Residential Alt-A [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	1	3	1	5
Pre-modification, Recorded Investment	$ 161	$ 662	$ 161	$ 828
Post-modification, Recorded investment	$ 161	698	$ 161	900
Financial effects of modification, Recorded investment		$ 36		$ 72
Principal Deferral [Member] | Home Equity Lines and Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	1		2	3
Pre-modification, Recorded Investment	$ 1,198		$ 1,219	$ 280
Post-modification, Recorded investment	$ 1,198		$ 1,219	$ 280
Principal Deferral [Member] | Automobile [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	63	43	98	123
Pre-modification, Recorded Investment	$ 615	$ 603	$ 918	$ 1,596
Post-modification, Recorded investment	$ 615	$ 603	$ 918	$ 1,596
Principal Deferral [Member] | Other [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	27	7	49	15
Pre-modification, Recorded Investment	$ 770	$ 38	$ 1,066	$ 93
Post-modification, Recorded investment	$ 770	$ 38	$ 1,066	$ 93
Other [Member] | Commercial, Financial, Leasing, etc. [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	2	1	2	1
Pre-modification, Recorded Investment	$ 8,991	$ 19,593	$ 8,991	$ 19,593
Post-modification, Recorded investment	8,883	$ 19,593	8,883	$ 19,593
Financial effects of modification, Recorded investment	$ (108)		$ (108)
Other [Member] | Residential [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification				1
Pre-modification, Recorded Investment				$ 188
Post-modification, Recorded investment				$ 188
Other [Member] | Automobile [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	13	8	23	19
Pre-modification, Recorded Investment	$ 21	$ 47	$ 41	$ 108
Post-modification, Recorded investment	$ 21	$ 47	$ 41	$ 108
Other [Member] | Other [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	2		7	1
Pre-modification, Recorded Investment	$ 21		$ 80	$ 45
Post-modification, Recorded investment	$ 21		$ 80	$ 45
Combination of Concession Types [Member] | Commercial, Financial, Leasing, etc. [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	2	3	5	5
Pre-modification, Recorded Investment	$ 15,889	$ 9,795	$ 25,044	$ 9,836
Post-modification, Recorded investment	17,864	9,727	24,853	9,766
Financial effects of modification, Recorded investment	1,975	(68)	(191)	(70)
Financial Effects of Modification, Interest	$ (239)	$ (10)	$ (239)	$ (14)
Combination of Concession Types [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	1	1	5	2
Pre-modification, Recorded Investment	$ 436	$ 63	$ 2,082	$ 409
Post-modification, Recorded investment	436	61	2,073	462
Financial effects of modification, Recorded investment		(2)	(9)	53
Financial Effects of Modification, Interest	$ (53)	$ (9)	$ (105)	$ (113)
Combination of Concession Types [Member] | Residential [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	9	8	12	22
Pre-modification, Recorded Investment	$ 961	$ 923	$ 1,255	$ 3,111
Post-modification, Recorded investment	1,066	991	1,415	3,151
Financial effects of modification, Recorded investment	105	68	160	40
Financial Effects of Modification, Interest	$ (144)	$ (66)	$ (178)	$ (348)
Combination of Concession Types [Member] | Residential Alt-A [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	2	6	3	16
Pre-modification, Recorded Investment	$ 424	$ 1,006	$ 634	$ 2,752
Post-modification, Recorded investment	426	1,029	636	2,765
Financial effects of modification, Recorded investment	2	23	2	13
Financial Effects of Modification, Interest	$ (26)	$ (220)	$ (30)	$ (281)
Combination of Concession Types [Member] | Home Equity Lines and Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	14	21	19	36
Pre-modification, Recorded Investment	$ 1,356	$ 1,772	$ 1,552	$ 3,628
Post-modification, Recorded investment	1,356	1,772	1,552	3,628
Financial Effects of Modification, Interest	$ (212)	$ (204)	$ (225)	$ (376)
Combination of Concession Types [Member] | Automobile [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	9	23	17	46
Pre-modification, Recorded Investment	$ 138	$ 341	$ 222	$ 591
Post-modification, Recorded investment	138	341	222	591
Financial Effects of Modification, Interest	$ (4)	$ (36)	$ (11)	$ (62)
Combination of Concession Types [Member] | Other [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	10	19	23	33
Pre-modification, Recorded Investment	$ 43	$ 906	$ 267	$ 1,372
Post-modification, Recorded investment	43	906	267	1,372
Financial Effects of Modification, Interest	$ (7)	$ (276)	$ (32)	$ (464)
Interest Rate Reduction [Member] | Commercial, Financial, Leasing, etc. [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification			1
Pre-modification, Recorded Investment			$ 99
Post-modification, Recorded investment			99
Financial Effects of Modification, Interest			$ (19)
Interest Rate Reduction [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification		1		1
Pre-modification, Recorded Investment		$ 255		$ 255
Post-modification, Recorded investment		252		252
Financial effects of modification, Recorded investment		(3)		(3)
Financial Effects of Modification, Interest		$ (48)		$ (48)
Interest Rate Reduction [Member] | Residential [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification				1
Pre-modification, Recorded Investment				$ 98
Post-modification, Recorded investment				104
Financial effects of modification, Recorded investment				6
Financial Effects of Modification, Interest				$ (32)
Interest Rate Reduction [Member] | Home Equity Lines and Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification		5		5
Pre-modification, Recorded Investment		$ 341		$ 341
Post-modification, Recorded investment		341		341
Financial Effects of Modification, Interest		$ (76)		$ (76)
Interest Rate Reduction [Member] | Automobile [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	4	3	7	3
Pre-modification, Recorded Investment	$ 95	$ 60	$ 137	$ 60
Post-modification, Recorded investment	95	60	137	60
Financial Effects of Modification, Interest	$ (7)	$ (3)	$ (10)	$ (3)
Interest Rate Reduction [Member] | Other [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification		3		3
Pre-modification, Recorded Investment		$ 291		$ 291
Post-modification, Recorded investment		291		291
Financial Effects of Modification, Interest		$ (63)		$ (63)

