Commerce Bancshares (CBSH) 10-Q 7 Nov 17 2017 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Nov. 01, 2017
Document And Entity Information [Abstract]
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2,017
Document Type	10-Q
Amendment Flag	false
Document Fiscal Period Focus	Q3
Entity Registrant Name	COMMERCE BANCSHARES INC /MO/
Current Fiscal Year End Date	--12-31
Entity Central Index Key	22,356
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		101,632,724

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
ASSETS
Loans	$ 13,745,492	$ 13,412,736
Allowance for loan losses	(157,832)	(155,932)
Net loans	13,587,660	13,256,804
Loans held for sale	17,337	14,456
Investment securities:
Available for sale securities	9,109,287	9,649,203
Trading	24,605	22,225
Non-marketable	99,268	99,558
Total investment securities	9,233,160	9,770,986
Federal funds sold and short-term securities purchased under agreements to resell	32,630	15,470
Long-term securities purchased under agreements to resell	700,000	725,000
Interest earning deposits with banks	105,422	272,275
Cash and due from banks	461,724	494,690
Land, buildings and equipment, net	335,348	337,705
Goodwill	138,921	138,921
Other intangible assets, net	7,388	6,709
Other assets	359,551	608,408
Total assets	24,979,141	25,641,424
Deposits:
Non-interest bearing	7,536,127	7,429,398
Savings, interest checking and money market	11,091,200	11,430,789
Time open and C.D.'s of less than $100,000	657,891	713,075
Time open and C.D.'s, $100,000 or More	1,158,555	1,527,833
Total deposits	20,443,773	21,101,095
Federal funds purchased and securities sold under agreements to repurchase	1,408,984	1,723,905
Other Borrowings	102,553	102,049
Other liabilities	319,354	213,243
Total liabilities	22,274,664	23,140,292
Commerce Bancshares, Inc. stockholders' equity:
Preferred stock	144,784	144,784
Common stock	510,015	510,015
Capital surplus	1,548,318	1,552,454
Retained earnings	440,261	292,849
Treasury stock, at cost	(9,895)	(15,294)
Accumulated other comprehensive income	67,061	10,975
Total Commerce Bancshares, Inc. stockholders' equity	2,700,544	2,495,783
Non-controlling interest	3,933	5,349
Total equity	2,704,477	2,501,132
Total liabilities and equity	$ 24,979,141	$ 25,641,424

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Mortgage Loans:
Mortgages Held-for-sale, Fair Value Disclosure	$ 11,320,000	$ 9,263,000
Investment Securities:
Available-for-sale Securities Pledged as Collateral	$ 667,199,000	$ 568,553,000
Stockholders' Equity:
Preferred stock, par value	$ 1	$ 1
Preferred stock, shares authorized	2,000,000	2,000,000
Preferred stock, shares issued	6,000	6,000
Common stock, par value	$ 5	$ 5
Common Stock, Shares Authorized	120,000,000	120,000,000
Common stock, shares issued	102,003,046	102,003,046
Treasury stock, shares	197,566	364,711

Consolidated Statements Of Inco

Consolidated Statements Of Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017		Sep. 30, 2016
INTEREST INCOME
Interest and fees on loans	$ 138,827	$ 123,750	$ 401,423		$ 364,234
Interest and fees on loans held for sale	287	334	746		1,161
Interest on investment securities	50,585	51,661	160,825		155,250
Interest on federal funds sold and short-term securities purchased under agreements to resell	78	20	138		63
Interest on long-term securities purchased under agreements to resell	3,805	3,328	11,282		10,157
Interest on deposits with banks	662	268	1,421		689
Total interest income	194,244	179,361	575,835		531,554
INTEREST EXPENSE
Savings, interest checking and money market	4,441	3,619	12,673		10,651
Time open and C.D.'s of less than $100,000	676	683	1,994		2,134
Time open and C.D.'s of $100,000 and over	2,784	2,186	8,369		6,519
Interest on federal funds purchased and securities sold under agreements to repurchase	2,846	724	6,423		2,337
Interest on other borrowings	906	906	2,705		3,066
Total interest expense	11,653	8,118	32,164		24,707
Net interest income	182,591	171,243	543,671		506,847
Provision for loan losses	10,704	7,263	32,590		25,918
Net interest income after provision for loan losses	171,887	163,980	511,081		480,929
NON-INTEREST INCOME
Bank card transaction fees	44,521	47,006	132,724		136,541
Trust fees	34,620	30,951	99,754		90,435
Deposit account charges and other fees	22,659	22,241	67,462		64,260
Capital market fees	1,755	2,751	6,253		7,976
Consumer brokerage services	3,679	3,375	11,054		10,375
Loan fees and sales	3,590	3,123	10,849		8,829
Other	11,418	9,872	34,296		36,497
Total non-interest income	122,242	119,319	362,392		354,913
INVESTMENT SECURITIES GAINS (LOSSES), NET
Investment securities gains (losses), net	(3,037)	(1,965)	(2,158)	[1]	(3,704)	[1]
NON-INTEREST EXPENSE
Salaries and employee benefits	111,382	107,004	332,580		318,671
Net occupancy	11,459	12,366	34,332		34,761
Equipment	4,491	4,842	13,876		14,257
Supplies and communication	5,517	5,968	16,672		18,490
Data processing and software	22,700	23,663	69,153		69,332
Marketing	4,676	4,399	12,388		12,601
Deposit insurance	3,479	3,576	10,542		9,884
Other	20,868	19,424	66,453		57,808
Total non-interest expense	184,572	181,242	555,996		535,804
Income before income taxes	106,520	100,092	315,319		296,334
Less income taxes	32,294	30,942	90,402		91,854
Net income	74,226	69,150	224,917		204,480
Less non-controlling interest expense (income)	(338)	605	(111)		668
Net income attributable to Commerce Bancshares, Inc.	74,564	68,545	225,028		203,812
Preferred Stock Dividends	2,250	2,250	6,750		6,750
Net Income (Loss) Available to Common Stockholders	$ 72,314	$ 66,295	$ 218,278		$ 197,062
Net income per common share - basic	$ 0.71	$ 0.65	$ 2.14		$ 1.94
Net income per common share - diluted	$ 0.71	$ 0.65	$ 2.14		$ 1.93
[1]	Available for sale and non-marketable securities

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 74,226	$ 69,150	$ 224,917	$ 204,480
Other comprehensive income (loss)
Net unrealized gains (losses) on securities for which a portion of an other-than-temporary impairment has been recorded in earnings	286	46	457	(352)
Net unrealized gains (losses) on other securities	24,356	(13,747)	54,599	87,887
Pension loss amortization	349	359	1,030	1,077
Other comprehensive income (loss), net of tax	24,991	(13,342)	56,086	88,612
Comprehensive income	99,217	55,808	281,003	293,092
Non-controlling interest expense (income)	(338)	605	(111)	668
Comprehensive income attributable to Commerce Bancshares, Inc	$ 99,555	$ 55,203	$ 281,114	$ 292,424

Consolidated Statements Of Chan

Consolidated Statements Of Changes In Equity - USD ($) $ in Thousands	Total	Preferred Stock [Member]	Common Stock [Member]	Capital Surplus [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Non-Controlling Interest [Member]
Balance at Dec. 31, 2015	$ 2,367,418	$ 144,784	$ 489,862	$ 1,337,677	$ 383,313	$ (26,116)	$ 32,470	$ 5,428
Net income	204,480				203,812			668
Other comprehensive income (loss)	88,612						88,612
Distributions to non-controlling interest	(704)							(704)
Purchase of treasury stock	(38,476)					(38,476)
Issuance of stock under purchase and equity compensation plans	(3)			(14,057)		14,054
Excess (net) tax benefit related to equity compensation plans	2,629			2,629
Stock-based compensation	8,901			8,901
Cash dividends per share, Common Stock, Cash	(65,294)				(65,294)
Dividends per share, Preferred Stock, Cash	(6,750)				(6,750)
Balance at Sep. 30, 2016	2,560,813	144,784	489,862	1,335,150	515,081	(50,538)	121,082	5,392
Balance at Dec. 31, 2016	2,501,132	144,784	510,015	1,552,454	292,849	(15,294)	10,975	5,349
Adoption of ASU 2016-09	1,297			3,441	(2,144)
Net income	224,917				225,028			(111)
Other comprehensive income (loss)	56,086						56,086
Distributions to non-controlling interest	(1,305)							(1,305)
Purchase of treasury stock	(11,320)					(11,320)
Issuance of stock under purchase and equity compensation plans	(7)			(16,726)		16,719
Stock-based compensation	9,149			9,149
Cash dividends per share, Common Stock, Cash	(68,722)				(68,722)
Dividends per share, Preferred Stock, Cash	(6,750)				(6,750)
Balance at Sep. 30, 2017	$ 2,704,477	$ 144,784	$ 510,015	$ 1,548,318	$ 440,261	$ (9,895)	$ 67,061	$ 3,933

Consolidated Statements Of Cha7

Consolidated Statements Of Changes In Equity (Parenthetical) - $ / shares	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Statement of Stockholders' Equity [Abstract]
Common Stock, Dividends, per share, cash paid	$ 0.675	$ 0.643
Preferred Stock, Dividends, per share, cash paid	$ 1.125	$ 1.125

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016
OPERATING ACTIVITIES:
Net income		$ 224,917	$ 204,480
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses		32,590	25,918
Provision for depreciation and amortization		29,521	30,997
Amortization of investment security premiums, net		28,173	23,357
Investment securities gains (losses), net	[1]	2,158	3,704
Net gains on sales of loans held for sale		(6,200)	(4,924)
Origination of loans held for sale		(162,552)	(115,768)
Proceeds from sales and repayments of held for sale		164,588	117,746
Net (increase) decrease in trading securities, excluding unsettled transactions		7,234	77,262
Stock-based compensation		9,149	8,901
(Increase) decrease in interest receivable		(3,757)	(331)
Increase (decrease) in interest payable		(223)	269
Increase (decrease) in income taxes payable		201	1,787
Other changes, net		8,511	(24,602)
Net cash provided by (used in) operating activities		334,310	348,796
INVESTING ACTIVITIES:
Proceeds from sales of investment securities	[1]	369,036	7,946
Proceeds from maturities/pay downs of investment securities	[1]	1,384,993	1,659,778
Purchases of investment securities	[1]	(1,072,782)	(1,080,003)
Net (increase) decrease in loans		(364,765)	(817,886)
Payments for Securities Purchased under Agreements to Resell		(75,000)	0
Repayments of long-term securities purchased under agreements to resell		100,000	150,000
Purchases of land, buildings and equipment		(22,853)	(18,479)
Sales of land, buildings and equipment		2,570	5,831
Net cash provided by (used in) investing activities		321,199	(92,813)
FINANCING ACTIVITIES:
Net increase (decrease) in non-interest bearing, savings, interest checking and money market deposits		(12,490)	280,495
Net increase (decrease) in time open and C.D.'s		(424,462)	14,510
Net increase (decrease) in federal funds purchased and short-term securities sold under agreements to repurchase		(314,921)	(473,661)
Repayment of long-term borrowings		(218)	(3,872)
Additional long-term borrowings		0	1,469
Proceeds from Short-term Debt		722	0
Purchases of treasury stock		(11,320)	(38,476)
Issuance of stock under equity compensation plans		(7)	(3)
Cash dividends paid on common stock		(68,722)	(65,294)
Cash dividends paid on preferred stock		(6,750)	(6,750)
Net cash provided by (used in) financing activities		(838,168)	(291,582)
Increase (decrease) in cash and cash equivalents		(182,659)	(35,599)
Cash and cash equivalents at beginning of year		782,435	502,719
Cash and cash equivalents at end of period		599,776	467,120
Supplemental Cash Flow Information:
Income tax payments, net		87,449	88,531
Interest paid on deposits and borrowings		32,387	24,438
Loans transferred to foreclosed real estate		1,166	1,031
Transfer of loans held for investment to held for sale		$ 0	$ 42,688
[1]	Available for sale and non-marketable securities

Principles Of Consolidation And

Principles Of Consolidation And Presentation	9 Months Ended
	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Principles Of Consolidation And Presentation	Principles of Consolidation and Presentation The accompanying consolidated financial statements include the accounts of Commerce Bancshares, Inc. and all majority-owned subsidiaries (the Company). Most of the Company's operations are conducted by its subsidiary bank, Commerce Bank (the Bank). The consolidated financial statements in this report have not been audited by an independent registered public accounting firm, but in the opinion of management, all adjustments necessary to present fairly the financial position and the results of operations for the interim periods have been made. All such adjustments are of a normal recurring nature. All significant intercompany accounts and transactions have been eliminated. Certain reclassifications were made to 2016 data to conform to current year presentation. In preparing the consolidated financial statements, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities as of the date of the balance sheet and revenues and expenses for the period. Actual results could differ significantly from those estimates. Management has evaluated subsequent events for potential recognition or disclosure. The results of operations for the three and nine month periods ended September 30, 2017 are not necessarily indicative of results to be attained for the full year or any other interim period. The consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (GAAP) for interim financial information and with the instructions to Form 10-Q adopted by the Securities and Exchange Commission. Accordingly, the financial statements do not include all of the information and footnotes required by GAAP for complete financial statements and should be read in conjunction with the Company's most recent Annual Report on Form 10-K, containing the latest audited consolidated financial statements and notes thereto.