Borrowings - Additional Informa

Borrowings - Additional Information (Detail) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015	Feb. 28, 2015	Dec. 31, 2014	Feb. 27, 2014
Schedule Of Borrowings [Line Items]
Interest rate of debt instrument				8.50%
Junior subordinated debentures	$ 513
Agreements to repurchase securities	1,400		$ 1,400
Collateral posted	$ 1,500		$ 1,500
Senior Notes Due 2020 [Member]
Schedule Of Borrowings [Line Items]
Interest rate of debt instrument		2.10%
Fixed rate senior notes issued		$ 750
Senior Notes Due 2025 [Member]
Schedule Of Borrowings [Line Items]
Interest rate of debt instrument		2.90%
Fixed rate senior notes issued		$ 750
Senior Notes [Member]
Schedule Of Borrowings [Line Items]
Fixed rate senior notes issued		$ 1,500
Junior Subordinated Debt [Member]
Schedule Of Borrowings [Line Items]
Debt Maturity, Start Year	Jan. 1, 2027
Debt Maturity, End Year	Dec. 31, 2033
Junior subordinated debentures redeemed	$ 323
Trust Preferred Securities Subject to Mandatory Redemption [Member]
Schedule Of Borrowings [Line Items]
Junior subordinated debentures				$ 350

Shareholders' Equity - Addition

Shareholders' Equity - Additional Information (Detail) - $ / shares	Jun. 30, 2015	Dec. 31, 2014
Class of Stock [Line Items]
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, par value	$ 1	$ 1
Warrant [Member] | Series D Fixed Rate Non-Cumulative Perpetual Preferred Stock [Member]
Class of Stock [Line Items]
Exercise price of each class of warrants or rights outstanding	$ 518.96	$ 518.96
Warrant to purchase common stock	95,383	95,383

Shareholders' Equity - Issued a

Shareholders' Equity - Issued and Outstanding Preferred Stock (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Class of Stock [Line Items]
Carrying value	$ 1,231,500	$ 1,231,500
Series A Fixed Rate Cumulative Perpetual Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, shares issued	230,000	230,000
Preferred stock, shares outstanding	230,000	230,000
Carrying value	$ 230,000	$ 230,000
Series C Fixed Rate Cumulative Perpetual Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, shares issued	151,500	151,500
Preferred stock, shares outstanding	151,500	151,500
Carrying value	$ 151,500	$ 151,500
Series D Fixed Rate Non-Cumulative Perpetual Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, shares issued	50,000	50,000
Preferred stock, shares outstanding	50,000	50,000
Carrying value	$ 500,000	$ 500,000
Series E Fixed-to-Floating Rate Non-Cumulative Perpetual Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, shares issued	350,000	350,000
Preferred stock, shares outstanding	350,000	350,000
Carrying value	$ 350,000	$ 350,000

Shareholders' Equity - Issued56

Shareholders' Equity - Issued and Outstanding Preferred Stock (Parenthetical) (Detail) - $ / shares	6 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Series A Fixed Rate Cumulative Perpetual Preferred Stock [Member]
Class of Stock [Line Items]
Liquidation preference	$ 1,000	$ 1,000
Preferred stock dividend rate	6.375%
Exercise price of each class of warrants or rights outstanding	$ 73.86
Warrants and rights outstanding	719,175	721,490
Warrants, year of expiration	2,018
Series C Fixed Rate Cumulative Perpetual Preferred Stock [Member]
Class of Stock [Line Items]
Liquidation preference	$ 1,000	$ 1,000
Series D Fixed Rate Non-Cumulative Perpetual Preferred Stock [Member]
Class of Stock [Line Items]
Liquidation preference	$ 10,000	10,000
Preferred stock dividend rate	6.875%
Preferred Stock, Redemption Feature, Redemption Term	90 days
Preferred shares redemption date	Jun. 15, 2016
Series E Fixed-to-Floating Rate Non-Cumulative Perpetual Preferred Stock [Member]
Class of Stock [Line Items]
Liquidation preference	$ 1,000	$ 1,000
Preferred stock dividend rate	6.45%
Preferred Stock, Redemption Feature, Redemption Term	90 days
Preferred shares redemption date	Feb. 15, 2024
Date of change in the dividend rate	Feb. 14, 2024
London Interbank offered rate plus basis points	3.61%

Pension Plans and Other Postr57

Pension Plans and Other Postretirement Benefits - Net Periodic Benefit Cost for Defined Benefit Plans (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 5,832	$ 5,160	$ 11,832	$ 10,260
Interest cost on projected benefit obligation	17,732	17,331	35,507	34,581
Expected return on plan assets	(23,476)	(22,859)	(47,051)	(45,784)
Amortization of prior service credit	(1,478)	(1,626)	(3,003)	(3,276)
Amortization of net actuarial loss	11,237	3,897	22,412	7,247
Net periodic benefit cost	9,847	1,903	19,697	3,028
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	174	152	374	302
Interest cost on projected benefit obligation	652	714	1,302	1,389
Amortization of prior service credit	(329)	(329)	(679)	(679)
Amortization of net actuarial loss	28		53
Net periodic benefit cost	$ 525	$ 537	$ 1,050	$ 1,012

Pension Plans and Other Postr58

Pension Plans and Other Postretirement Benefits - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Compensation and Retirement Disclosure [Abstract]
Defined contribution pension and retirement savings plans total expense	$ 13,346,000	$ 12,673,000	$ 30,096,000	$ 28,405,000

Earnings Per Common Share - Com

Earnings Per Common Share - Computations of Basic Earnings Per Common Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income available to common shareholders:
Net income	$ 286,688	$ 284,336	$ 528,301	$ 513,353
Less: Preferred stock dividends	(20,317)	(20,443)	(40,635)	(35,117)
Net income available to common equity	266,371	263,893	487,666	478,236
Less: Income attributable to unvested stock-based compensation awards	(2,900)	(3,213)	(5,371)	(5,832)
Net income available to common shareholders	$ 263,471	$ 260,680	$ 482,295	$ 472,404
Weighted-average shares outstanding:
Common shares outstanding (including common stock issuable) and unvested stock-based compensation awards	133,818	132,473	133,680	132,139
Less: Unvested stock-based compensation awards	(1,462)	(1,617)	(1,477)	(1,603)
Weighted-average shares outstanding	132,356	130,856	132,203	130,536
Basic earnings per common share	$ 1.99	$ 1.99	$ 3.65	$ 3.62

Earnings Per Common Share - C60

Earnings Per Common Share - Computations of Diluted Earnings Per Common Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Earnings Per Share [Abstract]
Net income available to common equity	$ 266,371	$ 263,893	$ 487,666	$ 478,236
Less: Income attributable to unvested stock-based compensation awards	(2,890)	(3,198)	(5,353)	(5,807)
Net income available to common shareholders	$ 263,481	$ 260,695	$ 482,313	$ 472,429
Adjusted weighted-average shares outstanding:
Common and unvested stock-based compensation awards	133,818	132,473	133,680	132,139
Less: Unvested stock-based compensation awards	(1,462)	(1,617)	(1,477)	(1,603)
Plus: Incremental shares from assumed conversion of stock-based compensation awards and warrants to purchase common stock	760	972	741	943
Adjusted weighted-average shares outstanding	133,116	131,828	132,944	131,479
Diluted earnings per common share	$ 1.98	$ 1.98	$ 3.63	$ 3.59

Earnings Per Common Share - Add

Earnings Per Common Share - Additional Information (Detail) - shares shares in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Earnings Per Share [Abstract]
Antidilutive securities excluded from computation of earnings per share	1.6	1.7	2.1	2.4

Comprehensive Income - Componen

Comprehensive Income - Components of Other Comprehensive Income (Loss) and Amounts Reclassified from Accumulated Other Comprehensive Income (Loss) to Net Income (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			$ (297,843)	$ (105,797)
Unrealized holding gains, net			(79,932)	167,606
Foreign currency translation adjustment			(779)	479
Unrealized Gains (losses) on cash flow hedges			1,453	(1,170)
Total other comprehensive income before reclassifications			(79,258)	166,915
Accretion of unrealized holding losses on held-to-maturity ("HTM") securities			1,589	1,703
Losses realized in net income			108
Accretion of net gain on terminated cash flow hedges			(63)
Amortization of prior service credit			(3,682)	(3,955)
Amortization of actuarial losses			22,465	7,247
Total reclassifications			20,417	4,995
Total gain (loss) during the period			(58,841)	171,910
Ending balance	$ (356,684)	$ 66,113	(356,684)	66,113
Beginning balance			116,849	41,638
Unrealized holding gains, net			31,617	(65,774)
Foreign currency translation adjustment			261	(166)
Unrealized Gains (losses) on cash flow hedges			(568)	459
Total other comprehensive income before reclassifications			31,310	(65,481)
Accretion of unrealized holding losses on held-to-maturity ("HTM") securities			(621)	(669)
Losses realized in net income			(40)
Accretion of net gain on terminated cash flow hedges			25
Amortization of prior service credit			1,640	1,552
Amortization of actuarial losses			(9,981)	(2,845)
Total reclassifications			(8,977)	(1,962)
Total gain (loss) during the period			22,333	(67,443)
Ending balance	139,182	(25,805)	139,182	(25,805)
Beginning balance			(180,994)	(64,159)
Unrealized holding gains, net			(48,315)	101,832
Foreign currency translation adjustment	1,866	449	(518)	313
Unrealized Gains (losses) on cash flow hedges			885	(711)
Total other comprehensive income before reclassifications			(47,948)	101,434
Accretion of unrealized holding losses on held-to-maturity ("HTM") securities			968	1,034
Losses realized in net income			68
Accretion of net gain on terminated cash flow hedges			(38)
Amortization of prior service credit			(2,042)	(2,403)
Amortization of actuarial losses			12,484	4,402
Total reclassifications			11,440	3,033
Total gain (loss) during the period			(36,508)	104,467
Ending balance	(217,502)	40,308	(217,502)	40,308
Investment Securities With OTTI [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			7,438	37,255
Unrealized holding gains, net			5,670	10,842
Total other comprehensive income before reclassifications			5,670	10,842
Accretion of unrealized holding losses on held-to-maturity ("HTM") securities				1
Total reclassifications				1
Total gain (loss) during the period			5,670	10,843
Ending balance	13,108	48,098	13,108	48,098
Investment Securities All Other [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			201,828	18,450
Unrealized holding gains, net			(85,602)	156,764
Total other comprehensive income before reclassifications			(85,602)	156,764
Accretion of unrealized holding losses on held-to-maturity ("HTM") securities			1,589	1,702
Losses realized in net income			108
Total reclassifications			1,697	1,702
Total gain (loss) during the period			(83,905)	158,466
Ending balance	117,923	176,916	117,923	176,916
Defined Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			(503,027)	(161,617)
Amortization of prior service credit			(3,682)	(3,955)
Amortization of actuarial losses			22,465	7,247
Total reclassifications			18,783	3,292
Total gain (loss) during the period			18,783	3,292
Ending balance	(484,244)	(158,325)	(484,244)	(158,325)
Beginning balance			(305,589)
Total gain (loss) during the period			10,442
Ending balance	(295,147)		(295,147)
Other [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			(4,082)	115
Foreign currency translation adjustment			(779)	479
Unrealized Gains (losses) on cash flow hedges			1,453	(1,170)
Total other comprehensive income before reclassifications			674	(691)
Accretion of net gain on terminated cash flow hedges			(63)
Total reclassifications			(63)
Total gain (loss) during the period			611	(691)
Ending balance	$ (3,471)	$ (576)	$ (3,471)	$ (576)