Loans And Allowance For Loan Lo

Loans And Allowance For Loan Losses	9 Months Ended
	Sep. 30, 2017
Loans And Allowance For Loan Losses [Abstract]
Loans And Allowance For Loan Losses	Loans and Allowance for Loan Losses Major classifications within the Company’s held for investment loan portfolio at September 30, 2017 and December 31, 2016 are as follows: (In thousands) September 30, 2017 December 31, 2016 Commercial: Business $ 4,834,037 $ 4,776,365 Real estate – construction and land 921,609 791,236 Real estate – business 2,700,174 2,643,374 Personal Banking: Real estate – personal 2,029,302 2,010,397 Consumer 2,113,438 1,990,801 Revolving home equity 391,308 413,634 Consumer credit card 752,379 776,465 Overdrafts 3,245 10,464 Total loans $ 13,745,492 $ 13,412,736 At September 30, 2017 , loans of $3.8 billion were pledged at the Federal Home Loan Bank as collateral for borrowings and letters of credit obtained to secure public deposits. Additional loans of $1.7 billion were pledged at the Federal Reserve Bank as collateral for discount window borrowings. Allowance for loan losses A summary of the activity in the allowance for loan losses during the three and nine months ended September 30, 2017 and 2016 , respectively, follows: For the Three Months Ended September 30 For the Nine Months Ended September 30 (In thousands) Commercial Personal Banking Total Commercial Personal Banking Total Balance at beginning of period $ 92,739 $ 65,093 $ 157,832 $ 91,361 $ 64,571 $ 155,932 Provision 24 10,680 10,704 1,026 31,564 32,590 Deductions: Loans charged off 378 13,592 13,970 1,455 39,337 40,792 Less recoveries on loans 651 2,615 3,266 2,104 7,998 10,102 Net loan charge-offs (recoveries) (273 ) 10,977 10,704 (649 ) 31,339 30,690 Balance September 30, 2017 $ 93,036 $ 64,796 $ 157,832 $ 93,036 $ 64,796 $ 157,832 Balance at beginning of period $ 89,198 $ 64,634 $ 153,832 $ 82,086 $ 69,446 $ 151,532 Provision (1,411 ) 8,674 7,263 4,309 21,609 25,918 Deductions: Loans charged off 291 11,872 12,163 2,465 35,633 38,098 Less recoveries on loans 2,759 2,841 5,600 6,325 8,855 15,180 Net loan charge-offs (recoveries) (2,468 ) 9,031 6,563 (3,860 ) 26,778 22,918 Balance September 30, 2016 $ 90,255 $ 64,277 $ 154,532 $ 90,255 $ 64,277 $ 154,532 The following table shows the balance in the allowance for loan losses and the related loan balance at September 30, 2017 and December 31, 2016 , disaggregated on the basis of impairment methodology. Impaired loans evaluated under ASC 310-10-35 include loans on non-accrual status, which are individually evaluated for impairment, and other impaired loans discussed below, which are deemed to have similar risk characteristics and are collectively evaluated. All other loans are collectively evaluated for impairment under ASC 450-20. Impaired Loans All Other Loans (In thousands) Allowance for Loan Losses Loans Outstanding Allowance for Loan Losses Loans Outstanding September 30, 2017 Commercial $ 1,789 $ 55,969 $ 91,247 $ 8,399,851 Personal Banking 1,322 23,571 63,474 5,266,101 Total $ 3,111 $ 79,540 $ 154,721 $ 13,665,952 December 31, 2016 Commercial $ 1,817 $ 44,795 $ 89,544 $ 8,166,180 Personal Banking 1,292 19,737 63,279 5,182,024 Total $ 3,109 $ 64,532 $ 152,823 $ 13,348,204 Impaired loans The table below shows the Company’s investment in impaired loans at September 30, 2017 and December 31, 2016 . These loans consist of all loans on non-accrual status and other restructured loans whose terms have been modified and classified as troubled debt restructurings. These restructured loans are performing in accordance with their modified terms, and because the Company believes it probable that all amounts due under the modified terms of the agreements will be collected, interest on these loans is being recognized on an accrual basis. They are discussed further in the "Troubled debt restructurings" section on page 14. (In thousands) Sept. 30, 2017 Dec. 31, 2016 Non-accrual loans $ 13,640 $ 14,283 Restructured loans (accruing) 65,900 50,249 Total impaired loans $ 79,540 $ 64,532 The following table provides additional information about impaired loans held by the Company at September 30, 2017 and December 31, 2016 , segregated between loans for which an allowance for credit losses has been provided and loans for which no allowance has been provided. (In thousands) Recorded Investment Unpaid Principal Balance Related Allowance September 30, 2017 With no related allowance recorded: Business $ 6,196 $ 9,725 $ — Real estate – business 587 587 — Consumer 1,023 1,047 — $ 7,806 $ 11,359 $ — With an allowance recorded: Business $ 35,708 $ 36,219 $ 1,141 Real estate – construction and land 1,367 1,595 37 Real estate – business 12,111 13,319 611 Real estate – personal 9,723 12,537 607 Consumer 5,232 5,271 52 Revolving home equity 578 578 5 Consumer credit card 7,015 7,015 658 $ 71,734 $ 76,534 $ 3,111 Total $ 79,540 $ 87,893 $ 3,111 December 31, 2016 With no related allowance recorded: Business $ 7,375 $ 10,470 $ — Real estate – construction and land 557 752 — $ 7,932 $ 11,222 $ — With an allowance recorded: Business $ 29,924 $ 31,795 $ 1,318 Real estate – construction and land 69 72 3 Real estate – business 6,870 8,072 496 Real estate – personal 6,394 9,199 642 Consumer 5,281 5,281 57 Revolving home equity 584 584 1 Consumer credit card 7,478 7,478 592 $ 56,600 $ 62,481 $ 3,109 Total $ 64,532 $ 73,703 $ 3,109 Total average impaired loans for the three and nine month periods ended September 30, 2017 and 2016 , respectively, are shown in the table below. (In thousands) Commercial Personal Banking Total Average Impaired Loans: For the three months ended September 30, 2017 Non-accrual loans $ 8,938 $ 4,238 $ 13,176 Restructured loans (accruing) 42,930 18,691 61,621 Total $ 51,868 $ 22,929 $ 74,797 For the nine months ended September 30, 2017 Non-accrual loans $ 9,800 $ 4,098 $ 13,898 Restructured loans (accruing) 36,567 16,901 53,468 Total $ 46,367 $ 20,999 $ 67,366 For the three months ended September 30, 2016 Non-accrual loans $ 15,106 $ 3,928 $ 19,034 Restructured loans (accruing) 31,372 17,082 48,454 Total $ 46,478 $ 21,010 $ 67,488 For the nine months ended September 30, 2016 Non-accrual loans $ 19,387 $ 4,336 $ 23,723 Restructured loans (accruing) 29,117 17,359 46,476 Total $ 48,504 $ 21,695 $ 70,199 The table below shows interest income recognized during the three and nine month periods ended September 30, 2017 and 2016 , respectively, for impaired loans held at the end of each period. This interest all relates to accruing restructured loans, as discussed in the "Troubled debt restructurings" section on page 14. For the Three Months Ended September 30 For the Nine Months Ended September 30 (In thousands) 2017 2016 2017 2016 Interest income recognized on impaired loans: Business $ 473 $ 277 $ 1,418 $ 830 Real estate – construction and land 10 2 30 7 Real estate – business 118 42 354 126 Real estate – personal 104 39 311 118 Consumer 79 89 236 267 Revolving home equity 7 7 20 22 Consumer credit card 162 174 486 522 Total $ 953 $ 630 $ 2,855 $ 1,892 Delinquent and non-accrual loans The following table provides aging information on the Company’s past due and accruing loans, in addition to the balances of loans on non-accrual status, at September 30, 2017 and December 31, 2016 . (In thousands) Current or Less Than 30 Days Past Due 30 – 89 Days Past Due 90 Days Past Due and Still Accruing Non-accrual Total September 30, 2017 Commercial: Business $ 4,823,779 $ 2,630 $ 807 $ 6,821 $ 4,834,037 Real estate – construction and land 917,128 3,913 35 533 921,609 Real estate – business 2,688,625 8,580 623 2,346 2,700,174 Personal Banking: Real estate – personal 2,013,632 11,141 1,666 2,863 2,029,302 Consumer 2,082,203 27,450 2,708 1,077 2,113,438 Revolving home equity 388,346 1,530 1,432 — 391,308 Consumer credit card 734,215 8,971 9,193 — 752,379 Overdrafts 2,933 312 — — 3,245 Total $ 13,650,861 $ 64,527 $ 16,464 $ 13,640 $ 13,745,492 December 31, 2016 Commercial: Business $ 4,763,274 $ 3,735 $ 674 $ 8,682 $ 4,776,365 Real estate – construction and land 789,633 1,039 — 564 791,236 Real estate – business 2,639,586 2,154 — 1,634 2,643,374 Personal Banking: Real estate – personal 1,995,724 9,162 2,108 3,403 2,010,397 Consumer 1,957,358 29,783 3,660 — 1,990,801 Revolving home equity 411,483 1,032 1,119 — 413,634 Consumer credit card 757,443 10,187 8,835 — 776,465 Overdrafts 10,014 450 — — 10,464 Total $ 13,324,515 $ 57,542 $ 16,396 $ 14,283 $ 13,412,736 Credit quality The following table provides information about the credit quality of the Commercial loan portfolio, using the Company’s internal rating system as an indicator. The internal rating system is a series of grades reflecting management’s risk assessment, based on its analysis of the borrower’s financial condition. The “pass” category consists of a range of loan grades that reflect increasing, though still acceptable, risk. Movement of risk through the various grade levels in the “pass” category is monitored for early identification of credit deterioration. The “special mention” rating is applied to loans where the borrower exhibits negative financial trends due to borrower specific or systemic conditions that, if left uncorrected, threaten its capacity to meet its debt obligations. The borrower is believed to have sufficient financial flexibility to react to and resolve its negative financial situation. It is a transitional grade that is closely monitored for improvement or deterioration. The “substandard” rating is applied to loans where the borrower exhibits well-defined weaknesses that jeopardize its continued performance and are of a severity that the distinct possibility of default exists. Loans are placed on “non-accrual” when management does not expect to collect payments consistent with acceptable and agreed upon terms of repayment. Commercial Loans (In thousands) Business Real Estate-Construction Real Estate- Business Total September 30, 2017 Pass $ 4,593,958 $ 915,279 $ 2,586,349 $ 8,095,586 Special mention 123,549 2,527 57,319 183,395 Substandard 109,709 3,270 54,160 167,139 Non-accrual 6,821 533 2,346 9,700 Total $ 4,834,037 $ 921,609 $ 2,700,174 $ 8,455,820 December 31, 2016 Pass $ 4,607,553 $ 788,778 $ 2,543,348 $ 7,939,679 Special mention 116,642 722 45,479 162,843 Substandard 43,488 1,172 52,913 97,573 Non-accrual 8,682 564 1,634 10,880 Total $ 4,776,365 $ 791,236 $ 2,643,374 $ 8,210,975 The credit quality of Personal Banking loans is monitored primarily on the basis of aging/delinquency, and this information is provided in the table in the above "Delinquent and non-accrual loans" section. In addition, FICO scores are obtained and updated on a quarterly basis for most of the loans in the Personal Banking portfolio. This is a published credit score designed to measure the risk of default by taking into account various factors from a borrower's financial history. The Bank normally obtains a FICO score at the loan's origination and renewal dates, and updates are obtained on a quarterly basis. Excluded from the table below are certain Personal Banking loans for which FICO scores are not obtained because they generally pertain to commercial customer activities and are often underwritten with other collateral considerations. At September 30, 2017 , these were comprised of $220.7 million in personal real estate loans, or 4.2% of the Personal Banking portfolio, compared to $237.2 million at December 31, 2016 . For the remainder of loans in the Personal Banking portfolio, the table below shows the percentage of balances outstanding at September 30, 2017 and December 31, 2016 by FICO score. Personal Banking Loans % of Loan Category Real Estate - Personal Consumer Revolving Home Equity Consumer Credit Card September 30, 2017 FICO score: Under 600 1.4 % 3.3 % .9 % 5.0 % 600 - 659 2.2 5.7 2.1 15.1 660 - 719 10.1 17.1 9.0 34.9 720 - 779 24.8 26.1 21.2 25.9 780 and over 61.5 47.8 66.8 19.1 Total 100.0 % 100.0 % 100.0 % 100.0 % December 31, 2016 FICO score: Under 600 1.3 % 3.4 % 1.0 % 4.9 % 600 - 659 2.6 6.4 1.8 15.5 660 - 719 10.4 19.7 9.7 34.9 720 - 779 25.4 26.3 21.1 25.1 780 and over 60.3 44.2 66.4 19.6 Total 100.0 % 100.0 % 100.0 % 100.0 % Troubled debt restructurings As mentioned previously, the Company's impaired loans include loans which have been classified as troubled debt restructurings. Total restructured loans amounted to $73.1 million at September 30, 2017 . Restructured loans are those extended to borrowers who are experiencing financial difficulty and who have been granted a concession. Restructured loans are placed on non-accrual status if the Company does not believe it probable that amounts due under the contractual terms will be collected, and those non-accrual loans totaled $7.2 million at September 30, 2017 . Other performing restructured loans totaled $65.9 million at September 30, 2017 . These include certain business, construction and business real estate loans classified as substandard. Upon maturity, the loans renewed at interest rates judged not to be market rates for new debt with similar risk and as a result the loans were classified as troubled debt restructurings. These commercial loans totaled $51.0 million at September 30, 2017 . These restructured loans are performing in accordance with their modified terms, and because the Company believes it probable that all amounts due under the modified terms of the agreements will be collected, interest on these loans is being recognized on an accrual basis. Troubled debt restructurings also include certain credit card loans under various debt management and assistance programs, which totaled $7.0 million at September 30, 2017 . Modifications to credit card loans generally involve removing the available line of credit, placing loans on amortizing status, and lowering the contractual interest rate. The Company has classified additional loans as troubled debt restructurings because they were not reaffirmed by the borrower in bankruptcy proceedings. At September 30, 2017 , these loans totaled $7.7 million in personal real estate, revolving home equity, and consumer loans. Interest on these loans is being recognized on an accrual basis, as the borrowers are continuing to make payments under the terms of the loan agreements. The following table shows the outstanding balances of loans classified as troubled debt restructurings at September 30, 2017 , in addition to the outstanding balances of these restructured loans which the Company considers to have been in default at any time during the past twelve months. For purposes of this disclosure, the Company considers "default" to mean 90 days or more past due as to interest or principal. (In thousands) September 30, 2017 Balance 90 days past due at any time during previous 12 months Commercial: Business $ 40,608 $ — Real estate - construction and land 1,304 — Real estate - business 10,353 623 Personal Banking: Real estate - personal 7,996 397 Consumer 5,235 32 Revolving home equity 578 42 Consumer credit card 7,015 800 Total restructured loans $ 73,089 $ 1,894 For those loans on non-accrual status also classified as restructured, the modification did not create any further financial effect on the Company as those loans were already recorded at net realizable value. For those performing commercial loans classified as restructured, there were no concessions involving forgiveness of principal or interest and, therefore, there was no financial impact to the Company as a result of modification to these loans. No financial impact resulted from those performing loans where the debt was not reaffirmed in bankruptcy, as no changes to loan terms occurred in that process. The effects of modifications to consumer credit card loans were estimated to decrease interest income by approximately $979 thousand on an annual, pre-tax basis, compared to amounts contractually owed. The allowance for loan losses related to troubled debt restructurings on non-accrual status is determined by individual evaluation, including collateral adequacy, using the same process as loans on non-accrual status which are not classified as troubled debt restructurings. Those performing loans classified as troubled debt restructurings are accruing loans which management expects to collect under contractual terms. Performing commercial loans have had no other concessions granted other than being renewed at an interest rate judged not to be market. As such, they have similar risk characteristics as non-troubled debt commercial loans and are collectively evaluated based on internal risk rating, loan type, delinquency, historical experience and current economic factors. Performing personal banking loans classified as troubled debt restructurings resulted from the borrower not reaffirming the debt during bankruptcy and have had no other concession granted, other than the Bank's future limitations on collecting payment deficiencies or in pursuing foreclosure actions. As such, they have similar risk characteristics as non-troubled debt personal banking loans and are evaluated collectively based on loan type, delinquency, historical experience and current economic factors. If a troubled debt restructuring defaults and is already on non-accrual status, the allowance for loan losses continues to be based on individual evaluation, using discounted expected cash flows or the fair value of collateral. If an accruing troubled debt restructuring defaults, the loan's risk rating is downgraded to non-accrual status and the loan's related allowance for loan losses is determined based on individual evaluation, or if necessary, the loan is charged off and collection efforts begun. The Company had commitments of $10.6 million at September 30, 2017 to lend additional funds to borrowers with restructured loans. Loans held for sale The Company designates certain long-term fixed rate personal real estate loans as held for sale, and the Company has elected the fair value option for these loans. The election of the fair value option aligns the accounting for these loans with the related economic hedges discussed in Note 10. The loans are primarily sold to FNMA, FHLMC, and GNMA. At September 30, 2017 , the fair value of these loans was $11.3 million , and the unpaid principal balance was $10.9 million . The Company also designates student loan originations as held for sale. The borrowers are credit-worthy students who are attending colleges and universities. The loans are intended to be sold in the secondary market, and the Company maintains contracts with Sallie Mae to sell the loans within 210 days after the last disbursement to the student. These loans are carried at lower of cost or fair value, which at September 30, 2017 totaled $6.0 million . At September 30, 2017 , none of the loans held for sale were on non-accrual status or 90 days past due and still accruing. Foreclosed real estate/repossessed assets The Company’s holdings of foreclosed real estate totaled $1.1 million and $366 thousand at September 30, 2017 and December 31, 2016 , respectively. Personal property acquired in repossession, generally autos and marine and recreational vehicles, totaled $2.7 million and $2.2 million at September 30, 2017 and December 31, 2016 , respectively. Upon acquisition, these assets are recorded at fair value less estimated selling costs at the date of foreclosure, establishing a new cost basis. They are subsequently carried at the lower of this cost basis or fair value less estimated selling costs.

Investment Securities

Investment Securities	9 Months Ended
	Sep. 30, 2017
Investment Securities [Abstract]
Investment Securities	Investment Securities Investment securities, at fair value, consisted of the following at September 30, 2017 and December 31, 2016 . (In thousands) Sept. 30, 2017 December 31, 2016 Available for sale $ 9,109,287 $ 9,649,203 Trading 24,605 22,225 Non-marketable 99,268 99,558 Total investment securities $ 9,233,160 $ 9,770,986 Most of the Company’s investment securities are classified as available for sale, and this portfolio is discussed in more detail below. The available for sale and the trading portfolios are carried at fair value. Securities which are classified as non-marketable include Federal Home Loan Bank (FHLB) stock and Federal Reserve Bank stock held for debt and regulatory purposes, which totaled $47.3 million at September 30, 2017 and $46.9 million at December 31, 2016 . Investment in Federal Reserve Bank stock is based on the capital structure of the investing bank, and investment in FHLB stock is tied to the level of borrowings from the FHLB. These holdings are carried at cost. Non-marketable securities also include private equity investments, which amounted to $51.7 million at September 30, 2017 and $52.3 million at December 31, 2016 . In the absence of readily ascertainable market values, these securities are carried at estimated fair value. A summary of the available for sale investment securities by maturity groupings as of September 30, 2017 is shown below. The investment portfolio includes agency mortgage-backed securities, which are guaranteed by agencies such as the FHLMC, FNMA, GNMA and FDIC, in addition to non-agency mortgage-backed securities, which have no guarantee but are collateralized by commercial and residential mortgages. Also included are certain other asset-backed securities, which are primarily collateralized by credit cards, automobiles, student loans, and commercial loans. These securities differ from traditional debt securities primarily in that they may have uncertain maturity dates and are priced based on estimated prepayment rates on the underlying collateral. (In thousands) Amortized Cost Fair Value U.S. government and federal agency obligations: Within 1 year $ 57,511 $ 58,238 After 1 but within 5 years 570,284 573,789 After 5 but within 10 years 218,912 219,468 After 10 years 69,517 67,109 Total U.S. government and federal agency obligations 916,224 918,604 Government-sponsored enterprise obligations: Within 1 year 187,032 187,027 After 1 but within 5 years 247,444 247,141 After 10 years 35,927 35,246 Total government-sponsored enterprise obligations 470,403 469,414 State and municipal obligations: Within 1 year 177,616 178,836 After 1 but within 5 years 659,012 671,931 After 5 but within 10 years 800,504 819,943 After 10 years 50,004 49,693 Total state and municipal obligations 1,687,136 1,720,403 Mortgage and asset-backed securities: Agency mortgage-backed securities 2,741,329 2,756,973 Non-agency mortgage-backed securities 1,062,079 1,066,764 Asset-backed securities 1,735,004 1,736,966 Total mortgage and asset-backed securities 5,538,412 5,560,703 Other debt securities: Within 1 year 13,388 13,393 After 1 but within 5 years 207,556 210,022 After 5 but within 10 years 133,140 133,226 Total other debt securities 354,084 356,641 Equity securities 5,353 83,522 Total available for sale investment securities $ 8,971,612 $ 9,109,287 Investments in U.S. government and federal agency obligations include U.S. Treasury inflation-protected securities, which totaled $438.7 million , at fair value, at September 30, 2017 . Interest paid on these securities increases with inflation and decreases with deflation, as measured by the Consumer Price Index. Included in state and municipal obligations are $16.9 million , at fair value, of auction rate securities, which were purchased from bank customers in 2008. Interest on these bonds is currently being paid at the maximum failed auction rates. Included in equity securities is common and preferred stock held by the holding company, Commerce Bancshares, Inc. (the Parent), with a fair value of $83.4 million at September 30, 2017 . For securities classified as available for sale, the following table shows the unrealized gains and losses (pre-tax) in accumulated other comprehensive income, by security type. (In thousands) Amortized Cost Gross Gross Fair Value September 30, 2017 U.S. government and federal agency obligations $ 916,224 $ 6,359 $ (3,979 ) $ 918,604 Government-sponsored enterprise obligations 470,403 844 (1,833 ) 469,414 State and municipal obligations 1,687,136 34,952 (1,685 ) 1,720,403 Mortgage and asset-backed securities: Agency mortgage-backed securities 2,741,329 28,827 (13,183 ) 2,756,973 Non-agency mortgage-backed securities 1,062,079 8,536 (3,851 ) 1,066,764 Asset-backed securities 1,735,004 5,047 (3,085 ) 1,736,966 Total mortgage and asset-backed securities 5,538,412 42,410 (20,119 ) 5,560,703 Other debt securities 354,084 3,293 (736 ) 356,641 Equity securities 5,353 78,169 — 83,522 Total $ 8,971,612 $ 166,027 $ (28,352 ) $ 9,109,287 December 31, 2016 U.S. government and federal agency obligations $ 919,904 $ 7,312 $ (6,312 ) $ 920,904 Government-sponsored enterprise obligations 450,448 1,126 (1,576 ) 449,998 State and municipal obligations 1,778,684 12,223 (12,693 ) 1,778,214 Mortgage and asset-backed securities: Agency mortgage-backed securities 2,674,964 31,610 (20,643 ) 2,685,931 Non-agency mortgage-backed securities 1,054,446 7,686 (6,493 ) 1,055,639 Asset-backed securities 2,389,176 3,338 (11,213 ) 2,381,301 Total mortgage and asset-backed securities 6,118,586 42,634 (38,349 ) 6,122,871 Other debt securities 327,030 935 (2,012 ) 325,953 Equity securities 5,678 45,585 — 51,263 Total $ 9,600,330 $ 109,815 $ (60,942 ) $ 9,649,203 The Company’s impairment policy requires a review of all securities for which fair value is less than amortized cost. Special emphasis and analysis is placed on securities whose credit rating has fallen below A3 (Moody's) or A- (Standard & Poor's), whose fair values have fallen more than 20% below purchase price for an extended period of time, or have been identified based on management’s judgment. These securities are placed on a watch list, and for all such securities, cash flow analyses are prepared. For more complex analyses, detailed cash flow models are prepared which use inputs specific to each security. Inputs to these models include factors such as cash flow received, contractual payments required, and various other information related to the underlying collateral (including current delinquencies), collateral loss severity rates (including loan to values), expected delinquency rates, credit support from other tranches, and prepayment speeds. Stress tests are performed at varying levels of delinquency rates, prepayment speeds and loss severities in order to gauge probable ranges of credit loss. At September 30, 2017 , the fair value of securities on this watch list was $63.6 million compared to $79.6 million at December 31, 2016 . As of September 30, 2017 , the Company had recorded other-than-temporary impairment (OTTI) on certain non-agency mortgage-backed securities, part of the watch list mentioned above, which had an aggregate fair value of $28.1 million . The cumulative credit-related portion of the impairment on these securities, which was recorded in earnings, totaled $14.2 million . The Company does not intend to sell these securities and believes it is not likely that it will be required to sell the securities before the recovery of their amortized cost. The credit-related portion of the loss on these securities was based on the cash flows projected to be received over the estimated life of the securities, discounted to present value, and compared to the current amortized cost bases of the securities. Significant inputs to the cash flow models used to calculate the credit losses on these securities at September 30, 2017 included the following: Significant Inputs Range Prepayment CPR 3% - 25% Projected cumulative default 13% - 50% Credit support 0% - 47% Loss severity 16% - 63% The following table presents a rollforward of the cumulative OTTI credit losses recognized in earnings on all available for sale debt securities. For the Nine Months Ended September 30 (In thousands) 2017 2016 Cumulative OTTI credit losses at January 1 $ 14,080 $ 14,129 Credit losses on debt securities for which impairment was not previously recognized 98 — Credit losses on debt securities for which impairment was previously recognized 274 270 Increase in expected cash flows that are recognized over remaining life of security (207 ) (171 ) Cumulative OTTI credit losses at September 30 $ 14,245 $ 14,228 Securities with unrealized losses recorded in accumulated other comprehensive income are shown in the table below, along with the length of the impairment period. Less than 12 months 12 months or longer Total (In thousands) Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses September 30, 2017 U.S. government and federal agency obligations $ 123,071 $ 3,979 $ — $ — $ 123,071 $ 3,979 Government-sponsored enterprise obligations 190,141 1,650 49,793 183 239,934 1,833 State and municipal obligations 95,890 692 38,026 993 133,916 1,685 Mortgage and asset-backed securities: Agency mortgage-backed securities 887,047 9,741 223,550 3,442 1,110,597 13,183 Non-agency mortgage-backed securities 381,896 1,674 156,455 2,177 538,351 3,851 Asset-backed securities 488,409 522 279,402 2,563 767,811 3,085 Total mortgage and asset-backed securities 1,757,352 11,937 659,407 8,182 2,416,759 20,119 Other debt securities 70,143 622 9,363 114 79,506 736 Total $ 2,236,597 $ 18,880 $ 756,589 $ 9,472 $ 2,993,186 $ 28,352 December 31, 2016 U.S. government and federal agency obligations $ 349,538 $ 2,823 $ 32,208 $ 3,489 $ 381,746 $ 6,312 Government-sponsored enterprise obligations 190,441 1,576 — — 190,441 1,576 State and municipal obligations 700,779 12,164 15,195 529 715,974 12,693 Mortgage and asset-backed securities: Agency mortgage-backed securities 1,147,416 20,638 2,150 5 1,149,566 20,643 Non-agency mortgage-backed securities 688,131 6,373 34,946 120 723,077 6,493 Asset-backed securities 780,209 5,277 358,778 5,936 1,138,987 11,213 Total mortgage and asset-backed securities 2,615,756 32,288 395,874 6,061 3,011,630 38,349 Other debt securities 179,639 1,986 975 26 180,614 2,012 Total $ 4,036,153 $ 50,837 $ 444,252 $ 10,105 $ 4,480,405 $ 60,942 The Company’s holdings of state and municipal obligations included gross unrealized losses of $1.7 million at September 30, 2017 , of which $221 thousand related to auction rate securities. This portfolio totaled $1.7 billion at fair value, or 18.9% of total available for sale securities. The average credit quality of the portfolio is Aa2 as rated by Moody’s. The portfolio is diversified in order to reduce risk, and the Company has processes and procedures in place to monitor its holdings, identify signs of financial distress and, if necessary, exit its positions in a timely manner. The following tables present proceeds from sales of securities and the components of investment securities gains and losses which have been recognized in earnings. For the Nine Months Ended September 30 (In thousands) 2017 2016 Proceeds from sales of securities: Available for sale $ 367,453 $ — Non-marketable 1,583 7,946 Total proceeds $ 369,036 $ 7,946 Investment securities gains (losses), net: Available for sale: Losses realized on called bonds $ (254 ) $ — Gains realized on sales 592 — Losses realized on sales (568 ) — Gains realized on donations of securities 6,707 — Other-than-temporary impairment recognized on debt securities (372 ) (270 ) Non-marketable: Gains realized on sales 645 3,717 Losses realized on sales (880 ) (502 ) Fair value adjustments, net (8,028 ) (6,649 ) Total gains (losses), net $ (2,158 ) $ (3,704 ) At September 30, 2017 , securities totaling $3.7 billion in fair value were pledged to secure public fund deposits, securities sold under agreements to repurchase, trust funds, and borrowings at the Federal Reserve Bank and FHLB. Securities pledged under agreements pursuant to which the collateral may be sold or re-pledged by the secured parties approximated $667.2 million , while the remaining securities were pledged under agreements pursuant to which the secured parties may not sell or re-pledge the collateral. Except for obligations of various government-sponsored enterprises such as FNMA, FHLB and FHLMC, no investment in a single issuer exceeded 10% of stockholders’ equity.