Comprehensive Income - Accumula

Comprehensive Income - Accumulated Other Comprehensive Income (Loss), Net (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ (180,994)	$ (64,159)
Net gain (loss) during period	(36,508)	104,467
Ending balance	(217,502)	$ 40,308
Investment Securities With OTTI [Member] | Investment Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	4,518
Net gain (loss) during period	3,471
Ending balance	7,989
Investment Securities All Other [Member] | Investment Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	122,683
Net gain (loss) during period	(50,750)
Ending balance	71,933
Defined Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(305,589)
Net gain (loss) during period	10,442
Ending balance	(295,147)
Accumulated Other Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(2,606)
Net gain (loss) during period	329
Ending balance	$ (2,277)

Derivative Financial Instrume64

Derivative Financial Instruments - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Derivative [Line Items]
Net unrealized pre-tax gains related to hedged loans held for sale, commitments to originate loans for sale and commitments to sell loans	$ 29,000,000		$ 29,000,000		$ 28,000,000
Aggregate fair value of derivative financial instruments in a liability position	124,000,000		124,000,000		161,000,000
Net liability positions with counterparties	72,000,000		72,000,000		103,000,000
Post collateral requirements relating to positions	65,000,000		65,000,000		90,000,000
Aggregate fair value of derivative financial instruments in asset position	89,000,000		89,000,000		104,000,000
Net asset positions with counterparties	37,000,000		37,000,000		46,000,000
Counterparties posted collateral relating to positions	37,000,000		37,000,000		46,000,000
Clearinghouse Credit Facilities [Member]
Derivative [Line Items]
Post collateral requirements relating to positions	70,000,000		70,000,000		61,000,000
Aggregate fair value of derivative financial instruments in a net liability position	35,000,000		35,000,000		35,000,000
Credit Risk Derivative [Member]
Derivative [Line Items]
Aggregate fair value of derivative financial instruments in a net liability position	14,000,000		14,000,000
Fair value of collateral already posted for derivative financial instruments	8,000,000		8,000,000
Fair value of additional collateral to be posted for derivative financial instruments	6,000,000		6,000,000
Interest Rate Swap Agreements [Member]
Derivative [Line Items]
Increase in net interest income due to interest rate swap agreements	11,000,000	$ 12,000,000	22,000,000	$ 23,000,000
Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amounts of derivative contracts entered into for trading account purposes	17,200,000,000		17,200,000,000		17,600,000,000
Foreign Currency and Other Option and Futures Contracts [Member]
Derivative [Line Items]
Notional amounts of derivative contracts entered into for trading account purposes	$ 1,600,000,000		$ 1,600,000,000		$ 1,300,000,000

Derivative Financial Instrume65

Derivative Financial Instruments - Information about Interest Rate Swap Agreements (Detail) - Fixed Rate Long-Term Borrowings [Member] - Fair Value Hedges [Member] - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Derivative [Line Items]
Notional Amount	$ 1,400,000,000	$ 1,400,000,000
Average Maturity (in years)	2 years 2 months 12 days	2 years 8 months 12 days
Weighted-Average Rate, Fixed	4.42%	4.42%
Weighted-Average Rate, Variable	1.24%	1.19%

Derivative Financial Instrume66

Derivative Financial Instruments - Information about Fair Values of Derivative Instruments in Consolidated Balance Sheet (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Asset derivatives, Fair value	$ 309,527	$ 338,855
Liability derivatives, Fair value	176,570	212,059
Derivatives Not Designated and Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Asset derivatives, Fair value	233,876	264,876
Liability derivatives, Fair value	175,991	207,842
Fair Value Hedges [Member] | Derivatives Designated and Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Asset derivatives, Fair value	75,651	73,979
Liability derivatives, Fair value	579	4,217
Interest Rate Swap Agreements [Member] | Fair Value Hedges [Member] | Derivatives Designated and Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Asset derivatives, Fair value	63,501	73,251
Commitments to Sell Real Estate Loans [Member] | Derivatives Not Designated and Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Asset derivatives, Fair value	2,645	754
Liability derivatives, Fair value	1,946	4,330
Commitments to Sell Real Estate Loans [Member] | Fair Value Hedges [Member] | Derivatives Designated and Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Asset derivatives, Fair value	12,150	728
Liability derivatives, Fair value	579	4,217
Mortgage-Related Commitments to Originate Real Estate Loans for Sale [Member] | Derivatives Not Designated and Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Asset derivatives, Fair value	12,755	17,396
Liability derivatives, Fair value	1,549	49
Interest Rate Contracts [Member] | Derivatives Not Designated and Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Asset derivatives, Fair value	202,052	215,614
Liability derivatives, Fair value	158,670	173,513
Foreign Exchange and Other Option and Futures Contracts [Member] | Derivatives Not Designated and Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Asset derivatives, Fair value	16,424	31,112
Liability derivatives, Fair value	$ 13,826	$ 29,950

Derivative Financial Instrume67

Derivative Financial Instruments - Information about Fair Values of Derivative Instruments in Consolidated Statement of Income (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives not designated as hedging instruments, Derivatives	$ 1,061	$ 598	$ 1,554	$ (4,734)
Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives not designated as hedging instruments, Derivatives	1,772	1,384	2,432	1,082
Foreign Exchange and Other Option and Futures Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives not designated as hedging instruments, Derivatives	(711)	(786)	(878)	(5,816)
Interest Rate Swap Agreements [Member] | Fixed Rate Long-Term Borrowings [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives in fair value hedging relationships, Derivatives	(9,354)	(1,675)	(9,750)	(9,835)
Derivatives in fair value hedging relationships, Hedged item	$ 8,952	$ 1,358	$ 9,113	$ 9,278

Variable Interest Entities an68

Variable Interest Entities and Asset Securitizations - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Variable Interest Entity Disclosure [Abstract]
Residential mortgage loans securitized with Ginnie Mae	$ 23,000,000	$ 46,000,000	$ 36,000,000	$ 75,000,000
Carrying value of loans in the Securitization trusts	88,000,000		88,000,000		$ 98,000,000
Combined outstanding principal amount of mortgage-backed securities issued by qualified special purpose trust held by unrelated parties	14,000,000		14,000,000		15,000,000
Other assets for its "investment" in the common securities recognized by the company of various trusts	24,000,000		24,000,000		34,000,000
Total assets of real estate partnerships in which the company invested	1,200,000,000		1,200,000,000		1,200,000,000
Maximum exposure to loss of investments in real estate partnerships	295,000,000		295,000,000		243,000,000
Unfunded commitments included in company's maximum exposure to loss of investments in real estate partnerships	76,000,000		76,000,000		$ 56,000,000
Investments amortized to income tax expense	11,000,000	14,000,000	21,000,000	26,000,000
Tax credits and other tax benefits recognized	$ 15,000,000	$ 18,000,000	$ 29,000,000	$ 35,000,000

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015USD ($)Source	Jun. 30, 2014USD ($)	Jun. 30, 2015USD ($)Source	Jun. 30, 2014USD ($)	Dec. 31, 2014USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of independent pricing sources used to value privately issued mortgage-backed securities valued with internal modeling | Source	2		2
Securities issued by financial institutions and other entities backed by trust preferred securities at cost	$ 28		$ 28		$ 30
Fair value of securities issued by financial institutions and other entities backed by trust preferred securities	50		50		50
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Change in fair value of nonrecurring fair value measured loans for charge-offs and impairment reserves	34	$ 32	42	$ 47
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans measured at fair value on nonrecurring basis	147	212	147	212	173
Assets taken in foreclosure of defaulted loans measured at fair value on a nonrecurring basis	13	15	13	15
Fair Value, Measurements, Nonrecurring [Member] | Significant Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans measured at fair value on nonrecurring basis	89	129	89	129	94
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans measured at fair value on nonrecurring basis	$ 58	$ 83	$ 58	$ 83	$ 79
Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount margin over LIBOR			4.00%
Discount rates for fair value estimations			10.00%
Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount margin over LIBOR			10.00%
Discount rates for fair value estimations			90.00%
Weighted Average [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount margin over LIBOR			7.00%

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Estimated Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	$ 277,009	$ 308,175
Investment securities	11,250,877	9,156,932
Real estate loans held for sale	798,404	742,249
Other assets	91,051	92,129
Total assets	12,417,341	10,299,485
Trading account liabilities	172,496	203,464
Other liabilities	4,074	8,596
Total liabilities	176,570	212,060
U.S. Treasury and Federal Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	198,718	161,947
Obligations of States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	7,504	8,198
Government Issued or Guaranteed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	10,771,892	8,731,123
Privately Issued Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	88	103
Collateralized Debt Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	50,483	50,316
Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	121,954	121,488
Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	100,238	83,757
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	49,052	51,416
Investment securities	75,427	64,841
Total assets	124,479	116,257
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	75,427	64,841
Significant Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	227,957	256,759
Investment securities	11,124,879	9,041,672
Real estate loans held for sale	798,404	742,249
Other assets	78,296	74,733
Total assets	12,229,536	10,115,413
Trading account liabilities	172,496	203,464
Other liabilities	2,525	8,547
Total liabilities	175,021	212,011
Significant Observable Inputs (Level 2) [Member] | U.S. Treasury and Federal Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	198,718	161,947
Significant Observable Inputs (Level 2) [Member] | Obligations of States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	7,504	8,198
Significant Observable Inputs (Level 2) [Member] | Government Issued or Guaranteed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	10,771,892	8,731,123
Significant Observable Inputs (Level 2) [Member] | Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	121,954	121,488
Significant Observable Inputs (Level 2) [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	24,811	18,916
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	50,571	50,419
Other assets	12,755	17,396
Total assets	63,326	67,815
Other liabilities	1,549	49
Total liabilities	1,549	49
Significant Unobservable Inputs (Level 3) [Member] | Privately Issued Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	88	103
Significant Unobservable Inputs (Level 3) [Member] | Collateralized Debt Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	$ 50,483	$ 50,316

Fair Value Measurements - Chang

Fair Value Measurements - Changes in Level 3 Assets and Liabilities Measured at Estimated Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Other Assets and Other Liabilities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	$ 26,230	$ 12,589	$ 17,347	$ 3,941
Total gains realized/unrealized:
Included in earnings	16,132	31,517	45,902	53,900
Sales	0	0
Transfers in and/or out of Level 3	(31,156)	(22,083)	(52,043)	(35,818)
Ending Balance	11,206	22,023	11,206	22,023
Changes in unrealized gains included in earnings related to assets still held at end of period	6,330	20,215	8,763	24,099
Privately Issued [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	95	696	103	1,850
Total gains realized/unrealized:
Included in other comprehensive income		205		272
Sales	0	0
Settlements	(7)	(782)	(15)	(2,003)
Ending Balance	88	119	88	119
Collateralized Debt Obligations [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	47,278	61,768	50,316	63,083
Total gains realized/unrealized:
Included in other comprehensive income	7,629	4,486	5,625	9,132
Sales	0	0
Settlements	(4,424)	(10,054)	(5,458)	(16,015)
Ending Balance	$ 50,483	$ 56,200	$ 50,483	$ 56,200