Goodwill And Other Intangible A

Goodwill And Other Intangible Assets	9 Months Ended
	Sep. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill And Other Intangible Assets	Goodwill and Other Intangible Assets The following table presents information about the Company's intangible assets which have estimable useful lives. September 30, 2017 December 31, 2016 (In thousands) Gross Carrying Amount Accumulated Amortization Valuation Allowance Net Amount Gross Carrying Amount Accumulated Amortization Valuation Allowance Net Amount Amortizable intangible assets: Core deposit premium $ 31,270 $ (28,127 ) $ — $ 3,143 $ 31,270 $ (27,429 ) $ — $ 3,841 Mortgage servicing rights 7,361 (3,100 ) (16 ) 4,245 5,672 (2,782 ) (22 ) 2,868 Total $ 38,631 $ (31,227 ) $ (16 ) $ 7,388 $ 36,942 $ (30,211 ) $ (22 ) $ 6,709 Aggregate amortization expense on intangible assets was $338 thousand and $374 thousand for the three month periods ended September 30, 2017 and 2016 , respectively, and $1.0 million and $1.2 million for the nine month periods ended September 30, 2017 and 2016 , respectively. The following table shows the estimated annual amortization expense for the next five fiscal years. This expense is based on existing asset balances and the interest rate environment as of September 30, 2017 . The Company’s actual amortization expense in any given period may be different from the estimated amounts depending upon the acquisition of intangible assets, changes in mortgage interest rates, prepayment rates and other market conditions. (In thousands) 2017 $ 1,331 2018 1,181 2019 996 2020 834 2021 711 Changes in the carrying amount of goodwill and net other intangible assets for the nine month period ended September 30, 2017 is as follows: (In thousands) Goodwill Core Deposit Premium Mortgage Servicing Rights Balance January 1, 2017 $ 138,921 $ 3,841 $ 2,868 Originations — — 1,689 Amortization — (698 ) (318 ) Impairment reversal — — 6 Balance September 30, 2017 $ 138,921 $ 3,143 $ 4,245 Goodwill allocated to the Company’s operating segments at September 30, 2017 and December 31, 2016 is shown below. (In thousands) Consumer segment $ 70,721 Commercial segment 67,454 Wealth segment 746 Total goodwill $ 138,921

Guarantees

Guarantees	9 Months Ended
	Sep. 30, 2017
Guarantees [Abstract]
Guarantees	Guarantees The Company, as a provider of financial services, routinely issues financial guarantees in the form of financial and performance standby letters of credit. Standby letters of credit are contingent commitments issued by the Company generally to guarantee the payment or performance obligation of a customer to a third party. While these represent a potential outlay by the Company, a significant amount of the commitments may expire without being drawn upon. The Company has recourse against the customer for any amount it is required to pay to a third party under a standby letter of credit. The letters of credit are subject to the same credit policies, underwriting standards and approval process as loans made by the Company. Most of the standby letters of credit are secured, and in the event of nonperformance by customers, the Company has rights to the underlying collateral, which could include commercial real estate, physical plant and property, inventory, receivables, cash and marketable securities. Upon issuance of standby letters of credit, the Company recognizes a liability for the fair value of the obligation undertaken, which is estimated to be equivalent to the amount of fees received from the customer over the life of the agreement. At September 30, 2017 , that net liability was $2.1 million , which will be accreted into income over the remaining life of the respective commitments. The contractual amount of these letters of credit, which represents the maximum potential future payments guaranteed by the Company, was $338.4 million at September 30, 2017 . The Company periodically enters into credit risk participation agreements (RPAs) as a guarantor to other financial institutions, in order to mitigate those institutions’ credit risk associated with interest rate swaps with third parties. The RPA stipulates that, in the event of default by the third party on the interest rate swap, the Company will reimburse a portion of the loss borne by the financial institution. These interest rate swaps are normally collateralized (generally with real property, inventories and equipment) by the third party, which limits the credit risk associated with the Company’s RPAs. The third parties usually have other borrowing relationships with the Company. The Company monitors overall borrower collateral and at September 30, 2017 , believes sufficient collateral is available to cover potential swap losses. The RPAs are carried at fair value throughout their term with all changes in fair value, including those due to a change in the third party’s creditworthiness, recorded in current earnings. The terms of the RPAs, which correspond to the terms of the underlying swaps, range from 3 to 11 years. At September 30, 2017 , the fair value of the Company's guarantee liabilities for RPAs was $129 thousand , and the notional amount of the underlying swaps was $74.9 million . The maximum potential future payment guaranteed by the Company cannot be readily estimated but is dependent upon the fair value of the interest rate swaps at the time of default.

Pension

Pension	9 Months Ended
	Sep. 30, 2017
Pension [Abstract]
Pension	Pension The amount of net pension cost is shown in the table below: For the Three Months Ended September 30 For the Nine Months Ended September 30 (In thousands) 2017 2016 2017 2016 Service cost - benefits earned during the period $ 193 $ 135 $ 450 $ 406 Interest cost on projected benefit obligation 923 986 2,869 2,958 Expected return on plan assets (1,463 ) (1,437 ) (4,339 ) (4,313 ) Amortization of prior service cost (67 ) (68 ) (203 ) (203 ) Amortization of unrecognized net loss 630 647 1,864 1,940 Net periodic pension cost $ 216 $ 263 $ 641 $ 788 Substantially all benefits accrued under the Company’s defined benefit pension plan were frozen effective January 1, 2005, and the remaining benefits were frozen effective January 1, 2011. During the first nine months of 2017 , the Company made a discretionary contribution of $5.5 million to its defined benefit pension plan in order to reduce pension guarantee costs. The Company also made minimal funding contributions to a supplemental executive retirement plan (the CERP), which carries no segregated assets. The Company has no plans to make any further contributions, other than those related to the CERP, during the remainder of 2017 .

Common Stock

Common Stock	9 Months Ended
	Sep. 30, 2017
Common Stock [Abstract]
Common Stock	Common Stock * Presented below is a summary of the components used to calculate basic and diluted income per share. The Company applies the two-class method of computing income per share, as nonvested share-based awards that contain nonforfeitable rights to dividends are considered securities which participate in undistributed earnings with common stock. The two-class method requires the calculation of separate income per share amounts for the nonvested share-based awards and for common stock. Income per share attributable to common stock is shown in the table below. Nonvested share-based awards are further discussed in Note 12. For the Three Months Ended September 30 For the Nine Months Ended September 30 (In thousands, except per share data) 2017 2016 2017 2016 Basic income per common share: Net income attributable to Commerce Bancshares, Inc. $ 74,564 $ 68,545 $ 225,028 $ 203,812 Less preferred stock dividends 2,250 2,250 6,750 6,750 Net income available to common shareholders $ 72,314 $ 66,295 218,278 197,062 Less income allocated to nonvested restricted stock 862 913 2,750 2,747 Net income allocated to common stock $ 71,452 $ 65,382 $ 215,528 $ 194,315 Weighted average common shares outstanding 100,598 100,198 100,509 100,231 Basic income per common share $ .71 $ .65 $ 2.14 $ 1.94 Diluted income per common share: Net income available to common shareholders $ 72,314 $ 66,295 $ 218,278 $ 197,062 Less income allocated to nonvested restricted stock 860 912 2,743 2,743 Net income allocated to common stock $ 71,454 $ 65,383 $ 215,535 $ 194,319 Weighted average common shares outstanding 100,598 100,198 100,509 100,231 Net effect of the assumed exercise of stock-based awards - based on the treasury stock method using the average market price for the respective periods 336 255 358 248 Weighted average diluted common shares outstanding 100,934 100,453 100,867 100,479 Diluted income per common share $ .71 $ .65 $ 2.14 $ 1.93 Unexercised stock appreciation rights of 139 thousand and 89 thousand were excluded in the computation of diluted income per common share for the nine month periods ended September 30, 2017 and 2016 , respectively, because their inclusion would have been anti-dilutive. * All prior year share and per share amounts in this note have been restated for the 5% common stock dividend distributed in December 2016.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	9 Months Ended
	Sep. 30, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income	Accumulated Other Comprehensive Income The table below shows the activity and accumulated balances for components of other comprehensive income. The largest component is the unrealized holding gains and losses on available for sale securities. Unrealized gains and losses on debt securities for which an other-than-temporary impairment (OTTI) has been recorded in current earnings are shown separately below. The other component is the amortization from other comprehensive income of losses associated with pension benefits, which occurs as the losses are included in current net periodic pension cost. Unrealized Gains (Losses) on Securities (1) Pension Loss (2) Total Accumulated Other Comprehensive Income (In thousands) OTTI Other Balance January 1, 2017 $ 2,975 $ 27,328 $ (19,328 ) $ 10,975 Other comprehensive income before reclassifications 365 94,794 — 95,159 Amounts reclassified from accumulated other comprehensive income 372 (6,731 ) 1,661 (4,698 ) Current period other comprehensive income, before tax 737 88,063 1,661 90,461 Income tax expense (280 ) (33,464 ) (631 ) (34,375 ) Current period other comprehensive income, net of tax 457 54,599 1,030 56,086 Transfer of unrealized gain on securities for which impairment was not previously recognized 24 (24 ) — — Balance September 30, 2017 $ 3,456 $ 81,903 $ (18,298 ) $ 67,061 Balance January 1, 2016 $ 3,316 $ 49,750 $ (20,596 ) $ 32,470 Other comprehensive income (loss) before reclassifications (837 ) 141,752 — 140,915 Amounts reclassified from accumulated other comprehensive income 270 — 1,737 2,007 Current period other comprehensive income (loss), before tax (567 ) 141,752 1,737 142,922 Income tax (expense) benefit 215 (53,865 ) (660 ) (54,310 ) Current period other comprehensive income (loss), net of tax (352 ) 87,887 1,077 88,612 Balance September 30, 2016 $ 2,964 $ 137,637 $ (19,519 ) $ 121,082 (1) The pre-tax amounts reclassified from accumulated other comprehensive income are included in "investment securities gains (losses), net" in the consolidated statements of income. (2) The pre-tax amounts reclassified from accumulated other comprehensive income are included in the computation of net periodic pension cost as "amortization of prior service cost" and "amortization of unrecognized net loss" (see Note 6), for inclusion in the consolidated statements of income.

Segments

Segments	9 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Segments	Segments The Company segregates financial information for use in assessing its performance and allocating resources among three operating segments: Consumer, Commercial and Wealth. The Consumer segment consists of various consumer loan and deposit products offered through its retail branch network of approximately 180 locations. This segment also includes indirect and other consumer loan financing businesses, along with debit and credit card loan and fee businesses. Residential mortgage origination, sales and servicing functions are included in this consumer segment, but residential mortgage loans retained by the Company are not considered part of this segment. The Commercial segment provides corporate lending, leasing, and international services, along with business and governmental deposit products and commercial cash management services. This segment includes both merchant and commercial bank card products. It also includes the Capital Markets Group which sells fixed income securities and provides safekeeping and accounting services to its business and correspondent bank customers. The Wealth segment provides traditional trust and estate planning, advisory and discretionary investment management, and brokerage services. This segment also provides various loan and deposit related services to its private banking customers. The following table presents selected financial information by segment and reconciliations of combined segment totals to consolidated totals. There were no material intersegment revenues among the three segments. Management periodically makes changes to methods of assigning costs and income to its business segments to better reflect operating results. If appropriate, these changes are reflected in prior year information presented below. (In thousands) Consumer Commercial Wealth Segment Totals Other/Elimination Consolidated Totals Three Months Ended September 30, 2017 Net interest income $ 70,793 $ 82,012 $ 11,744 $ 164,549 $ 18,042 $ 182,591 Provision for loan losses (11,067 ) 335 (10 ) (10,742 ) 38 (10,704 ) Non-interest income 35,194 47,902 40,404 123,500 (1,258 ) 122,242 Investment securities losses, net — — — — (3,037 ) (3,037 ) Non-interest expense (72,607 ) (71,468 ) (30,528 ) (174,603 ) (9,969 ) (184,572 ) Income before income taxes $ 22,313 $ 58,781 $ 21,610 $ 102,704 $ 3,816 $ 106,520 Nine Months Ended September 30, 2017 Net interest income $ 207,421 $ 243,517 $ 35,515 $ 486,453 $ 57,218 $ 543,671 Provision for loan losses (31,531 ) 959 (9 ) (30,581 ) (2,009 ) (32,590 ) Non-interest income 101,211 144,781 116,961 362,953 (561 ) 362,392 Investment securities losses, net — — — — (2,158 ) (2,158 ) Non-interest expense (217,733 ) (219,307 ) (90,323 ) (527,363 ) (28,633 ) (555,996 ) Income before income taxes $ 59,368 $ 169,950 $ 62,144 $ 291,462 $ 23,857 $ 315,319 Three Months Ended September 30, 2016 Net interest income $ 67,375 $ 78,514 $ 10,782 $ 156,671 $ 14,572 $ 171,243 Provision for loan losses (9,033 ) 2,432 (5 ) (6,606 ) (657 ) (7,263 ) Non-interest income 34,230 49,832 36,676 120,738 (1,419 ) 119,319 Investment securities losses, net — — — — (1,965 ) (1,965 ) Non-interest expense (70,134 ) (71,200 ) (28,172 ) (169,506 ) (11,736 ) (181,242 ) Income before income taxes $ 22,438 $ 59,578 $ 19,281 $ 101,297 $ (1,205 ) $ 100,092 Nine Months Ended September 30, 2016 Net interest income $ 201,166 $ 231,780 $ 32,604 $ 465,550 $ 41,297 $ 506,847 Provision for loan losses (26,533 ) 3,919 (120 ) (22,734 ) (3,184 ) (25,918 ) Non-interest income 97,165 149,240 107,696 354,101 812 354,913 Investment securities losses, net — — — — (3,704 ) (3,704 ) Non-interest expense (209,660 ) (211,450 ) (85,116 ) (506,226 ) (29,578 ) (535,804 ) Income before income taxes $ 62,138 $ 173,489 $ 55,064 $ 290,691 $ 5,643 $ 296,334 The information presented above was derived from the internal profitability reporting system used by management to monitor and manage the financial performance of the Company. This information is based on internal management accounting procedures and methods, which have been developed to reflect the underlying economics of the businesses. The methodologies are applied in connection with funds transfer pricing and assignment of overhead costs among segments. Funds transfer pricing was used in the determination of net interest income by assigning a standard cost (credit) for funds used (provided) by assets and liabilities based on their maturity, prepayment and/or repricing characteristics. The segment activity, as shown above, includes both direct and allocated items. Amounts in the “Other/Elimination” column include activity not related to the segments, such as that relating to administrative functions, the investment securities portfolio, and the effect of certain expense allocations to the segments. The provision for loan losses in this category contains the difference between net loan charge-offs assigned directly to the segments and the recorded provision for loan loss expense. Included in this category’s net interest income are earnings of the investment portfolio, which are not allocated to a segment. The performance measurement of the operating segments is based on the management structure of the Company and is not necessarily comparable with similar information for any other financial institution. The information is also not necessarily indicative of the segments' financial condition and results of operations if they were independent entities.