Fair Value Measurements - Quant

Fair Value Measurements - Quantitative Information Related to Significant Unobservable Inputs (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014	Mar. 31, 2015	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013
Privately Issued [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair value	$ 88	$ 103	$ 95	$ 119	$ 696	$ 1,850
Collateralized Debt Obligations [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair value	50,483	50,316	47,278	56,200	61,768	63,083
Other Assets and Other Liabilities [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair value	11,206	17,347	$ 26,230	$ 22,023	$ 12,589	$ 3,941
Discounted Cash Flows [Member] | Collateralized Debt Obligations [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair value	$ 50,483	$ 50,316
Loss severity	100.00%	100.00%
Discounted Cash Flows [Member] | Collateralized Debt Obligations [Member] | Weighted Average [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Probability of default	37.00%	36.00%
Discounted Cash Flows [Member] | Collateralized Debt Obligations [Member] | Minimum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Probability of default	12.00%	12.00%
Discounted Cash Flows [Member] | Collateralized Debt Obligations [Member] | Maximum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Probability of default	57.00%	57.00%
Discounted Cash Flows [Member] | Other Assets and Other Liabilities [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair value	$ 11,206	$ 17,347
Discounted Cash Flows [Member] | Other Assets and Other Liabilities [Member] | Weighted Average [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Commitment expirations	24.00%	17.00%
Discounted Cash Flows [Member] | Other Assets and Other Liabilities [Member] | Minimum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Commitment expirations	0.00%	0.00%
Discounted Cash Flows [Member] | Other Assets and Other Liabilities [Member] | Maximum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Commitment expirations	95.00%	96.00%
Two Independent Pricing Quotes [Member] | Privately Issued [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair value	$ 88	$ 103

Fair Value Measurements - Carry

Fair Value Measurements - Carrying Amounts and Estimated Fair Value for Financial Instrument Assets (Liabilities) (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013
Financial assets:
Cash and cash equivalents	$ 1,350,858		$ 1,373,357	$ 1,917,436		$ 1,672,934
Interest-bearing deposits at banks	4,045,852		6,470,867
Trading account assets	277,009		308,175
Loans and leases:
Allowance for credit losses	(929,987)	$ (921,373)	(919,562)	$ (917,666)	$ (916,768)	$ (916,676)
Loans and leases, net	67,201,265		65,749,394
Financial liabilities:
Noninterest-bearing deposits	(27,674,588)		(26,947,880)
Time deposits	(2,901,636)		(3,063,973)
Deposits at Cayman Islands office	(167,441)		(176,582)
Short-term borrowings	(153,299)		(192,676)
Long-term borrowings	(10,175,912)		(9,006,959)
Trading account liabilities	(172,496)		(203,464)
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets:
Cash and cash equivalents	1,291,501		1,296,923
Trading account assets	49,052		51,416
Investment securities	75,427		64,841
Significant Observable Inputs (Level 2) [Member]
Financial assets:
Cash and cash equivalents	59,357		76,434
Interest-bearing deposits at banks	4,045,852		6,470,867
Trading account assets	227,957		256,759
Investment securities	14,479,134		12,750,396
Loans and leases:
Commercial real estate loans	319,877		307,667
Residential real estate loans	5,024,771		5,189,086
Loans and leases, net	5,344,648		5,496,753
Accrued interest receivable	228,126		227,348
Financial liabilities:
Noninterest-bearing deposits	(27,674,588)		(26,947,880)
Savings deposits and NOW accounts	(41,885,954)		(43,393,618)
Time deposits	(2,921,070)		(3,086,126)
Deposits at Cayman Islands office	(167,441)		(176,582)
Short-term borrowings	(153,299)		(192,676)
Long-term borrowings	(10,219,668)		(9,139,789)
Accrued interest payable	(72,062)		(63,372)
Trading account liabilities	(172,496)		(203,464)
Other financial instruments:
Commitments to sell real estate loans	12,270		(7,065)
Interest rate swap agreements used for interest rate risk management	63,501		73,251
Significant Unobservable Inputs (Level 3) [Member]
Financial assets:
Investment securities	208,338		208,719
Loans and leases:
Commercial loans and leases	19,822,748		19,188,574
Commercial real estate loans	28,001,323		27,180,151
Residential real estate loans	3,440,275		3,539,970
Consumer loans	11,014,334		10,909,623
Loans and leases, net	62,278,680		60,818,318
Other financial instruments:
Commitments to originate real estate loans for sale	11,206		17,347
Other credit-related commitments	(121,385)		(119,079)
Carrying Amount [Member]
Financial assets:
Cash and cash equivalents	1,350,858		1,373,357
Interest-bearing deposits at banks	4,045,852		6,470,867
Trading account assets	277,009		308,175
Investment securities	14,751,637		12,993,542
Loans and leases:
Commercial loans and leases	20,111,028		19,461,292
Commercial real estate loans	28,442,488		27,567,569
Residential real estate loans	8,444,542		8,657,301
Consumer loans	11,133,194		10,982,794
Allowance for credit losses	(929,987)		(919,562)
Loans and leases, net	67,201,265		65,749,394
Accrued interest receivable	228,126		227,348
Financial liabilities:
Noninterest-bearing deposits	(27,674,588)		(26,947,880)
Savings deposits and NOW accounts	(41,885,954)		(43,393,618)
Time deposits	(2,901,636)		(3,063,973)
Deposits at Cayman Islands office	(167,441)		(176,582)
Short-term borrowings	(153,299)		(192,676)
Long-term borrowings	(10,175,912)		(9,006,959)
Accrued interest payable	(72,062)		(63,372)
Trading account liabilities	(172,496)		(203,464)
Other financial instruments:
Commitments to originate real estate loans for sale	11,206		17,347
Commitments to sell real estate loans	12,270		(7,065)
Other credit-related commitments	(121,385)		(119,079)
Interest rate swap agreements used for interest rate risk management	63,501		73,251
Estimate Fair Value [Member]
Financial assets:
Cash and cash equivalents	1,350,858		1,373,357
Interest-bearing deposits at banks	4,045,852		6,470,867
Trading account assets	277,009		308,175
Investment securities	14,762,899		13,023,956
Loans and leases:
Commercial loans and leases	19,822,748		19,188,574
Commercial real estate loans	28,321,200		27,487,818
Residential real estate loans	8,465,046		8,729,056
Consumer loans	11,014,334		10,909,623
Loans and leases, net	67,623,328		66,315,071
Accrued interest receivable	228,126		227,348
Financial liabilities:
Noninterest-bearing deposits	(27,674,588)		(26,947,880)
Savings deposits and NOW accounts	(41,885,954)		(43,393,618)
Time deposits	(2,921,070)		(3,086,126)
Deposits at Cayman Islands office	(167,441)		(176,582)
Short-term borrowings	(153,299)		(192,676)
Long-term borrowings	(10,219,668)		(9,139,789)
Accrued interest payable	(72,062)		(63,372)
Trading account liabilities	(172,496)		(203,464)
Other financial instruments:
Commitments to originate real estate loans for sale	11,206		17,347
Commitments to sell real estate loans	12,270		(7,065)
Other credit-related commitments	(121,385)		(119,079)
Interest rate swap agreements used for interest rate risk management	$ 63,501		$ 73,251

Commitments and Contingencies -

Commitments and Contingencies - Company's Significant Commitments (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Commitments to extend credit
Home equity lines of credit	$ 5,612,243	$ 6,194,516
Commercial real estate loans to be sold	104,832	212,257
Other commercial real estate and construction	5,601,820	4,834,699
Residential real estate loans to be sold	671,670	432,352
Other residential real estate	719,788	524,399
Commercial and other	11,439,086	11,080,856
Standby letters of credit	3,531,401	3,706,888
Commercial letters of credit	42,858	46,965
Financial guarantees and indemnification contracts	2,795,007	2,490,050
Commitments to sell real estate loans	$ 1,354,654	$ 1,237,294

Commitments and Contingencies75

Commitments and Contingencies - Additional Information (Detail) - USD ($)	Jun. 30, 2015	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Maximum credit risk for recourse associated with loans sold under Federal National Mortgage Association Delegated Underwriting and Servicing program	$ 2,500,000,000	$ 2,400,000,000
Range of reasonably possible losses, minimum	0
Range of reasonably possible losses, maximum	$ 40,000,000

Segment Information - Summary o

Segment Information - Summary of Prior Period Financial Information Restated (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Segment Reporting Information [Line Items]
Net income (loss)	$ 286,688	$ 284,336	$ 528,301	$ 513,353
Business Banking [Member]
Segment Reporting Information [Line Items]
Net income (loss)	25,354	23,752	50,165	48,725
Commercial Banking [Member]
Segment Reporting Information [Line Items]
Net income (loss)	108,081	104,091	204,504	202,932
Commercial Real Estate [Member]
Segment Reporting Information [Line Items]
Net income (loss)	79,751	75,728	159,837	148,280
Discretionary Portfolio [Member]
Segment Reporting Information [Line Items]
Net income (loss)	10,756	15,043	16,710	26,403
Residential Mortgage Banking [Member]
Segment Reporting Information [Line Items]
Net income (loss)	27,699	26,649	59,664	45,229
Retail Banking [Member]
Segment Reporting Information [Line Items]
Net income (loss)	68,806	72,973	137,694	142,007
All Other [Member]
Segment Reporting Information [Line Items]
Net income (loss)	$ (33,759)	(33,900)	$ (100,273)	(100,223)
Net Income (Loss) as Previously Reported [Member]
Segment Reporting Information [Line Items]
Net income (loss)		284,336		513,353
Net Income (Loss) as Previously Reported [Member] | Business Banking [Member]
Segment Reporting Information [Line Items]
Net income (loss)		27,760		56,358
Net Income (Loss) as Previously Reported [Member] | Commercial Banking [Member]
Segment Reporting Information [Line Items]
Net income (loss)		105,358		205,123
Net Income (Loss) as Previously Reported [Member] | Commercial Real Estate [Member]
Segment Reporting Information [Line Items]
Net income (loss)		77,526		152,087
Net Income (Loss) as Previously Reported [Member] | Discretionary Portfolio [Member]
Segment Reporting Information [Line Items]
Net income (loss)		14,980		26,259
Net Income (Loss) as Previously Reported [Member] | Residential Mortgage Banking [Member]
Segment Reporting Information [Line Items]
Net income (loss)		27,712		47,123
Net Income (Loss) as Previously Reported [Member] | Retail Banking [Member]
Segment Reporting Information [Line Items]
Net income (loss)		32,034		61,745
Net Income (Loss) as Previously Reported [Member] | All Other [Member]
Segment Reporting Information [Line Items]
Net income (loss)		(1,034)		(35,342)
Impact of Changes [Member] | Business Banking [Member]
Segment Reporting Information [Line Items]
Net income (loss)		(4,008)		(7,633)
Impact of Changes [Member] | Commercial Banking [Member]
Segment Reporting Information [Line Items]
Net income (loss)		(1,267)		(2,191)
Impact of Changes [Member] | Commercial Real Estate [Member]
Segment Reporting Information [Line Items]
Net income (loss)		(1,798)		(3,807)
Impact of Changes [Member] | Discretionary Portfolio [Member]
Segment Reporting Information [Line Items]
Net income (loss)		63		144
Impact of Changes [Member] | Residential Mortgage Banking [Member]
Segment Reporting Information [Line Items]
Net income (loss)		(1,063)		(1,894)
Impact of Changes [Member] | Retail Banking [Member]
Segment Reporting Information [Line Items]
Net income (loss)		40,939		80,262
Impact of Changes [Member] | All Other [Member]
Segment Reporting Information [Line Items]
Net income (loss)		$ (32,866)		$ (64,881)