Derivative Instruments

Derivative Instruments	9 Months Ended
	Sep. 30, 2017
Derivative Instrument Detail [Abstract]
Derivative Instruments	Derivative Instruments The notional amounts of the Company’s derivative instruments are shown in the table below. These contractual amounts, along with other terms of the derivative, are used to determine amounts to be exchanged between counterparties and are not a measure of loss exposure. The Company’s derivative instruments are accounted for as free-standing derivatives, and changes in their fair value are recorded in current earnings. (In thousands) September 30, 2017 December 31, 2016 Interest rate swaps $ 1,723,448 $ 1,685,099 Interest rate caps 31,923 59,379 Credit risk participation agreements 112,348 121,514 Foreign exchange contracts 8,783 4,046 Mortgage loan commitments 23,616 12,429 Mortgage loan forward sale contracts 1,607 6,626 Forward TBA contracts 32,000 15,000 Total notional amount $ 1,933,725 $ 1,904,093 The largest group of notional amounts relate to interest rate swap contracts sold to commercial customers who wish to modify their interest rate sensitivity. These swaps are offset by matching contracts purchased by the Company from other financial dealer institutions. Contracts with dealers that require central clearing are novated to a regulated clearing organization who becomes the Company's legal counterparty. Because of the matching terms of the offsetting contracts, in addition to collateral provisions which mitigate the impact of non-performance risk, changes in fair value subsequent to initial recognition have a minimal effect on earnings. Many of the Company’s interest rate swap contracts with large financial institutions contain contingent features relating to debt ratings or capitalization levels. Under these provisions, if the Company’s debt rating falls below investment grade or if the Company ceases to be “well-capitalized” under risk-based capital guidelines, certain counterparties can require immediate and ongoing collateralization on interest rate swaps in net liability positions or instant settlement of the contracts. The Company maintains debt ratings and capital well above these minimum requirements. The Company also contracts with other financial institutions, as a guarantor or beneficiary, to share credit risk associated with certain interest rate swaps through risk participation agreements. The Company’s risks and responsibilities as guarantor are further discussed in Note 5 on Guarantees. In addition, the Company enters into foreign exchange contracts, which are mainly comprised of contracts to purchase or deliver foreign currencies for customers at specific future dates. Under its program to sell residential mortgage loans in the secondary market, the Company designates certain newly-originated residential mortgage loans as held for sale. Derivative instruments arising from this activity include mortgage loan commitments and forward loan sale commitments. Changes in the fair values of the loan commitments and funded loans prior to sale that are due to changes in interest rates are economically hedged with forward contracts to sell residential mortgage-backed securities in the to-be-announced (TBA) market. These forward TBA contracts are also considered to be derivatives and are settled in cash at the security settlement date. The fair values of the Company's derivative instruments, whose notional amounts are listed above, are shown in the table below. Derivative instruments with a positive fair value (asset derivatives) are reported in other assets in the consolidated balance sheets, while derivative instruments with a negative fair value (liability derivatives) are reported in other liabilities in the consolidated balance sheets. Information about the valuation methods used to determine fair value is provided in Note 13 on Fair Value Measurements. Asset Derivatives Liability Derivatives Sept. 30, 2017 Dec. 31, 2016 Sept. 30, 2017 Dec. 31, 2016 (In thousands ) Fair Value Fair Value Derivative instruments: Interest rate swaps $ 10,630 $ 12,987 $ (5,775 ) $ (12,987 ) Interest rate caps 29 78 (29 ) (78 ) Credit risk participation agreements 56 65 (129 ) (156 ) Foreign exchange contracts 68 66 (30 ) (4 ) Mortgage loan commitments 757 355 — (6 ) Mortgage loan forward sale contracts 8 — — (63 ) Forward TBA contracts 102 15 (16 ) (45 ) Total $ 11,650 $ 13,566 $ (5,979 ) $ (13,339 ) Due to rule changes by the Company's clearing counterparty effective January 2017, collateral previously recorded in "other assets" has been reclassified and offset against the fair values of cleared swaps, such that at September 30, 2017 , the positive fair values of cleared swaps were reduced by $2.4 million and the negative fair values of cleared swaps were reduced by $7.3 million , as reflected in the table above. The effects of derivative instruments on the consolidated statements of income are shown in the table below. Location of Gain or (Loss) Recognized in Income on Derivatives Amount of Gain or (Loss) Recognized in Income on Derivatives For the Three Months Ended September 30 For the Nine Months Ended September 30 (In thousands) 2017 2016 2017 2016 Derivative instruments: Interest rate swaps Other non-interest income $ 702 $ 203 $ 1,301 $ 3,198 Credit risk participation agreements Other non-interest income 7 50 18 (8 ) Foreign exchange contracts Other non-interest income 51 (20 ) (24 ) (12 ) Mortgage loan commitments Loan fees and sales (114 ) 86 408 613 Mortgage loan forward sale contracts Loan fees and sales 8 1 70 1 Forward TBA contracts Loan fees and sales (322 ) (172 ) (580 ) (898 ) Total $ 332 $ 148 $ 1,193 $ 2,894 The following table shows the extent to which assets and liabilities relating to derivative instruments have been offset in the consolidated balance sheets. It also provides information about these instruments which are subject to an enforceable master netting arrangement, irrespective of whether they are offset, and the extent to which the instruments could potentially be offset. Also shown is collateral received or pledged in the form of other financial instruments, which is generally cash or marketable securities. The collateral amounts in this table are limited to the outstanding balances of the related asset or liability (after netting is applied); thus amounts of excess collateral are not shown. Most of the derivatives in the following table were transacted under master netting arrangements that contain a conditional right of offset, such as close-out netting, upon default. The Company is party to master netting arrangements with most of its swap derivative counterparties; however, the Company does not offset derivative assets and liabilities under these arrangements on its consolidated balance sheet. Collateral, usually in the form of marketable securities, is exchanged between the Company and dealer bank counterparties and is generally subject to thresholds and transfer minimums. By contract, it may be sold or re-pledged by the secured party until recalled at a subsequent valuation date by the pledging party. For those swap transactions requiring central clearing, the Company posts cash and securities to its clearing agent. Collateral positions are valued daily, and adjustments to amounts received and pledged by the Company are made as appropriate to maintain proper collateralization for these transactions. Swap derivative transactions with customers are generally secured by rights to non-financial collateral, such as real and personal property, which is not shown in the table below. Gross Amounts Not Offset in the Balance Sheet (In thousands) Gross Amount Recognized Gross Amounts Offset in the Balance Sheet Net Amounts Presented in the Balance Sheet Financial Instruments Available for Offset Collateral Received/Pledged Net Amount September 30, 2017 Assets: Derivatives subject to master netting agreements $ 10,809 $ — $ 10,809 $ (364 ) $ — $ 10,445 Derivatives not subject to master netting agreements 841 — 841 Total derivatives 11,650 — 11,650 Liabilities: Derivatives subject to master netting agreements $ 5,829 $ — $ 5,829 $ (364 ) $ (1,692 ) $ 3,773 Derivatives not subject to master netting agreements 150 — 150 Total derivatives 5,979 — 5,979 December 31, 2016 Assets: Derivatives subject to master netting agreements $ 13,111 $ — $ 13,111 $ (3,391 ) $ — $ 9,720 Derivatives not subject to master netting agreements 455 — 455 Total derivatives 13,566 — 13,566 Liabilities: Derivatives subject to master netting agreements $ 13,124 $ — $ 13,124 $ (3,391 ) $ (5,292 ) $ 4,441 Derivatives not subject to master netting agreements 215 — 215 Total derivatives 13,339 — 13,339

Resale and Repurchase Agreement

Resale and Repurchase Agreements (Notes)	9 Months Ended
	Sep. 30, 2017
Resale and Repurchase Agreements [Abstract]
Resale and Repurchase Agreements [Text Block]	Resale and Repurchase Agreements The following table shows the extent to which assets and liabilities relating to securities purchased under agreements to resell (resale agreements) and securities sold under agreements to repurchase (repurchase agreements) have been offset in the consolidated balance sheets, in addition to the extent to which they could potentially be offset. Also shown is collateral received or pledged, which consists of marketable securities. The collateral amounts in the table are limited to the outstanding balances of the related asset or liability (after netting is applied); thus amounts of excess collateral are not shown. The agreements in the following table were transacted under master netting arrangements that contain a conditional right of offset, such as close-out netting, upon default. Resale and repurchase agreements are agreements to purchase/sell securities subject to an obligation to resell/repurchase the same or similar securities. They are accounted for as collateralized financing transactions, not as sales and purchases of the securities portfolio. The securities collateral accepted or pledged in resale and repurchase agreements with other financial institutions also may be sold or re-pledged by the secured party, but is usually delivered to and held by third party trustees. The Company generally retains custody of securities pledged for repurchase agreements with customers. The Company is party to several agreements commonly known as collateral swaps. These agreements involve the exchange of collateral under simultaneous repurchase and resale agreements with the same financial institution counterparty. These repurchase and resale agreements have the same principal amounts, inception dates, and maturity dates and have been offset against each other in the consolidated balance sheets, as permitted under the netting provisions of ASC 210-20-45. The collateral swaps totaled $650.0 million at September 30, 2017 and $550.0 million at December 31, 2016 . At September 30, 2017 , the Company had posted collateral of $665.5 million in marketable securities, consisting of agency mortgage-backed bonds and treasuries, and had accepted $663.1 million in investment grade asset-backed, commercial mortgage-backed, and corporate bonds. Gross Amounts Not Offset in the Balance Sheet (In thousands) Gross Amount Recognized Gross Amounts Offset in the Balance Sheet Net Amounts Presented in the Balance Sheet Financial Instruments Available for Offset Securities Collateral Received/Pledged Net Amount September 30, 2017 Total resale agreements, subject to master netting arrangements $ 1,350,000 $ (650,000 ) $ 700,000 $ — $ (700,000 ) $ — Total repurchase agreements, subject to master netting arrangements 1,708,074 (650,000 ) 1,058,074 — (1,058,074 ) — December 31, 2016 Total resale agreements, subject to master netting arrangements $ 1,275,000 $ (550,000 ) $ 725,000 $ — $ (725,000 ) $ — Total repurchase agreements, subject to master netting arrangements 2,221,065 (550,000 ) 1,671,065 — (1,671,065 ) — The table below shows the remaining contractual maturities of repurchase agreements outstanding at September 30, 2017 and December 31, 2016 , in addition to the various types of marketable securities that have been pledged as collateral for these borrowings. Remaining Contractual Maturity of the Agreements (In thousands) Overnight and continuous Up to 90 days Greater than 90 days Total September 30, 2017 Repurchase agreements, secured by: U.S. government and federal agency obligations $ 326,080 $ — $ 450,000 $ 776,080 Government-sponsored enterprise obligations 186,896 — — 186,896 Agency mortgage-backed securities 317,780 19,730 200,000 537,510 Asset-backed securities 117,588 90,000 — 207,588 Total repurchase agreements, gross amount recognized $ 948,344 $ 109,730 $ 650,000 $ 1,708,074 December 31, 2016 Repurchase agreements, secured by: U.S. government and federal agency obligations $ 294,600 $ — $ 300,000 $ 594,600 Government-sponsored enterprise obligations 147,694 — 3,237 150,931 Agency mortgage-backed securities 693,851 24,380 252,473 970,704 Asset-backed securities 474,830 30,000 — 504,830 Total repurchase agreements, gross amount recognized $ 1,610,975 $ 54,380 $ 555,710 $ 2,221,065

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2017
Share-based Compensation [Abstract]
Stock-Based Compensation	Stock-Based Compensation The Company issues stock-based compensation in the form of nonvested restricted stock and stock appreciation rights (SARs). Most of the awards are issued during the first quarter of each year. The stock-based compensation expense that has been charged against income was $3.0 million and $2.6 million in the three months ended September 30, 2017 and 2016 , respectively, and $9.1 million and $8.9 million in the nine months ended September 30, 2017 and 2016 , respectively. The Company adopted ASU 2016-09, "Improvements to Employee Share-Based Payment Accounting," on January 1, 2017. The Company elected to change its method of accounting for forfeitures, as allowed by this guidance. In 2016 and prior years, accruals of compensation cost were reduced by an estimate of awards not expected to vest and further adjusted when actual forfeitures occurred. In 2017 and subsequent years, forfeitures will be accounted for when they occur and recognized in compensation cost at that time. The effect of this change, which was recognized as a cumulative-effect adjustment on January 1, 2017, increased equity and increased deferred tax assets by approximately $1.3 million . ASU 2016-09 also changed the classification of excess tax benefits and deficiencies arising from stock-based payment transactions, resulting in reductions in income tax expense of $4.5 million in the first quarter of 2017, $1.6 million in the second quarter of 2017 and $619 thousand in the third quarter of 2017. Nonvested stock awards generally vest in 4 to 7 years and contain restrictions as to transferability, sale, pledging, or assigning, among others, prior to the end of the vesting period. Dividend and voting rights are conferred upon grant. A summary of the status of the Company’s nonvested share awards as of September 30, 2017 , and changes during the nine month period then ended, is presented below. Shares Weighted Average Grant Date Fair Value Nonvested at January 1, 2017 1,392,451 $34.67 Granted 242,244 57.31 Vested (403,586 ) 30.87 Forfeited (20,250 ) 40.72 Nonvested at September 30, 2017 1,210,859 $40.36 SARs are granted with exercise prices equal to the market price of the Company’s stock at the date of grant. SARs vest ratably over 4 years of continuous service and have 10 -year contractual terms. All SARs must be settled in stock under provisions of the plan. In determining compensation cost, the Black-Scholes option-pricing model is used to estimate the fair value of SARs on date of grant. The current year per share average fair value and the model assumptions are shown in the table below. Weighted per share average fair value at grant date $12.54 Assumptions: Dividend yield 1.6 % Volatility 21.1 % Risk-free interest rate 2.4 % Expected term 7.0 years A summary of SAR activity during the first nine months of 2017 is presented below. (Dollars in thousands, except per share data) Rights Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value Outstanding at January 1, 2017 1,324,954 $34.53 Granted 165,592 57.53 Forfeited (9,448 ) 44.25 Expired (837 ) 36.48 Exercised (317,621 ) 30.86 Outstanding at September 30, 2017 1,162,640 $38.73 6.3 years $ 21,821

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2017
Fair Value Measurements [Abstract]
Fair Value Measurements	Fair Value Measurements The Company uses fair value measurements to record fair value adjustments to certain financial and nonfinancial assets and liabilities and to determine fair value disclosures. Various financial instruments such as available for sale and trading securities, certain non-marketable securities relating to private equity activities, and derivatives are recorded at fair value on a recurring basis. Additionally, from time to time, the Company may be required to record at fair value other assets and liabilities on a nonrecurring basis, such as mortgage servicing rights and certain other investment securities. These nonrecurring fair value adjustments typically involve lower of cost or fair value accounting or write-downs of individual assets. Fair value is 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. Depending on the nature of the asset or liability, the Company uses various valuation techniques and assumptions when estimating fair value. For accounting disclosure purposes, a three-level valuation hierarchy of fair value measurements has been established. The valuation hierarchy is based upon the transparency of inputs to the valuation of an asset or liability as of the measurement date. The three levels are defined as follows: • Level 1 – inputs to the valuation methodology are quoted prices for identical assets or liabilities in active markets. • Level 2 – inputs to the valuation methodology include quoted prices for similar assets and liabilities in active markets, quoted prices for identical or similar assets and liabilities in markets that are not active, and inputs that are observable for the assets or liabilities, either directly or indirectly (such as interest rates, yield curves, and prepayment speeds). • Level 3 – inputs to the valuation methodology are unobservable and significant to the fair value. These may be internally developed, using the Company’s best information and assumptions that a market participant would consider. The valuation methodologies for assets and liabilities measured at fair value on a recurring and non-recurring basis are described in the Fair Value Measurements note in the Company's 2016 Annual Report on Form 10-K. There have been no significant changes in these methodologies since then, except for a change in the valuation of cleared interest rate swaps as discussed in Note 10. Instruments Measured at Fair Value on a Recurring Basis The table below presents the September 30, 2017 and December 31, 2016 carrying values of assets and liabilities measured at fair value on a recurring basis. There were no transfers among levels during the first nine months of 2017 or the year ended December 31, 2016 . Fair Value Measurements Using (In thousands) Total Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) September 30, 2017 Assets: Residential mortgage loans held for sale $ 11,320 $ — $ 11,320 $ — Available for sale securities: U.S. government and federal agency obligations 918,604 918,604 — — Government-sponsored enterprise obligations 469,414 — 469,414 — State and municipal obligations 1,720,403 — 1,703,550 16,853 Agency mortgage-backed securities 2,756,973 — 2,756,973 — Non-agency mortgage-backed securities 1,066,764 — 1,066,764 — Asset-backed securities 1,736,966 — 1,736,966 — Other debt securities 356,641 — 356,641 — Equity securities 83,522 32,915 50,607 — Trading securities 24,605 — 24,605 — Private equity investments 50,254 — — 50,254 Derivatives * 11,650 — 10,837 813 Assets held in trust for deferred compensation plan 12,311 12,311 — — Total assets 9,219,427 963,830 8,187,677 67,920 Liabilities: Derivatives * 5,979 — 5,850 129 Liabilities held in trust for deferred compensation plan 12,311 12,311 — — Total liabilities $ 18,290 $ 12,311 $ 5,850 $ 129 December 31, 2016 Assets: Residential mortgage loans held for sale $ 9,263 $ — $ 9,263 $ — Available for sale securities: U.S. government and federal agency obligations 920,904 920,904 — — Government-sponsored enterprise obligations 449,998 — 449,998 — State and municipal obligations 1,778,214 — 1,761,532 16,682 Agency mortgage-backed securities 2,685,931 — 2,685,931 — Non-agency mortgage-backed securities 1,055,639 — 1,055,639 — Asset-backed securities 2,381,301 — 2,381,301 — Other debt securities 325,953 — 325,953 — Equity securities 51,263 24,967 26,296 — Trading securities 22,225 — 22,225 — Private equity investments 50,820 — — 50,820 Derivatives * 13,566 — 13,146 420 Assets held in trust for deferred compensation plan 10,261 10,261 — — Total assets 9,755,338 956,132 8,731,284 67,922 Liabilities: Derivatives * 13,339 — 13,177 162 Liabilities held in trust for deferred compensation plan 10,261 10,261 — — Total liabilities $ 23,600 $ 10,261 $ 13,177 $ 162 * The fair value of each class of derivative is shown in Note 10. The changes in Level 3 assets and liabilities measured at fair value on a recurring basis are summarized as follows: Fair Value Measurements Using Significant Unobservable Inputs (Level 3) (In thousands) State and Municipal Obligations Private Equity Investments Derivatives Total For the three months ended September 30, 2017 Balance June 30, 2017 $ 16,825 $ 53,557 $ 791 $ 71,173 Total gains or losses (realized/unrealized): Included in earnings — (5,198 ) (107 ) (5,305 ) Included in other comprehensive income * 19 — — 19 Discount accretion 9 — — 9 Purchases of private equity investments — 2,185 — 2,185 Sale/pay down of private equity investments — (290 ) — (290 ) Balance September 30, 2017 $ 16,853 $ 50,254 $ 684 $ 67,791 Total gains or losses for the three months included in earnings attributable to the change in unrealized gains or losses relating to assets still held at September 30, 2017 $ — $ (5,198 ) $ 764 $ (4,434 ) For the nine months ended September 30, 2017 Balance January 1, 2017 $ 16,682 $ 50,820 $ 258 $ 67,760 Total gains or losses (realized/unrealized): Included in earnings — (8,028 ) 426 (7,602 ) Included in other comprehensive income * 729 — — 729 Investment securities called (600 ) — — (600 ) Discount accretion 42 — — 42 Purchases of private equity investments — 9,269 — 9,269 Sale/pay down of private equity investments — (1,840 ) — (1,840 ) Capitalized interest/dividends — 33 — 33 Balance September 30, 2017 $ 16,853 $ 50,254 $ 684 $ 67,791 Total gains or losses for the nine months included in earnings attributable to the change in unrealized gains or losses relating to assets still held at September 30, 2017 $ — $ (7,853 ) $ 775 $ (7,078 ) For the three months ended September 30, 2016 Balance June 30, 2016 $ 17,679 $ 62,813 $ 502 $ 80,994 Total gains or losses (realized/unrealized): Included in earnings — (2,921 ) 136 (2,785 ) Included in other comprehensive income * 317 — — 317 Investment securities called (1,100 ) — — (1,100 ) Discount accretion 12 — — 12 Purchases of private equity investments — 2,894 — 2,894 Sale/pay down of private equity investments — (3,315 ) — (3,315 ) Capitalized interest/dividends — 15 — 15 Sale of risk participation agreement — — (33 ) (33 ) Balance September 30, 2016 $ 16,908 $ 59,486 $ 605 $ 76,999 Total gains or losses for the three months included in earnings attributable to the change in unrealized gains or losses relating to assets still held at September 30, 2016 $ — $ (2,921 ) $ 926 $ (1,995 ) For the nine months ended September 30, 2016 Balance January 1, 2016 $ 17,195 $ 63,032 $ 69 $ 80,296 Total gains or losses (realized/unrealized): Included in earnings — (6,645 ) 605 (6,040 ) Included in other comprehensive income * 819 — — 819 Investment securities called (1,200 ) — — (1,200 ) Discount accretion 94 — — 94 Purchases of private equity investments — 8,735 — 8,735 Sale/pay down of private equity investments — (5,713 ) — (5,713 ) Capitalized interest/dividends — 77 — 77 Sale of risk participation agreement — — (69 ) (69 ) Balance September 30, 2016 $ 16,908 $ 59,486 $ 605 $ 76,999 Total gains or losses for the nine months included in earnings attributable to the change in unrealized gains or losses relating to assets still held at September 30, 2016 $ — $ (6,545 ) $ 868 $ (5,677 ) * Included in "net unrealized gains (losses) on other securities" in the consolidated statements of comprehensive income. Gains and losses included in earnings for the Level 3 assets and liabilities in the previous table are reported in the following line items in the consolidated statements of income: (In thousands) Loan Fees and Sales Other Non-Interest Income Investment Securities Gains (Losses), Net Total For the three months ended September 30, 2017 Total gains or losses included in earnings $ (115 ) $ 8 $ (5,198 ) $ (5,305 ) Change in unrealized gains or losses relating to assets still held at September 30, 2017 $ 756 $ 8 $ (5,198 ) $ (4,434 ) For the nine months ended September 30, 2017 Total gains or losses included in earnings $ 407 $ 19 $ (8,028 ) $ (7,602 ) Change in unrealized gains or losses relating to assets still held at September 30, 2017 $ 756 $ 19 $ (7,853 ) $ (7,078 ) For the three months ended September 30, 2016 Total gains or losses included in earnings $ 86 $ 50 $ (2,921 ) $ (2,785 ) Change in unrealized gains or losses relating to assets still held at September 30, 2016 $ 876 $ 50 $ (2,921 ) $ (1,995 ) For the nine months ended September 30, 2016 Total gains or losses included in earnings $ 613 $ (8 ) $ (6,645 ) $ (6,040 ) Change in unrealized gains or losses relating to assets still held at September 30, 2016 $ 876 $ (8 ) $ (6,545 ) $ (5,677 ) Level 3 Inputs The Company's significant Level 3 measurements which employ unobservable inputs that are readily quantifiable pertain to auction rate securities (ARS) held by the Bank, investments in portfolio concerns held by the Company's private equity subsidiaries, and held for sale residential mortgage loan commitments. ARS are included in state and municipal securities and totaled $16.9 million at September 30, 2017 , while private equity investments, included in non-marketable securities, totaled $50.3 million . Information about these inputs is presented in the table and discussions below. Quantitative Information about Level 3 Fair Value Measurements Weighted Valuation Technique Unobservable Input Range Average Auction rate securities Discounted cash flow Estimated market recovery period 5 years Estimated market rate 2.8% - 3.1% Private equity investments Market comparable companies EBITDA multiple 4.0 - 5.8 Mortgage loan commitments Discounted cash flow Probability of funding 50.9% - 100.0% 79.1% Embedded servicing value (.3)% - 2.2% 1.1% Instruments Measured at Fair Value on a Nonrecurring Basis For assets measured at fair value on a nonrecurring basis during the first nine months of 2017 and 2016 , and still held as of September 30, 2017 and 2016 , the following table provides the adjustments to fair value recognized during the respective periods, the level of valuation inputs used to determine each adjustment, and the carrying value of the related individual assets or portfolios at September 30, 2017 and 2016 . Fair Value Measurements Using (In thousands) Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Gains (Losses) Recognized During the Nine Months Ended September 30 September 30, 2017 Collateral dependent impaired loans $ 1,468 $ — $ — $ 1,468 $ (336 ) Mortgage servicing rights 4,245 — — 4,245 6 Foreclosed assets 50 — — 50 (83 ) Long-lived assets 3,033 — — 3,033 (1,167 ) September 30, 2016 Collateral dependent impaired loans $ 1,756 $ — $ — $ 1,756 $ (1,626 ) Mortgage servicing rights 2,533 — — 2,533 (7 ) Foreclosed assets 47 — — 47 (66 ) Long-lived assets 2,232 — — 2,232 (1,001 )

Fair Value Of Financial Instrum

Fair Value Of Financial Instruments	9 Months Ended
	Sep. 30, 2017
Fair Value Of Financial Instruments [Abstract]
Fair Value Of Financial Instruments	Fair Value of Financial Instruments The carrying amounts and estimated fair values of financial instruments held by the Company are set forth below. Fair value estimates are made at a specific point in time based on relevant market information. They do not reflect any premium or discount that could result from offering for sale at one time the Company’s entire holdings of a particular financial instrument. Because no market exists for many of the Company’s financial instruments, fair value estimates are based on judgments regarding future expected loss experience, risk characteristics and economic conditions. These estimates are subjective, involve uncertainties, and cannot be determined with precision. Changes in assumptions could significantly affect the estimates. The methods and inputs used in the estimation of fair value for the financial instruments in the table below are discussed in the Fair Value Measurements and the Fair Value of Financial Instruments notes in the Company's 2016 Annual Report on Form 10-K. There have been no significant changes in these methods and inputs since December 31, 2016 , except as mentioned in Note 10 on Derivatives. The estimated fair values of the Company’s financial instruments and the classification of their fair value measurement within the valuation hierarchy are as follows: Fair Value Hierarchy Level September 30, 2017 December 31, 2016 (In thousands) Carrying Amount Estimated Fair Value Carrying Amount Estimated Fair Value Financial Assets Loans: Business Level 3 $ 4,834,037 $ 4,848,169 $ 4,776,365 $ 4,787,469 Real estate - construction and land Level 3 921,609 933,862 791,236 800,426 Real estate - business Level 3 2,700,174 2,712,002 2,643,374 2,658,093 Real estate - personal Level 3 2,029,302 2,034,374 2,010,397 2,005,227 Consumer Level 3 2,113,438 2,088,302 1,990,801 1,974,784 Revolving home equity Level 3 391,308 391,419 413,634 414,499 Consumer credit card Level 3 752,379 767,344 776,465 794,856 Overdrafts Level 3 3,245 3,245 10,464 10,464 Loans held for sale Level 2 17,337 17,337 14,456 14,456 Investment securities: Available for sale Level 1 951,519 951,519 945,871 945,871 Available for sale Level 2 8,140,915 8,140,915 8,686,650 8,686,650 Available for sale Level 3 16,853 16,853 16,682 16,682 Trading Level 2 24,605 24,605 22,225 22,225 Non-marketable Level 3 99,268 99,268 99,558 99,558 Federal funds sold Level 1 32,630 32,630 15,470 15,470 Securities purchased under agreements to resell Level 3 700,000 702,989 725,000 728,179 Interest earning deposits with banks Level 1 105,422 105,422 272,275 272,275 Cash and due from banks Level 1 461,724 461,724 494,690 494,690 Derivative instruments Level 2 10,837 10,837 13,146 13,146 Derivative instruments Level 3 813 813 420 420 Assets held in trust for deferred compensation plan Level 1 12,311 12,311 10,261 10,261 Financial Liabilities Non-interest bearing deposits Level 1 $ 7,536,127 $ 7,536,127 $ 7,429,398 $ 7,429,398 Savings, interest checking and money market deposits Level 1 11,091,200 11,091,200 11,430,789 11,430,789 Time open and certificates of deposit Level 3 1,816,446 1,820,178 2,240,908 2,235,218 Federal funds purchased Level 1 350,910 350,910 52,840 52,840 Securities sold under agreements to repurchase Level 3 1,058,074 1,058,459 1,671,065 1,671,227 Other borrowings Level 3 102,553 103,012 102,049 104,298 Derivative instruments Level 2 5,850 5,850 13,177 13,177 Derivative instruments Level 3 129 129 162 162 Liabilities held in trust for deferred compensation plan Level 1 12,311 12,311 10,261 10,261

Legal and Regulatory Proceeding

Legal and Regulatory Proceedings (Notes)	9 Months Ended
	Sep. 30, 2017
Legal Proceedings [Abstract]
Legal Matters and Contingencies [Text Block]	Legal and Regulatory Proceedings On August 15, 2014, a customer filed a class action complaint against Commerce Bank in the Circuit Court, Jackson County, Missouri. The case is Cassandra Warren, et al v. Commerce Bank (Case No. 1416-CV19197). In the case, the customer alleged violation of the Missouri usury statue in connection with Commerce Bank charging overdraft fees in connection with point-of-sale/debit and automated-teller machine cards. On August 31, 2017, the Court ruled in favor of Commerce Bank on its motion for summary judgment. The time period for any appeal on the summary judgment ruling has run with no appeal filed; accordingly, the case has been concluded with no liability to Commerce Bank. The Company has various other legal proceedings pending at September 30, 2017 , arising in the normal course of business. While some matters pending against the Company specify damages claimed by plaintiffs, others do not seek a specified amount of damages or are at very early stages of the legal process. The Company records a loss accrual for all legal and regulatory matters for which it deems a loss is probable and can be reasonably estimated. Some matters, which are in the early stages, have not yet progressed to the point where a loss amount can be determined to be probable and estimable.

Loans And Allowance For Loan 24

Loans And Allowance For Loan Losses (Tables)	9 Months Ended
	Sep. 30, 2017
Loans And Allowance For Loan Losses [Abstract]
Summary Classification Of Held To Maturity Loan Portfolio	Major classifications within the Company’s held for investment loan portfolio at September 30, 2017 and December 31, 2016 are as follows: (In thousands) September 30, 2017 December 31, 2016 Commercial: Business $ 4,834,037 $ 4,776,365 Real estate – construction and land 921,609 791,236 Real estate – business 2,700,174 2,643,374 Personal Banking: Real estate – personal 2,029,302 2,010,397 Consumer 2,113,438 1,990,801 Revolving home equity 391,308 413,634 Consumer credit card 752,379 776,465 Overdrafts 3,245 10,464 Total loans $ 13,745,492 $ 13,412,736
Summary Of Activity In The Allowance For Loan Losses	A summary of the activity in the allowance for loan losses during the three and nine months ended September 30, 2017 and 2016 , respectively, follows: For the Three Months Ended September 30 For the Nine Months Ended September 30 (In thousands) Commercial Personal Banking Total Commercial Personal Banking Total Balance at beginning of period $ 92,739 $ 65,093 $ 157,832 $ 91,361 $ 64,571 $ 155,932 Provision 24 10,680 10,704 1,026 31,564 32,590 Deductions: Loans charged off 378 13,592 13,970 1,455 39,337 40,792 Less recoveries on loans 651 2,615 3,266 2,104 7,998 10,102 Net loan charge-offs (recoveries) (273 ) 10,977 10,704 (649 ) 31,339 30,690 Balance September 30, 2017 $ 93,036 $ 64,796 $ 157,832 $ 93,036 $ 64,796 $ 157,832 Balance at beginning of period $ 89,198 $ 64,634 $ 153,832 $ 82,086 $ 69,446 $ 151,532 Provision (1,411 ) 8,674 7,263 4,309 21,609 25,918 Deductions: Loans charged off 291 11,872 12,163 2,465 35,633 38,098 Less recoveries on loans 2,759 2,841 5,600 6,325 8,855 15,180 Net loan charge-offs (recoveries) (2,468 ) 9,031 6,563 (3,860 ) 26,778 22,918 Balance September 30, 2016 $ 90,255 $ 64,277 $ 154,532 $ 90,255 $ 64,277 $ 154,532
Allowance For Loan Losses And Related Loan Balance Disaggregated On The Basis Of Impairment Methodology	The following table shows the balance in the allowance for loan losses and the related loan balance at September 30, 2017 and December 31, 2016 , disaggregated on the basis of impairment methodology. Impaired loans evaluated under ASC 310-10-35 include loans on non-accrual status, which are individually evaluated for impairment, and other impaired loans discussed below, which are deemed to have similar risk characteristics and are collectively evaluated. All other loans are collectively evaluated for impairment under ASC 450-20. Impaired Loans All Other Loans (In thousands) Allowance for Loan Losses Loans Outstanding Allowance for Loan Losses Loans Outstanding September 30, 2017 Commercial $ 1,789 $ 55,969 $ 91,247 $ 8,399,851 Personal Banking 1,322 23,571 63,474 5,266,101 Total $ 3,111 $ 79,540 $ 154,721 $ 13,665,952 December 31, 2016 Commercial $ 1,817 $ 44,795 $ 89,544 $ 8,166,180 Personal Banking 1,292 19,737 63,279 5,182,024 Total $ 3,109 $ 64,532 $ 152,823 $ 13,348,204
Investment In Impaired Loans	The table below shows the Company’s investment in impaired loans at September 30, 2017 and December 31, 2016 . These loans consist of all loans on non-accrual status and other restructured loans whose terms have been modified and classified as troubled debt restructurings. These restructured loans are performing in accordance with their modified terms, and because the Company believes it probable that all amounts due under the modified terms of the agreements will be collected, interest on these loans is being recognized on an accrual basis. They are discussed further in the "Troubled debt restructurings" section on page 14. (In thousands) Sept. 30, 2017 Dec. 31, 2016 Non-accrual loans $ 13,640 $ 14,283 Restructured loans (accruing) 65,900 50,249 Total impaired loans $ 79,540 $ 64,532
Additional Information About Impaired Loans Held	The following table provides additional information about impaired loans held by the Company at September 30, 2017 and December 31, 2016 , segregated between loans for which an allowance for credit losses has been provided and loans for which no allowance has been provided. (In thousands) Recorded Investment Unpaid Principal Balance Related Allowance September 30, 2017 With no related allowance recorded: Business $ 6,196 $ 9,725 $ — Real estate – business 587 587 — Consumer 1,023 1,047 — $ 7,806 $ 11,359 $ — With an allowance recorded: Business $ 35,708 $ 36,219 $ 1,141 Real estate – construction and land 1,367 1,595 37 Real estate – business 12,111 13,319 611 Real estate – personal 9,723 12,537 607 Consumer 5,232 5,271 52 Revolving home equity 578 578 5 Consumer credit card 7,015 7,015 658 $ 71,734 $ 76,534 $ 3,111 Total $ 79,540 $ 87,893 $ 3,111 December 31, 2016 With no related allowance recorded: Business $ 7,375 $ 10,470 $ — Real estate – construction and land 557 752 — $ 7,932 $ 11,222 $ — With an allowance recorded: Business $ 29,924 $ 31,795 $ 1,318 Real estate – construction and land 69 72 3 Real estate – business 6,870 8,072 496 Real estate – personal 6,394 9,199 642 Consumer 5,281 5,281 57 Revolving home equity 584 584 1 Consumer credit card 7,478 7,478 592 $ 56,600 $ 62,481 $ 3,109 Total $ 64,532 $ 73,703 $ 3,109
Total Average Impaired Loans	Total average impaired loans for the three and nine month periods ended September 30, 2017 and 2016 , respectively, are shown in the table below. (In thousands) Commercial Personal Banking Total Average Impaired Loans: For the three months ended September 30, 2017 Non-accrual loans $ 8,938 $ 4,238 $ 13,176 Restructured loans (accruing) 42,930 18,691 61,621 Total $ 51,868 $ 22,929 $ 74,797 For the nine months ended September 30, 2017 Non-accrual loans $ 9,800 $ 4,098 $ 13,898 Restructured loans (accruing) 36,567 16,901 53,468 Total $ 46,367 $ 20,999 $ 67,366 For the three months ended September 30, 2016 Non-accrual loans $ 15,106 $ 3,928 $ 19,034 Restructured loans (accruing) 31,372 17,082 48,454 Total $ 46,478 $ 21,010 $ 67,488 For the nine months ended September 30, 2016 Non-accrual loans $ 19,387 $ 4,336 $ 23,723 Restructured loans (accruing) 29,117 17,359 46,476 Total $ 48,504 $ 21,695 $ 70,199
Interest Income Recognized On Impaired Loans	The table below shows interest income recognized during the three and nine month periods ended September 30, 2017 and 2016 , respectively, for impaired loans held at the end of each period. This interest all relates to accruing restructured loans, as discussed in the "Troubled debt restructurings" section on page 14. For the Three Months Ended September 30 For the Nine Months Ended September 30 (In thousands) 2017 2016 2017 2016 Interest income recognized on impaired loans: Business $ 473 $ 277 $ 1,418 $ 830 Real estate – construction and land 10 2 30 7 Real estate – business 118 42 354 126 Real estate – personal 104 39 311 118 Consumer 79 89 236 267 Revolving home equity 7 7 20 22 Consumer credit card 162 174 486 522 Total $ 953 $ 630 $ 2,855 $ 1,892
Aging Information On Past Due And Nonaccrual Loans	The following table provides aging information on the Company’s past due and accruing loans, in addition to the balances of loans on non-accrual status, at September 30, 2017 and December 31, 2016 . (In thousands) Current or Less Than 30 Days Past Due 30 – 89 Days Past Due 90 Days Past Due and Still Accruing Non-accrual Total September 30, 2017 Commercial: Business $ 4,823,779 $ 2,630 $ 807 $ 6,821 $ 4,834,037 Real estate – construction and land 917,128 3,913 35 533 921,609 Real estate – business 2,688,625 8,580 623 2,346 2,700,174 Personal Banking: Real estate – personal 2,013,632 11,141 1,666 2,863 2,029,302 Consumer 2,082,203 27,450 2,708 1,077 2,113,438 Revolving home equity 388,346 1,530 1,432 — 391,308 Consumer credit card 734,215 8,971 9,193 — 752,379 Overdrafts 2,933 312 — — 3,245 Total $ 13,650,861 $ 64,527 $ 16,464 $ 13,640 $ 13,745,492 December 31, 2016 Commercial: Business $ 4,763,274 $ 3,735 $ 674 $ 8,682 $ 4,776,365 Real estate – construction and land 789,633 1,039 — 564 791,236 Real estate – business 2,639,586 2,154 — 1,634 2,643,374 Personal Banking: Real estate – personal 1,995,724 9,162 2,108 3,403 2,010,397 Consumer 1,957,358 29,783 3,660 — 1,990,801 Revolving home equity 411,483 1,032 1,119 — 413,634 Consumer credit card 757,443 10,187 8,835 — 776,465 Overdrafts 10,014 450 — — 10,464 Total $ 13,324,515 $ 57,542 $ 16,396 $ 14,283 $ 13,412,736
Credit Quality Of Commercial Loan Portfolio	The following table provides information about the credit quality of the Commercial loan portfolio, using the Company’s internal rating system as an indicator. The internal rating system is a series of grades reflecting management’s risk assessment, based on its analysis of the borrower’s financial condition. The “pass” category consists of a range of loan grades that reflect increasing, though still acceptable, risk. Movement of risk through the various grade levels in the “pass” category is monitored for early identification of credit deterioration. The “special mention” rating is applied to loans where the borrower exhibits negative financial trends due to borrower specific or systemic conditions that, if left uncorrected, threaten its capacity to meet its debt obligations. The borrower is believed to have sufficient financial flexibility to react to and resolve its negative financial situation. It is a transitional grade that is closely monitored for improvement or deterioration. The “substandard” rating is applied to loans where the borrower exhibits well-defined weaknesses that jeopardize its continued performance and are of a severity that the distinct possibility of default exists. Loans are placed on “non-accrual” when management does not expect to collect payments consistent with acceptable and agreed upon terms of repayment. Commercial Loans (In thousands) Business Real Estate-Construction Real Estate- Business Total September 30, 2017 Pass $ 4,593,958 $ 915,279 $ 2,586,349 $ 8,095,586 Special mention 123,549 2,527 57,319 183,395 Substandard 109,709 3,270 54,160 167,139 Non-accrual 6,821 533 2,346 9,700 Total $ 4,834,037 $ 921,609 $ 2,700,174 $ 8,455,820 December 31, 2016 Pass $ 4,607,553 $ 788,778 $ 2,543,348 $ 7,939,679 Special mention 116,642 722 45,479 162,843 Substandard 43,488 1,172 52,913 97,573 Non-accrual 8,682 564 1,634 10,880 Total $ 4,776,365 $ 791,236 $ 2,643,374 $ 8,210,975
Summary Of Loans In The Personal Banking Portfolio Percentage Of Balances Outstanding	For the remainder of loans in the Personal Banking portfolio, the table below shows the percentage of balances outstanding at September 30, 2017 and December 31, 2016 by FICO score. Personal Banking Loans % of Loan Category Real Estate - Personal Consumer Revolving Home Equity Consumer Credit Card September 30, 2017 FICO score: Under 600 1.4 % 3.3 % .9 % 5.0 % 600 - 659 2.2 5.7 2.1 15.1 660 - 719 10.1 17.1 9.0 34.9 720 - 779 24.8 26.1 21.2 25.9 780 and over 61.5 47.8 66.8 19.1 Total 100.0 % 100.0 % 100.0 % 100.0 % December 31, 2016 FICO score: Under 600 1.3 % 3.4 % 1.0 % 4.9 % 600 - 659 2.6 6.4 1.8 15.5 660 - 719 10.4 19.7 9.7 34.9 720 - 779 25.4 26.3 21.1 25.1 780 and over 60.3 44.2 66.4 19.6 Total 100.0 % 100.0 % 100.0 % 100.0 %
Outstanding Balance Of Loans Classified As Troubled Debt Restructurings	The following table shows the outstanding balances of loans classified as troubled debt restructurings at September 30, 2017 , in addition to the outstanding balances of these restructured loans which the Company considers to have been in default at any time during the past twelve months. For purposes of this disclosure, the Company considers "default" to mean 90 days or more past due as to interest or principal. (In thousands) September 30, 2017 Balance 90 days past due at any time during previous 12 months Commercial: Business $ 40,608 $ — Real estate - construction and land 1,304 — Real estate - business 10,353 623 Personal Banking: Real estate - personal 7,996 397 Consumer 5,235 32 Revolving home equity 578 42 Consumer credit card 7,015 800 Total restructured loans $ 73,089 $ 1,894