Segment Information - Informati

Segment Information - Information about Company's Segments (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Segment Reporting Information [Line Items]
Net income (loss)	$ 286,688	$ 284,336	$ 528,301	$ 513,353
Business Banking [Member]
Segment Reporting Information [Line Items]
Net income (loss)	25,354	23,752	50,165	48,725
Commercial Banking [Member]
Segment Reporting Information [Line Items]
Net income (loss)	108,081	104,091	204,504	202,932
Commercial Real Estate [Member]
Segment Reporting Information [Line Items]
Net income (loss)	79,751	75,728	159,837	148,280
Discretionary Portfolio [Member]
Segment Reporting Information [Line Items]
Net income (loss)	10,756	15,043	16,710	26,403
Residential Mortgage Banking [Member]
Segment Reporting Information [Line Items]
Net income (loss)	27,699	26,649	59,664	45,229
Retail Banking [Member]
Segment Reporting Information [Line Items]
Net income (loss)	68,806	72,973	137,694	142,007
All Other [Member]
Segment Reporting Information [Line Items]
Net income (loss)	(33,759)	(33,900)	(100,273)	(100,223)
Operating Segments [Member]
Segment Reporting Information [Line Items]
Total revenues	1,180,155	1,125,526	2,279,946	2,202,066
Operating Segments [Member] | Business Banking [Member]
Segment Reporting Information [Line Items]
Total revenues	111,131	112,734	219,691	224,504
Operating Segments [Member] | Commercial Banking [Member]
Segment Reporting Information [Line Items]
Total revenues	257,257	252,347	503,838	501,696
Operating Segments [Member] | Commercial Real Estate [Member]
Segment Reporting Information [Line Items]
Total revenues	178,949	164,262	342,269	321,585
Operating Segments [Member] | Discretionary Portfolio [Member]
Segment Reporting Information [Line Items]
Total revenues	20,477	29,912	35,951	54,569
Operating Segments [Member] | Residential Mortgage Banking [Member]
Segment Reporting Information [Line Items]
Total revenues	112,029	109,837	223,487	203,602
Operating Segments [Member] | Retail Banking [Member]
Segment Reporting Information [Line Items]
Total revenues	305,573	311,554	605,964	618,334
Operating Segments [Member] | All Other [Member]
Segment Reporting Information [Line Items]
Total revenues	194,739	144,880	348,746	277,776
Intersegment Activity Eliminated in Consolidated Totals [Member] | Business Banking [Member]
Segment Reporting Information [Line Items]
Total revenues	1,122	1,220	2,167	2,277
Intersegment Activity Eliminated in Consolidated Totals [Member] | Commercial Banking [Member]
Segment Reporting Information [Line Items]
Total revenues	1,099	1,356	2,184	2,553
Intersegment Activity Eliminated in Consolidated Totals [Member] | Commercial Real Estate [Member]
Segment Reporting Information [Line Items]
Total revenues	427	525	509	873
Intersegment Activity Eliminated in Consolidated Totals [Member] | Discretionary Portfolio [Member]
Segment Reporting Information [Line Items]
Total revenues	(5,376)	(5,282)	(10,819)	(10,321)
Intersegment Activity Eliminated in Consolidated Totals [Member] | Residential Mortgage Banking [Member]
Segment Reporting Information [Line Items]
Total revenues	12,436	11,772	23,823	21,520
Intersegment Activity Eliminated in Consolidated Totals [Member] | Retail Banking [Member]
Segment Reporting Information [Line Items]
Total revenues	3,259	3,897	6,396	7,402
Intersegment Activity Eliminated in Consolidated Totals [Member] | All Other [Member]
Segment Reporting Information [Line Items]
Total revenues	$ (12,967)	$ (13,488)	$ (24,260)	$ (24,304)

Segment Information - Summary78

Segment Information - Summary of Segment Information (Detail) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014
Sales Information [Line Items]
Average Assets	$ 96,750	$ 92,143	$ 88,278
Business Banking [Member]
Sales Information [Line Items]
Average Assets	5,313	5,281	5,286
Commercial Banking [Member]
Sales Information [Line Items]
Average Assets	23,997	22,892	22,742
Commercial Real Estate [Member]
Sales Information [Line Items]
Average Assets	18,191	17,113	16,878
Discretionary Portfolio [Member]
Sales Information [Line Items]
Average Assets	23,029	20,798	19,417
Residential Mortgage Banking [Member]
Sales Information [Line Items]
Average Assets	3,413	3,333	3,226
Retail Banking [Member]
Sales Information [Line Items]
Average Assets	10,830	10,449	10,229
All Other [Member]
Sales Information [Line Items]
Average Assets	$ 11,977	$ 12,277	$ 10,500

Segment Information - Summary79

Segment Information - Summary of Segment Information (Parenthetical) (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Segment Reporting [Abstract]
Taxable-equivalent adjustment	$ 6,020,000	$ 5,849,000	$ 11,858,000	$ 11,794,000

Relationship with Bayview Len80

Relationship with Bayview Lending Group LLC and Bayview Financial Holdings, L.P. - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Bayview Lending Group and Bayview Financial [Member]
Schedule of Equity Method Investments [Line Items]
Outstanding principal balances of mortgage servicing rights	$ 4,500		$ 4,500		$ 4,800
Revenues from servicing	$ 6	$ 7	$ 12	$ 14
Bayview Lending Group [Member]
Schedule of Equity Method Investments [Line Items]
Minority interest in Bayview Lending Group LLC	20.00%		20.00%
Carrying value of minority interest investment in Bayview Lending Group LLC	$ 38		$ 38
Bayview Financial [Member]
Schedule of Equity Method Investments [Line Items]
Revenues from servicing	30	$ 27	65	$ 53
Outstanding principal balances of residential mortgage loans from Bayview Financial	41,500		41,500		41,300
Investment securities in held-to-maturity portfolio securitized by Bayview Financial	$ 192		$ 192		$ 202

Sale of Trust Accounts - Additi

Sale of Trust Accounts - Additional Information (Detail) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		6 Months Ended	12 Months Ended
	Apr. 30, 2015	Mar. 31, 2015	Jun. 30, 2014	Jun. 30, 2014	Dec. 31, 2014
Discontinued Operations and Disposal Groups [Abstract]
Gain on sale of business net of tax	$ 23
Gain on sale of business before tax	45
Goodwill recorded	$ 11
Revenue on sale of business		$ 9	$ 10	$ 18	$ 34