Investment Securities (Tables)

Investment Securities (Tables)	9 Months Ended
	Sep. 30, 2017
Investment Securities [Abstract]
Investment Securities, At Fair Value	nvestment securities, at fair value, consisted of the following at September 30, 2017 and December 31, 2016 . (In thousands) Sept. 30, 2017 December 31, 2016 Available for sale $ 9,109,287 $ 9,649,203 Trading 24,605 22,225 Non-marketable 99,268 99,558 Total investment securities $ 9,233,160 $ 9,770,986
Summary Of Available For Sale Investment Securities By Maturity Groupings	A summary of the available for sale investment securities by maturity groupings as of September 30, 2017 is shown below. The investment portfolio includes agency mortgage-backed securities, which are guaranteed by agencies such as the FHLMC, FNMA, GNMA and FDIC, in addition to non-agency mortgage-backed securities, which have no guarantee but are collateralized by commercial and residential mortgages. Also included are certain other asset-backed securities, which are primarily collateralized by credit cards, automobiles, student loans, and commercial loans. These securities differ from traditional debt securities primarily in that they may have uncertain maturity dates and are priced based on estimated prepayment rates on the underlying collateral. (In thousands) Amortized Cost Fair Value U.S. government and federal agency obligations: Within 1 year $ 57,511 $ 58,238 After 1 but within 5 years 570,284 573,789 After 5 but within 10 years 218,912 219,468 After 10 years 69,517 67,109 Total U.S. government and federal agency obligations 916,224 918,604 Government-sponsored enterprise obligations: Within 1 year 187,032 187,027 After 1 but within 5 years 247,444 247,141 After 10 years 35,927 35,246 Total government-sponsored enterprise obligations 470,403 469,414 State and municipal obligations: Within 1 year 177,616 178,836 After 1 but within 5 years 659,012 671,931 After 5 but within 10 years 800,504 819,943 After 10 years 50,004 49,693 Total state and municipal obligations 1,687,136 1,720,403 Mortgage and asset-backed securities: Agency mortgage-backed securities 2,741,329 2,756,973 Non-agency mortgage-backed securities 1,062,079 1,066,764 Asset-backed securities 1,735,004 1,736,966 Total mortgage and asset-backed securities 5,538,412 5,560,703 Other debt securities: Within 1 year 13,388 13,393 After 1 but within 5 years 207,556 210,022 After 5 but within 10 years 133,140 133,226 Total other debt securities 354,084 356,641 Equity securities 5,353 83,522 Total available for sale investment securities $ 8,971,612 $ 9,109,287
Available For Sale Securities Unrealized Gains And Losses By Security Type	For securities classified as available for sale, the following table shows the unrealized gains and losses (pre-tax) in accumulated other comprehensive income, by security type. (In thousands) Amortized Cost Gross Gross Fair Value September 30, 2017 U.S. government and federal agency obligations $ 916,224 $ 6,359 $ (3,979 ) $ 918,604 Government-sponsored enterprise obligations 470,403 844 (1,833 ) 469,414 State and municipal obligations 1,687,136 34,952 (1,685 ) 1,720,403 Mortgage and asset-backed securities: Agency mortgage-backed securities 2,741,329 28,827 (13,183 ) 2,756,973 Non-agency mortgage-backed securities 1,062,079 8,536 (3,851 ) 1,066,764 Asset-backed securities 1,735,004 5,047 (3,085 ) 1,736,966 Total mortgage and asset-backed securities 5,538,412 42,410 (20,119 ) 5,560,703 Other debt securities 354,084 3,293 (736 ) 356,641 Equity securities 5,353 78,169 — 83,522 Total $ 8,971,612 $ 166,027 $ (28,352 ) $ 9,109,287 December 31, 2016 U.S. government and federal agency obligations $ 919,904 $ 7,312 $ (6,312 ) $ 920,904 Government-sponsored enterprise obligations 450,448 1,126 (1,576 ) 449,998 State and municipal obligations 1,778,684 12,223 (12,693 ) 1,778,214 Mortgage and asset-backed securities: Agency mortgage-backed securities 2,674,964 31,610 (20,643 ) 2,685,931 Non-agency mortgage-backed securities 1,054,446 7,686 (6,493 ) 1,055,639 Asset-backed securities 2,389,176 3,338 (11,213 ) 2,381,301 Total mortgage and asset-backed securities 6,118,586 42,634 (38,349 ) 6,122,871 Other debt securities 327,030 935 (2,012 ) 325,953 Equity securities 5,678 45,585 — 51,263 Total $ 9,600,330 $ 109,815 $ (60,942 ) $ 9,649,203
Cash Flow Model Inputs Used To Calculate Credit Losses	ignificant inputs to the cash flow models used to calculate the credit losses on these securities at September 30, 2017 included the following: Significant Inputs Range Prepayment CPR 3% - 25% Projected cumulative default 13% - 50% Credit support 0% - 47% Loss severity 16% - 63%
Changes In Recorded Credit Losses	The following table presents a rollforward of the cumulative OTTI credit losses recognized in earnings on all available for sale debt securities. For the Nine Months Ended September 30 (In thousands) 2017 2016 Cumulative OTTI credit losses at January 1 $ 14,080 $ 14,129 Credit losses on debt securities for which impairment was not previously recognized 98 — Credit losses on debt securities for which impairment was previously recognized 274 270 Increase in expected cash flows that are recognized over remaining life of security (207 ) (171 ) Cumulative OTTI credit losses at September 30 $ 14,245 $ 14,228
Securities With Unrealized Losses And Length Of Impairment Period	Securities with unrealized losses recorded in accumulated other comprehensive income are shown in the table below, along with the length of the impairment period. Less than 12 months 12 months or longer Total (In thousands) Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses September 30, 2017 U.S. government and federal agency obligations $ 123,071 $ 3,979 $ — $ — $ 123,071 $ 3,979 Government-sponsored enterprise obligations 190,141 1,650 49,793 183 239,934 1,833 State and municipal obligations 95,890 692 38,026 993 133,916 1,685 Mortgage and asset-backed securities: Agency mortgage-backed securities 887,047 9,741 223,550 3,442 1,110,597 13,183 Non-agency mortgage-backed securities 381,896 1,674 156,455 2,177 538,351 3,851 Asset-backed securities 488,409 522 279,402 2,563 767,811 3,085 Total mortgage and asset-backed securities 1,757,352 11,937 659,407 8,182 2,416,759 20,119 Other debt securities 70,143 622 9,363 114 79,506 736 Total $ 2,236,597 $ 18,880 $ 756,589 $ 9,472 $ 2,993,186 $ 28,352 December 31, 2016 U.S. government and federal agency obligations $ 349,538 $ 2,823 $ 32,208 $ 3,489 $ 381,746 $ 6,312 Government-sponsored enterprise obligations 190,441 1,576 — — 190,441 1,576 State and municipal obligations 700,779 12,164 15,195 529 715,974 12,693 Mortgage and asset-backed securities: Agency mortgage-backed securities 1,147,416 20,638 2,150 5 1,149,566 20,643 Non-agency mortgage-backed securities 688,131 6,373 34,946 120 723,077 6,493 Asset-backed securities 780,209 5,277 358,778 5,936 1,138,987 11,213 Total mortgage and asset-backed securities 2,615,756 32,288 395,874 6,061 3,011,630 38,349 Other debt securities 179,639 1,986 975 26 180,614 2,012 Total $ 4,036,153 $ 50,837 $ 444,252 $ 10,105 $ 4,480,405 $ 60,942
Proceeds From Sales Of Securities And Components Of Investment Securities Gains And Losses	The following tables present proceeds from sales of securities and the components of investment securities gains and losses which have been recognized in earnings. For the Nine Months Ended September 30 (In thousands) 2017 2016 Proceeds from sales of securities: Available for sale $ 367,453 $ — Non-marketable 1,583 7,946 Total proceeds $ 369,036 $ 7,946 Investment securities gains (losses), net: Available for sale: Losses realized on called bonds $ (254 ) $ — Gains realized on sales 592 — Losses realized on sales (568 ) — Gains realized on donations of securities 6,707 — Other-than-temporary impairment recognized on debt securities (372 ) (270 ) Non-marketable: Gains realized on sales 645 3,717 Losses realized on sales (880 ) (502 ) Fair value adjustments, net (8,028 ) (6,649 ) Total gains (losses), net $ (2,158 ) $ (3,704 )

Goodwill And Other Intangible26

Goodwill And Other Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule Of Intangible Assets With Estimable Useful Lives	The following table presents information about the Company's intangible assets which have estimable useful lives. September 30, 2017 December 31, 2016 (In thousands) Gross Carrying Amount Accumulated Amortization Valuation Allowance Net Amount Gross Carrying Amount Accumulated Amortization Valuation Allowance Net Amount Amortizable intangible assets: Core deposit premium $ 31,270 $ (28,127 ) $ — $ 3,143 $ 31,270 $ (27,429 ) $ — $ 3,841 Mortgage servicing rights 7,361 (3,100 ) (16 ) 4,245 5,672 (2,782 ) (22 ) 2,868 Total $ 38,631 $ (31,227 ) $ (16 ) $ 7,388 $ 36,942 $ (30,211 ) $ (22 ) $ 6,709
Schedule of Estimated Annual Amortization Expense	he following table shows the estimated annual amortization expense for the next five fiscal years. This expense is based on existing asset balances and the interest rate environment as of September 30, 2017 . The Company’s actual amortization expense in any given period may be different from the estimated amounts depending upon the acquisition of intangible assets, changes in mortgage interest rates, prepayment rates and other market conditions. (In thousands) 2017 $ 1,331 2018 1,181 2019 996 2020 834 2021 711
Schedule Of Changes In CArrying Amount Of Goodwill And Net Other Intangible Assets	Changes in the carrying amount of goodwill and net other intangible assets for the nine month period ended September 30, 2017 is as follows: (In thousands) Goodwill Core Deposit Premium Mortgage Servicing Rights Balance January 1, 2017 $ 138,921 $ 3,841 $ 2,868 Originations — — 1,689 Amortization — (698 ) (318 ) Impairment reversal — — 6 Balance September 30, 2017 $ 138,921 $ 3,143 $ 4,245
Schedule Of Goodwill Allocated By Operating Segments	Goodwill allocated to the Company’s operating segments at September 30, 2017 and December 31, 2016 is shown below. (In thousands) Consumer segment $ 70,721 Commercial segment 67,454 Wealth segment 746 Total goodwill $ 138,921

Pension (Tables)

Pension (Tables)	9 Months Ended
	Sep. 30, 2017
Pension [Abstract]
Net Pension Cost	The amount of net pension cost is shown in the table below: For the Three Months Ended September 30 For the Nine Months Ended September 30 (In thousands) 2017 2016 2017 2016 Service cost - benefits earned during the period $ 193 $ 135 $ 450 $ 406 Interest cost on projected benefit obligation 923 986 2,869 2,958 Expected return on plan assets (1,463 ) (1,437 ) (4,339 ) (4,313 ) Amortization of prior service cost (67 ) (68 ) (203 ) (203 ) Amortization of unrecognized net loss 630 647 1,864 1,940 Net periodic pension cost $ 216 $ 263 $ 641 $ 788

Common Stock (Tables)

Common Stock (Tables)	9 Months Ended
	Sep. 30, 2017
Common Stock [Abstract]
Summary Of Components Used To Calculate Basic And Diluted Income Per Share	Presented below is a summary of the components used to calculate basic and diluted income per share. The Company applies the two-class method of computing income per share, as nonvested share-based awards that contain nonforfeitable rights to dividends are considered securities which participate in undistributed earnings with common stock. The two-class method requires the calculation of separate income per share amounts for the nonvested share-based awards and for common stock. Income per share attributable to common stock is shown in the table below. Nonvested share-based awards are further discussed in Note 12. For the Three Months Ended September 30 For the Nine Months Ended September 30 (In thousands, except per share data) 2017 2016 2017 2016 Basic income per common share: Net income attributable to Commerce Bancshares, Inc. $ 74,564 $ 68,545 $ 225,028 $ 203,812 Less preferred stock dividends 2,250 2,250 6,750 6,750 Net income available to common shareholders $ 72,314 $ 66,295 218,278 197,062 Less income allocated to nonvested restricted stock 862 913 2,750 2,747 Net income allocated to common stock $ 71,452 $ 65,382 $ 215,528 $ 194,315 Weighted average common shares outstanding 100,598 100,198 100,509 100,231 Basic income per common share $ .71 $ .65 $ 2.14 $ 1.94 Diluted income per common share: Net income available to common shareholders $ 72,314 $ 66,295 $ 218,278 $ 197,062 Less income allocated to nonvested restricted stock 860 912 2,743 2,743 Net income allocated to common stock $ 71,454 $ 65,383 $ 215,535 $ 194,319 Weighted average common shares outstanding 100,598 100,198 100,509 100,231 Net effect of the assumed exercise of stock-based awards - based on the treasury stock method using the average market price for the respective periods 336 255 358 248 Weighted average diluted common shares outstanding 100,934 100,453 100,867 100,479 Diluted income per common share $ .71 $ .65 $ 2.14 $ 1.93

Accumulated Other Comprehensi29

Accumulated Other Comprehensive Income (Tables)	9 Months Ended
	Sep. 30, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule Of Accumulated Other Comprehensive Income	The table below shows the activity and accumulated balances for components of other comprehensive income. The largest component is the unrealized holding gains and losses on available for sale securities. Unrealized gains and losses on debt securities for which an other-than-temporary impairment (OTTI) has been recorded in current earnings are shown separately below. The other component is the amortization from other comprehensive income of losses associated with pension benefits, which occurs as the losses are included in current net periodic pension cost. Unrealized Gains (Losses) on Securities (1) Pension Loss (2) Total Accumulated Other Comprehensive Income (In thousands) OTTI Other Balance January 1, 2017 $ 2,975 $ 27,328 $ (19,328 ) $ 10,975 Other comprehensive income before reclassifications 365 94,794 — 95,159 Amounts reclassified from accumulated other comprehensive income 372 (6,731 ) 1,661 (4,698 ) Current period other comprehensive income, before tax 737 88,063 1,661 90,461 Income tax expense (280 ) (33,464 ) (631 ) (34,375 ) Current period other comprehensive income, net of tax 457 54,599 1,030 56,086 Transfer of unrealized gain on securities for which impairment was not previously recognized 24 (24 ) — — Balance September 30, 2017 $ 3,456 $ 81,903 $ (18,298 ) $ 67,061 Balance January 1, 2016 $ 3,316 $ 49,750 $ (20,596 ) $ 32,470 Other comprehensive income (loss) before reclassifications (837 ) 141,752 — 140,915 Amounts reclassified from accumulated other comprehensive income 270 — 1,737 2,007 Current period other comprehensive income (loss), before tax (567 ) 141,752 1,737 142,922 Income tax (expense) benefit 215 (53,865 ) (660 ) (54,310 ) Current period other comprehensive income (loss), net of tax (352 ) 87,887 1,077 88,612 Balance September 30, 2016 $ 2,964 $ 137,637 $ (19,519 ) $ 121,082

Segments (Tables)

Segments (Tables)	9 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Schedule Of Financial Information By Segment	he following table presents selected financial information by segment and reconciliations of combined segment totals to consolidated totals. There were no material intersegment revenues among the three segments. Management periodically makes changes to methods of assigning costs and income to its business segments to better reflect operating results. If appropriate, these changes are reflected in prior year information presented below. (In thousands) Consumer Commercial Wealth Segment Totals Other/Elimination Consolidated Totals Three Months Ended September 30, 2017 Net interest income $ 70,793 $ 82,012 $ 11,744 $ 164,549 $ 18,042 $ 182,591 Provision for loan losses (11,067 ) 335 (10 ) (10,742 ) 38 (10,704 ) Non-interest income 35,194 47,902 40,404 123,500 (1,258 ) 122,242 Investment securities losses, net — — — — (3,037 ) (3,037 ) Non-interest expense (72,607 ) (71,468 ) (30,528 ) (174,603 ) (9,969 ) (184,572 ) Income before income taxes $ 22,313 $ 58,781 $ 21,610 $ 102,704 $ 3,816 $ 106,520 Nine Months Ended September 30, 2017 Net interest income $ 207,421 $ 243,517 $ 35,515 $ 486,453 $ 57,218 $ 543,671 Provision for loan losses (31,531 ) 959 (9 ) (30,581 ) (2,009 ) (32,590 ) Non-interest income 101,211 144,781 116,961 362,953 (561 ) 362,392 Investment securities losses, net — — — — (2,158 ) (2,158 ) Non-interest expense (217,733 ) (219,307 ) (90,323 ) (527,363 ) (28,633 ) (555,996 ) Income before income taxes $ 59,368 $ 169,950 $ 62,144 $ 291,462 $ 23,857 $ 315,319 Three Months Ended September 30, 2016 Net interest income $ 67,375 $ 78,514 $ 10,782 $ 156,671 $ 14,572 $ 171,243 Provision for loan losses (9,033 ) 2,432 (5 ) (6,606 ) (657 ) (7,263 ) Non-interest income 34,230 49,832 36,676 120,738 (1,419 ) 119,319 Investment securities losses, net — — — — (1,965 ) (1,965 ) Non-interest expense (70,134 ) (71,200 ) (28,172 ) (169,506 ) (11,736 ) (181,242 ) Income before income taxes $ 22,438 $ 59,578 $ 19,281 $ 101,297 $ (1,205 ) $ 100,092 Nine Months Ended September 30, 2016 Net interest income $ 201,166 $ 231,780 $ 32,604 $ 465,550 $ 41,297 $ 506,847 Provision for loan losses (26,533 ) 3,919 (120 ) (22,734 ) (3,184 ) (25,918 ) Non-interest income 97,165 149,240 107,696 354,101 812 354,913 Investment securities losses, net — — — — (3,704 ) (3,704 ) Non-interest expense (209,660 ) (211,450 ) (85,116 ) (506,226 ) (29,578 ) (535,804 ) Income before income taxes $ 62,138 $ 173,489 $ 55,064 $ 290,691 $ 5,643 $ 296,334

Derivative Instruments (Tables)

Derivative Instruments (Tables)	9 Months Ended
	Sep. 30, 2017
Derivative Instrument Detail [Abstract]
Schedule Of Notional Amounts Of Derivative Instruments	(In thousands) September 30, 2017 December 31, 2016 Interest rate swaps $ 1,723,448 $ 1,685,099 Interest rate caps 31,923 59,379 Credit risk participation agreements 112,348 121,514 Foreign exchange contracts 8,783 4,046 Mortgage loan commitments 23,616 12,429 Mortgage loan forward sale contracts 1,607 6,626 Forward TBA contracts 32,000 15,000 Total notional amount $ 1,933,725 $ 1,904,093
Schedule Of Fair Values Of Derivative Instruments	The fair values of the Company's derivative instruments, whose notional amounts are listed above, are shown in the table below. Derivative instruments with a positive fair value (asset derivatives) are reported in other assets in the consolidated balance sheets, while derivative instruments with a negative fair value (liability derivatives) are reported in other liabilities in the consolidated balance sheets. Information about the valuation methods used to determine fair value is provided in Note 13 on Fair Value Measurements. Asset Derivatives Liability Derivatives Sept. 30, 2017 Dec. 31, 2016 Sept. 30, 2017 Dec. 31, 2016 (In thousands ) Fair Value Fair Value Derivative instruments: Interest rate swaps $ 10,630 $ 12,987 $ (5,775 ) $ (12,987 ) Interest rate caps 29 78 (29 ) (78 ) Credit risk participation agreements 56 65 (129 ) (156 ) Foreign exchange contracts 68 66 (30 ) (4 ) Mortgage loan commitments 757 355 — (6 ) Mortgage loan forward sale contracts 8 — — (63 ) Forward TBA contracts 102 15 (16 ) (45 ) Total $ 11,650 $ 13,566 $ (5,979 ) $ (13,339 )
Summary Of The Effects Of Derivative Instruments On Consolidated Statements Of Income	The effects of derivative instruments on the consolidated statements of income are shown in the table below. Location of Gain or (Loss) Recognized in Income on Derivatives Amount of Gain or (Loss) Recognized in Income on Derivatives For the Three Months Ended September 30 For the Nine Months Ended September 30 (In thousands) 2017 2016 2017 2016 Derivative instruments: Interest rate swaps Other non-interest income $ 702 $ 203 $ 1,301 $ 3,198 Credit risk participation agreements Other non-interest income 7 50 18 (8 ) Foreign exchange contracts Other non-interest income 51 (20 ) (24 ) (12 ) Mortgage loan commitments Loan fees and sales (114 ) 86 408 613 Mortgage loan forward sale contracts Loan fees and sales 8 1 70 1 Forward TBA contracts Loan fees and sales (322 ) (172 ) (580 ) (898 ) Total $ 332 $ 148 $ 1,193 $ 2,894
Balance Sheet Offsetting, Derivatives [Table Text Block]	Gross Amounts Not Offset in the Balance Sheet (In thousands) Gross Amount Recognized Gross Amounts Offset in the Balance Sheet Net Amounts Presented in the Balance Sheet Financial Instruments Available for Offset Collateral Received/Pledged Net Amount September 30, 2017 Assets: Derivatives subject to master netting agreements $ 10,809 $ — $ 10,809 $ (364 ) $ — $ 10,445 Derivatives not subject to master netting agreements 841 — 841 Total derivatives 11,650 — 11,650 Liabilities: Derivatives subject to master netting agreements $ 5,829 $ — $ 5,829 $ (364 ) $ (1,692 ) $ 3,773 Derivatives not subject to master netting agreements 150 — 150 Total derivatives 5,979 — 5,979 December 31, 2016 Assets: Derivatives subject to master netting agreements $ 13,111 $ — $ 13,111 $ (3,391 ) $ — $ 9,720 Derivatives not subject to master netting agreements 455 — 455 Total derivatives 13,566 — 13,566 Liabilities: Derivatives subject to master netting agreements $ 13,124 $ — $ 13,124 $ (3,391 ) $ (5,292 ) $ 4,441 Derivatives not subject to master netting agreements 215 — 215 Total derivatives 13,339 — 13,339

Resale and Repurchase Agreeme32

Resale and Repurchase Agreements (Tables)	9 Months Ended
	Sep. 30, 2017
Resale and Repurchase Agreements [Abstract]
Resale and Repurchase Agreements [Table Text Block]	Gross Amounts Not Offset in the Balance Sheet (In thousands) Gross Amount Recognized Gross Amounts Offset in the Balance Sheet Net Amounts Presented in the Balance Sheet Financial Instruments Available for Offset Securities Collateral Received/Pledged Net Amount September 30, 2017 Total resale agreements, subject to master netting arrangements $ 1,350,000 $ (650,000 ) $ 700,000 $ — $ (700,000 ) $ — Total repurchase agreements, subject to master netting arrangements 1,708,074 (650,000 ) 1,058,074 — (1,058,074 ) — December 31, 2016 Total resale agreements, subject to master netting arrangements $ 1,275,000 $ (550,000 ) $ 725,000 $ — $ (725,000 ) $ — Total repurchase agreements, subject to master netting arrangements 2,221,065 (550,000 ) 1,671,065 — (1,671,065 ) —
Schedule of Underlying Assets of Repurchase Agreements [Table Text Block]	Remaining Contractual Maturity of the Agreements (In thousands) Overnight and continuous Up to 90 days Greater than 90 days Total September 30, 2017 Repurchase agreements, secured by: U.S. government and federal agency obligations $ 326,080 $ — $ 450,000 $ 776,080 Government-sponsored enterprise obligations 186,896 — — 186,896 Agency mortgage-backed securities 317,780 19,730 200,000 537,510 Asset-backed securities 117,588 90,000 — 207,588 Total repurchase agreements, gross amount recognized $ 948,344 $ 109,730 $ 650,000 $ 1,708,074 December 31, 2016 Repurchase agreements, secured by: U.S. government and federal agency obligations $ 294,600 $ — $ 300,000 $ 594,600 Government-sponsored enterprise obligations 147,694 — 3,237 150,931 Agency mortgage-backed securities 693,851 24,380 252,473 970,704 Asset-backed securities 474,830 30,000 — 504,830 Total repurchase agreements, gross amount recognized $ 1,610,975 $ 54,380 $ 555,710 $ 2,221,065

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2017
Share-based Compensation [Abstract]
Summary Of The Status Of Nonvested Share Awards	A summary of the status of the Company’s nonvested share awards as of September 30, 2017 , and changes during the nine month period then ended, is presented below. Shares Weighted Average Grant Date Fair Value Nonvested at January 1, 2017 1,392,451 $34.67 Granted 242,244 57.31 Vested (403,586 ) 30.87 Forfeited (20,250 ) 40.72 Nonvested at September 30, 2017 1,210,859 $40.36
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	The current year per share average fair value and the model assumptions are shown in the table below. Weighted per share average fair value at grant date $12.54 Assumptions: Dividend yield 1.6 % Volatility 21.1 % Risk-free interest rate 2.4 % Expected term 7.0 years
Summary Of SAR Activity	A summary of SAR activity during the first nine months of 2017 is presented below. (Dollars in thousands, except per share data) Rights Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value Outstanding at January 1, 2017 1,324,954 $34.53 Granted 165,592 57.53 Forfeited (9,448 ) 44.25 Expired (837 ) 36.48 Exercised (317,621 ) 30.86 Outstanding at September 30, 2017 1,162,640 $38.73 6.3 years $ 21,821

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2017
Fair Value Measurements [Abstract]
Summary Of Assets And Liabilities Measured At Fair Value On A Recurring Basis	The table below presents the September 30, 2017 and December 31, 2016 carrying values of assets and liabilities measured at fair value on a recurring basis. There were no transfers among levels during the first nine months of 2017 or the year ended December 31, 2016 . Fair Value Measurements Using (In thousands) Total Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) September 30, 2017 Assets: Residential mortgage loans held for sale $ 11,320 $ — $ 11,320 $ — Available for sale securities: U.S. government and federal agency obligations 918,604 918,604 — — Government-sponsored enterprise obligations 469,414 — 469,414 — State and municipal obligations 1,720,403 — 1,703,550 16,853 Agency mortgage-backed securities 2,756,973 — 2,756,973 — Non-agency mortgage-backed securities 1,066,764 — 1,066,764 — Asset-backed securities 1,736,966 — 1,736,966 — Other debt securities 356,641 — 356,641 — Equity securities 83,522 32,915 50,607 — Trading securities 24,605 — 24,605 — Private equity investments 50,254 — — 50,254 Derivatives * 11,650 — 10,837 813 Assets held in trust for deferred compensation plan 12,311 12,311 — — Total assets 9,219,427 963,830 8,187,677 67,920 Liabilities: Derivatives * 5,979 — 5,850 129 Liabilities held in trust for deferred compensation plan 12,311 12,311 — — Total liabilities $ 18,290 $ 12,311 $ 5,850 $ 129 December 31, 2016 Assets: Residential mortgage loans held for sale $ 9,263 $ — $ 9,263 $ — Available for sale securities: U.S. government and federal agency obligations 920,904 920,904 — — Government-sponsored enterprise obligations 449,998 — 449,998 — State and municipal obligations 1,778,214 — 1,761,532 16,682 Agency mortgage-backed securities 2,685,931 — 2,685,931 — Non-agency mortgage-backed securities 1,055,639 — 1,055,639 — Asset-backed securities 2,381,301 — 2,381,301 — Other debt securities 325,953 — 325,953 — Equity securities 51,263 24,967 26,296 — Trading securities 22,225 — 22,225 — Private equity investments 50,820 — — 50,820 Derivatives * 13,566 — 13,146 420 Assets held in trust for deferred compensation plan 10,261 10,261 — — Total assets 9,755,338 956,132 8,731,284 67,922 Liabilities: Derivatives * 13,339 — 13,177 162 Liabilities held in trust for deferred compensation plan 10,261 10,261 — — Total liabilities $ 23,600 $ 10,261 $ 13,177 $ 162
Summary Of Changes In Level 3 Assets And Liabilities Measured At Fair Value On A Recurring Basis	The changes in Level 3 assets and liabilities measured at fair value on a recurring basis are summarized as follows: Fair Value Measurements Using Significant Unobservable Inputs (Level 3) (In thousands) State and Municipal Obligations Private Equity Investments Derivatives Total For the three months ended September 30, 2017 Balance June 30, 2017 $ 16,825 $ 53,557 $ 791 $ 71,173 Total gains or losses (realized/unrealized): Included in earnings — (5,198 ) (107 ) (5,305 ) Included in other comprehensive income * 19 — — 19 Discount accretion 9 — — 9 Purchases of private equity investments — 2,185 — 2,185 Sale/pay down of private equity investments — (290 ) — (290 ) Balance September 30, 2017 $ 16,853 $ 50,254 $ 684 $ 67,791 Total gains or losses for the three months included in earnings attributable to the change in unrealized gains or losses relating to assets still held at September 30, 2017 $ — $ (5,198 ) $ 764 $ (4,434 ) For the nine months ended September 30, 2017 Balance January 1, 2017 $ 16,682 $ 50,820 $ 258 $ 67,760 Total gains or losses (realized/unrealized): Included in earnings — (8,028 ) 426 (7,602 ) Included in other comprehensive income * 729 — — 729 Investment securities called (600 ) — — (600 ) Discount accretion 42 — — 42 Purchases of private equity investments — 9,269 — 9,269 Sale/pay down of private equity investments — (1,840 ) — (1,840 ) Capitalized interest/dividends — 33 — 33 Balance September 30, 2017 $ 16,853 $ 50,254 $ 684 $ 67,791 Total gains or losses for the nine months included in earnings attributable to the change in unrealized gains or losses relating to assets still held at September 30, 2017 $ — $ (7,853 ) $ 775 $ (7,078 ) For the three months ended September 30, 2016 Balance June 30, 2016 $ 17,679 $ 62,813 $ 502 $ 80,994 Total gains or losses (realized/unrealized): Included in earnings — (2,921 ) 136 (2,785 ) Included in other comprehensive income * 317 — — 317 Investment securities called (1,100 ) — — (1,100 ) Discount accretion 12 — — 12 Purchases of private equity investments — 2,894 — 2,894 Sale/pay down of private equity investments — (3,315 ) — (3,315 ) Capitalized interest/dividends — 15 — 15 Sale of risk participation agreement — — (33 ) (33 ) Balance September 30, 2016 $ 16,908 $ 59,486 $ 605 $ 76,999 Total gains or losses for the three months included in earnings attributable to the change in unrealized gains or losses relating to assets still held at September 30, 2016 $ — $ (2,921 ) $ 926 $ (1,995 ) For the nine months ended September 30, 2016 Balance January 1, 2016 $ 17,195 $ 63,032 $ 69 $ 80,296 Total gains or losses (realized/unrealized): Included in earnings — (6,645 ) 605 (6,040 ) Included in other comprehensive income * 819 — — 819 Investment securities called (1,200 ) — — (1,200 ) Discount accretion 94 — — 94 Purchases of private equity investments — 8,735 — 8,735 Sale/pay down of private equity investments — (5,713 ) — (5,713 ) Capitalized interest/dividends — 77 — 77 Sale of risk participation agreement — — (69 ) (69 ) Balance September 30, 2016 $ 16,908 $ 59,486 $ 605 $ 76,999 Total gains or losses for the nine months included in earnings attributable to the change in unrealized gains or losses relating to assets still held at September 30, 2016 $ — $ (6,545 ) $ 868 $ (5,677 )
Summary Of Gains And Losses On Level 3 Assets And Liabilities	Gains and losses included in earnings for the Level 3 assets and liabilities in the previous table are reported in the following line items in the consolidated statements of income: (In thousands) Loan Fees and Sales Other Non-Interest Income Investment Securities Gains (Losses), Net Total For the three months ended September 30, 2017 Total gains or losses included in earnings $ (115 ) $ 8 $ (5,198 ) $ (5,305 ) Change in unrealized gains or losses relating to assets still held at September 30, 2017 $ 756 $ 8 $ (5,198 ) $ (4,434 ) For the nine months ended September 30, 2017 Total gains or losses included in earnings $ 407 $ 19 $ (8,028 ) $ (7,602 ) Change in unrealized gains or losses relating to assets still held at September 30, 2017 $ 756 $ 19 $ (7,853 ) $ (7,078 ) For the three months ended September 30, 2016 Total gains or losses included in earnings $ 86 $ 50 $ (2,921 ) $ (2,785 ) Change in unrealized gains or losses relating to assets still held at September 30, 2016 $ 876 $ 50 $ (2,921 ) $ (1,995 ) For the nine months ended September 30, 2016 Total gains or losses included in earnings $ 613 $ (8 ) $ (6,645 ) $ (6,040 ) Change in unrealized gains or losses relating to assets still held at September 30, 2016 $ 876 $ (8 ) $ (6,545 ) $ (5,677 )
Summary Of Quantitative Information About Level 3 Fair Value Measurements	s The Company's significant Level 3 measurements which employ unobservable inputs that are readily quantifiable pertain to auction rate securities (ARS) held by the Bank, investments in portfolio concerns held by the Company's private equity subsidiaries, and held for sale residential mortgage loan commitments. ARS are included in state and municipal securities and totaled $16.9 million at September 30, 2017 , while private equity investments, included in non-marketable securities, totaled $50.3 million . Information about these inputs is presented in the table and discussions below. Quantitative Information about Level 3 Fair Value Measurements Weighted Valuation Technique Unobservable Input Range Average Auction rate securities Discounted cash flow Estimated market recovery period 5 years Estimated market rate 2.8% - 3.1% Private equity investments Market comparable companies EBITDA multiple 4.0 - 5.8 Mortgage loan commitments Discounted cash flow Probability of funding 50.9% - 100.0% 79.1% Embedded servicing value (.3)% - 2.2% 1.1%
Schedule Of Fair Value Disclosures Measured On Nonrecurring Basis [Table Text Block]	s For assets measured at fair value on a nonrecurring basis during the first nine months of 2017 and 2016 , and still held as of September 30, 2017 and 2016 , the following table provides the adjustments to fair value recognized during the respective periods, the level of valuation inputs used to determine each adjustment, and the carrying value of the related individual assets or portfolios at September 30, 2017 and 2016 . Fair Value Measurements Using (In thousands) Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Gains (Losses) Recognized During the Nine Months Ended September 30 September 30, 2017 Collateral dependent impaired loans $ 1,468 $ — $ — $ 1,468 $ (336 ) Mortgage servicing rights 4,245 — — 4,245 6 Foreclosed assets 50 — — 50 (83 ) Long-lived assets 3,033 — — 3,033 (1,167 ) September 30, 2016 Collateral dependent impaired loans $ 1,756 $ — $ — $ 1,756 $ (1,626 ) Mortgage servicing rights 2,533 — — 2,533 (7 ) Foreclosed assets 47 — — 47 (66 ) Long-lived assets 2,232 — — 2,232 (1,001 )

Fair Value Of Financial Instr35

Fair Value Of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2017
Fair Value Of Financial Instruments [Abstract]
Fair value of financial instruments [Table Text Block]	Fair Value Hierarchy Level September 30, 2017 December 31, 2016 (In thousands) Carrying Amount Estimated Fair Value Carrying Amount Estimated Fair Value Financial Assets Loans: Business Level 3 $ 4,834,037 $ 4,848,169 $ 4,776,365 $ 4,787,469 Real estate - construction and land Level 3 921,609 933,862 791,236 800,426 Real estate - business Level 3 2,700,174 2,712,002 2,643,374 2,658,093 Real estate - personal Level 3 2,029,302 2,034,374 2,010,397 2,005,227 Consumer Level 3 2,113,438 2,088,302 1,990,801 1,974,784 Revolving home equity Level 3 391,308 391,419 413,634 414,499 Consumer credit card Level 3 752,379 767,344 776,465 794,856 Overdrafts Level 3 3,245 3,245 10,464 10,464 Loans held for sale Level 2 17,337 17,337 14,456 14,456 Investment securities: Available for sale Level 1 951,519 951,519 945,871 945,871 Available for sale Level 2 8,140,915 8,140,915 8,686,650 8,686,650 Available for sale Level 3 16,853 16,853 16,682 16,682 Trading Level 2 24,605 24,605 22,225 22,225 Non-marketable Level 3 99,268 99,268 99,558 99,558 Federal funds sold Level 1 32,630 32,630 15,470 15,470 Securities purchased under agreements to resell Level 3 700,000 702,989 725,000 728,179 Interest earning deposits with banks Level 1 105,422 105,422 272,275 272,275 Cash and due from banks Level 1 461,724 461,724 494,690 494,690 Derivative instruments Level 2 10,837 10,837 13,146 13,146 Derivative instruments Level 3 813 813 420 420 Assets held in trust for deferred compensation plan Level 1 12,311 12,311 10,261 10,261 Financial Liabilities Non-interest bearing deposits Level 1 $ 7,536,127 $ 7,536,127 $ 7,429,398 $ 7,429,398 Savings, interest checking and money market deposits Level 1 11,091,200 11,091,200 11,430,789 11,430,789 Time open and certificates of deposit Level 3 1,816,446 1,820,178 2,240,908 2,235,218 Federal funds purchased Level 1 350,910 350,910 52,840 52,840 Securities sold under agreements to repurchase Level 3 1,058,074 1,058,459 1,671,065 1,671,227 Other borrowings Level 3 102,553 103,012 102,049 104,298 Derivative instruments Level 2 5,850 5,850 13,177 13,177 Derivative instruments Level 3 129 129 162 162 Liabilities held in trust for deferred compensation plan Level 1 12,311 12,311 10,261 10,261

Loans And Allowance For Loan 36

Loans And Allowance For Loan Losses (Narrative) (Details) - USD ($)	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Loans And Allowance For Loan Losses [Abstract]
Loans pledged at the Federal Home Loan Bank as collateral for borrowings and letters of credit obtained to secure public deposits	$ 3,800,000,000
Loans Pledged to the Federal Reserve Bank as collateral for discount window borrowings	1,700,000,000
Troubled Debt Restructured Loans	73,100,000
Accruing Restructured Loans	65,900,000	$ 50,249,000
Restructured Loans NonAccrual	7,200,000
Restructured commercial loans performing under their modified terms	51,000,000
Aggregate restructured credit card loans held	7,000,000
Restructured Loans Due to Bankruptcy Proceeding	$ 7,700,000
Period after which loans are deemed in default (in days)	90 days
Effect on Interest Income Resulting From Modification to Credit Card Loans	$ (979,000)
Commitments to lend additional funds to customers with restructured loans	10,600,000
Fair Value of Personal Real Estate Loans Held for Sale	11,300,000
Unpaid Principal Balance on Personal Real Estate Loans Held for Sale	10,900,000
Student Loans Held for Sale, Lower of Cost or Fair Value	6,000,000
Non-accrual HFS loans	0
Loans HFS 90 Days Past Due and Still Accruing	0
Foreclosed real estate	1,100,000	366,000
Personal property acquired in repossession	$ 2,700,000	$ 2,200,000

Loans And Allowance For Loan 37

Loans And Allowance For Loan Losses (Summary Classification Of Held To Maturity Loan Portfolio) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Loans And Allowance For Loan Losses [Line Items]
Total loans	$ 13,745,492	$ 13,412,736
Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Total loans	4,834,037	4,776,365
Real Estate - Construction And Land [Member]
Loans And Allowance For Loan Losses [Line Items]
Total loans	921,609	791,236
Real Estate - Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Total loans	2,700,174	2,643,374
Real Estate - Personal [Member]
Loans And Allowance For Loan Losses [Line Items]
Total loans	2,029,302	2,010,397
Consumer [Member]
Loans And Allowance For Loan Losses [Line Items]
Total loans	2,113,438	1,990,801
Revolving Home Equity [Member]
Loans And Allowance For Loan Losses [Line Items]
Total loans	391,308	413,634
Consumer Credit Card [Member]
Loans And Allowance For Loan Losses [Line Items]
Total loans	752,379	776,465
Overdrafts [Member]
Loans And Allowance For Loan Losses [Line Items]
Total loans	$ 3,245	$ 10,464

Loans And Allowance For Loan 38

Loans And Allowance For Loan Losses (Summary Of Activity In The Allowance For Loan Losses) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	$ 157,832	$ 153,832	$ 155,932	$ 151,532
Provision	10,704	7,263	32,590	25,918
Loans charged off	13,970	12,163	40,792	38,098
Less recoveries on loans	3,266	5,600	10,102	15,180
Net loan charge-offs (recoveries)	10,704	6,563	30,690	22,918
Balance at end of period	157,832	154,532	157,832	154,532
Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	92,739	89,198	91,361	82,086
Provision	24	(1,411)	1,026	4,309
Loans charged off	378	291	1,455	2,465
Less recoveries on loans	651	2,759	2,104	6,325
Net loan charge-offs (recoveries)	(273)	(2,468)	(649)	(3,860)
Balance at end of period	93,036	90,255	93,036	90,255
Personal Banking Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	65,093	64,634	64,571	69,446
Provision	10,680	8,674	31,564	21,609
Loans charged off	13,592	11,872	39,337	35,633
Less recoveries on loans	2,615	2,841	7,998	8,855
Net loan charge-offs (recoveries)	10,977	9,031	31,339	26,778
Balance at end of period	$ 64,796	$ 64,277	$ 64,796	$ 64,277

Loans And Allowance For Loan 39

Loans And Allowance For Loan Losses (Allowance For Loan Losses And Related Loan Balance Disaggregated On The Basis Of Impairment Methodology) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Loans And Allowance For Loan Losses [Line Items]
Loans And Leases Receivable Excluding Impaired Financing Receivables Recorded Investment	$ 13,665,952	$ 13,348,204
Impaired Financing Receivable, Recorded Investment	79,540	64,532
Loans and Leases Receivable Allowance Excluding Impaired Financing Receivable Related Allowance	154,721	152,823
Impaired Financing Receivable, Related Allowance	3,111	3,109
Commercial Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans And Leases Receivable Excluding Impaired Financing Receivables Recorded Investment	8,399,851	8,166,180
Impaired Financing Receivable, Recorded Investment	55,969	44,795
Loans and Leases Receivable Allowance Excluding Impaired Financing Receivable Related Allowance	91,247	89,544
Impaired Financing Receivable, Related Allowance	1,789	1,817
Personal Banking Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans And Leases Receivable Excluding Impaired Financing Receivables Recorded Investment	5,266,101	5,182,024
Impaired Financing Receivable, Recorded Investment	23,571	19,737
Loans and Leases Receivable Allowance Excluding Impaired Financing Receivable Related Allowance	63,474	63,279
Impaired Financing Receivable, Related Allowance	$ 1,322	$ 1,292

Loans And Allowance For Loan 40

Loans And Allowance For Loan Losses (Investment In Impaired Loans) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Loans And Allowance For Loan Losses [Abstract]
Non-accrual loans	$ 13,640	$ 14,283
Restructured loans (accruing)	65,900	50,249
Total impaired loans	$ 79,540	$ 64,532

Loans And Allowance For Loan 41

Loans And Allowance For Loan Losses (Additional Information About Impaired Loans Held) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Loans And Allowance For Loan Losses [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	$ 7,806	$ 7,932
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	11,359	11,222
Impaired Financing Receivable, with Related Allowance, Recorded Investment	71,734	56,600
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	76,534	62,481
Impaired Financing Receivable, Related Allowance	3,111	3,109
Impaired Financing Receivable, Recorded Investment	79,540	64,532
Impaired Financing Receivable, Unpaid Principal Balance	87,893	73,703
Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	6,196	7,375
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	9,725	10,470
Impaired Financing Receivable, with No Related Allowance, Allowance	0	0
Impaired Financing Receivable, with Related Allowance, Recorded Investment	35,708	29,924
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	36,219	31,795
Impaired Financing Receivable, Related Allowance	1,141	1,318
Real Estate - Construction And Land [Member]
Loans And Allowance For Loan Losses [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	0	557
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	0	752
Impaired Financing Receivable, with No Related Allowance, Allowance	0	0
Impaired Financing Receivable, with Related Allowance, Recorded Investment	1,367	69
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	1,595	72
Impaired Financing Receivable, Related Allowance	37	3
Real Estate - Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	587	0
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	587	0
Impaired Financing Receivable, with No Related Allowance, Allowance	0	0
Impaired Financing Receivable, with Related Allowance, Recorded Investment	12,111	6,870
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	13,319	8,072
Impaired Financing Receivable, Related Allowance	611	496
Real Estate - Personal [Member]
Loans And Allowance For Loan Losses [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	9,723	6,394
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	12,537	9,199
Impaired Financing Receivable, Related Allowance	607	642
Consumer [Member]
Loans And Allowance For Loan Losses [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	1,023	0
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	1,047	0
Impaired Financing Receivable, with No Related Allowance, Allowance	0	0
Impaired Financing Receivable, with Related Allowance, Recorded Investment	5,232	5,281
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	5,271	5,281
Impaired Financing Receivable, Related Allowance	52	57
Revolving Home Equity [Member]
Loans And Allowance For Loan Losses [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	578	584
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	578	584
Impaired Financing Receivable, Related Allowance	5	1
Consumer Credit Card [Member]
Loans And Allowance For Loan Losses [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	7,015	7,478
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	7,015	7,478
Impaired Financing Receivable, Related Allowance	$ 658	$ 592

Loans And Allowance For Loan 42

Loans And Allowance For Loan Losses (Total Average Impaired Loans) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Loans And Allowance For Loan Losses [Line Items]
Non-accrual loans	$ 13,176	$ 19,034	$ 13,898	$ 23,723
Restructured loans (accruing)	61,621	48,454	53,468	46,476
Total	74,797	67,488	67,366	70,199
Commercial Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Non-accrual loans	8,938	15,106	9,800	19,387
Restructured loans (accruing)	42,930	31,372	36,567	29,117
Total	51,868	46,478	46,367	48,504
Personal Banking Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Non-accrual loans	4,238	3,928	4,098	4,336
Restructured loans (accruing)	18,691	17,082	16,901	17,359
Total	$ 22,929	$ 21,010	$ 20,999	$ 21,695

Loans And Allowance For Loan 43

Loans And Allowance For Loan Losses (Interest Income Recognized on Impaired Loans) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Loans And Allowance For Loan Losses [Line Items]
Interest income recognized	$ 953	$ 630	$ 2,855	$ 1,892
Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Interest income recognized	473	277	1,418	830
Real Estate - Construction And Land [Member]
Loans And Allowance For Loan Losses [Line Items]
Interest income recognized	10	2	30	7
Real Estate - Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Interest income recognized	118	42	354	126
Real Estate - Personal [Member]
Loans And Allowance For Loan Losses [Line Items]
Interest income recognized	104	39	311	118
Consumer [Member]
Loans And Allowance For Loan Losses [Line Items]
Interest income recognized	79	89	236	267
Revolving Home Equity [Member]
Loans And Allowance For Loan Losses [Line Items]
Interest income recognized	7	7	20	22
Consumer Credit Card [Member]
Loans And Allowance For Loan Losses [Line Items]
Interest income recognized	$ 162	$ 174	$ 486	$ 522

Loans And Allowance For Loan 44

Loans And Allowance For Loan Losses (Aging Information On Past Due And Accruing Loans) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	$ 13,650,861	$ 13,324,515
30 - 89 Days Past Due	64,527	57,542
90 Days Past Due and Still Accruing	16,464	16,396
Non-accrual loans	13,640	14,283
Total	13,745,492	13,412,736
Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	4,834,037	4,776,365
Business [Member] | Commercial Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	4,823,779	4,763,274
30 - 89 Days Past Due	2,630	3,735
90 Days Past Due and Still Accruing	807	674
Non-accrual loans	6,821	8,682
Total	4,834,037	4,776,365
Real Estate - Construction And Land [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	921,609	791,236
Real Estate - Construction And Land [Member] | Commercial Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	917,128	789,633
30 - 89 Days Past Due	3,913	1,039
90 Days Past Due and Still Accruing	35	0
Non-accrual loans	533	564
Total	921,609	791,236
Real Estate - Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	2,700,174	2,643,374
Real Estate - Business [Member] | Commercial Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	2,688,625	2,639,586
30 - 89 Days Past Due	8,580	2,154
90 Days Past Due and Still Accruing	623	0
Non-accrual loans	2,346	1,634
Total	2,700,174	2,643,374
Real Estate - Personal [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	2,029,302	2,010,397
Real Estate - Personal [Member] | Personal Banking Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	2,013,632	1,995,724
30 - 89 Days Past Due	11,141	9,162
90 Days Past Due and Still Accruing	1,666	2,108
Non-accrual loans	2,863	3,403
Total	2,029,302	2,010,397
Consumer [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	2,113,438	1,990,801
Consumer [Member] | Personal Banking Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	2,082,203	1,957,358
30 - 89 Days Past Due	27,450	29,783
90 Days Past Due and Still Accruing	2,708	3,660
Non-accrual loans	1,077	0
Total	2,113,438	1,990,801
Revolving Home Equity [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	391,308	413,634
Revolving Home Equity [Member] | Personal Banking Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	388,346	411,483
30 - 89 Days Past Due	1,530	1,032
90 Days Past Due and Still Accruing	1,432	1,119
Non-accrual loans	0	0
Total	391,308	413,634
Consumer Credit Card [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	752,379	776,465
Consumer Credit Card [Member] | Personal Banking Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	734,215	757,443
30 - 89 Days Past Due	8,971	10,187
90 Days Past Due and Still Accruing	9,193	8,835
Non-accrual loans	0	0
Total	752,379	776,465
Overdrafts [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	3,245	10,464
Overdrafts [Member] | Personal Banking Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less than 30 Days Past Due	2,933	10,014
30 - 89 Days Past Due	312	450
90 Days Past Due and Still Accruing	0	0
Non-accrual loans	0	0
Total	$ 3,245	$ 10,464

Loans And Allowance For Loan 45

Loans And Allowance For Loan Losses (Credit Quality Of Commercial Loan Portfolio) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Loans And Allowance For Loan Losses [Line Items]
Loans	$ 13,745,492	$ 13,412,736
Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans	4,834,037	4,776,365
Real Estate - Construction And Land [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans	921,609	791,236
Real Estate - Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans	2,700,174	2,643,374
Commercial Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans	8,455,820	8,210,975
Commercial Portfolio Segment [Member] | Pass [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans	8,095,586	7,939,679
Commercial Portfolio Segment [Member] | Special Mention [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans	183,395	162,843
Commercial Portfolio Segment [Member] | Substandard [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans	167,139	97,573
Commercial Portfolio Segment [Member] | Non-Accrual [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans	9,700	10,880
Commercial Portfolio Segment [Member] | Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans	4,834,037	4,776,365
Commercial Portfolio Segment [Member] | Business [Member] | Pass [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans	4,593,958	4,607,553
Commercial Portfolio Segment [Member] | Business [Member] | Special Mention [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans	123,549	116,642
Commercial Portfolio Segment [Member] | Business [Member] | Substandard [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans	109,709	43,488
Commercial Portfolio Segment [Member] | Business [Member] | Non-Accrual [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans	6,821	8,682
Commercial Portfolio Segment [Member] | Real Estate - Construction And Land [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans	921,609	791,236
Commercial Portfolio Segment [Member] | Real Estate - Construction And Land [Member] | Pass [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans	915,279	788,778
Commercial Portfolio Segment [Member] | Real Estate - Construction And Land [Member] | Special Mention [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans	2,527	722
Commercial Portfolio Segment [Member] | Real Estate - Construction And Land [Member] | Substandard [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans	3,270	1,172
Commercial Portfolio Segment [Member] | Real Estate - Construction And Land [Member] | Non-Accrual [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans	533	564
Commercial Portfolio Segment [Member] | Real Estate - Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans	2,700,174	2,643,374
Commercial Portfolio Segment [Member] | Real Estate - Business [Member] | Pass [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans	2,586,349	2,543,348
Commercial Portfolio Segment [Member] | Real Estate - Business [Member] | Special Mention [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans	57,319	45,479
Commercial Portfolio Segment [Member] | Real Estate - Business [Member] | Substandard [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans	54,160	52,913
Commercial Portfolio Segment [Member] | Real Estate - Business [Member] | Non-Accrual [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans	$ 2,346	$ 1,634

Loans And Allowance For Loan 46

Loans And Allowance For Loan Losses (Summary Of Loans In The Personal Banking Portfolio Percentage Of Balances Outstanding ) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Loans And Allowance For Loan Losses [Line Items]
Credit Quality Personal Real Estate Loans Excluded	$ 220.7	$ 237.2
Credit quality personal banking loan table percentage loans excluded	4.20%
Real Estate - Personal [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	100.00%	100.00%
Real Estate - Personal [Member] | Fico Under Six Hundred [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	1.40%	1.30%
Real Estate - Personal [Member] | Fico Six Hundred To Six Hundred Fifty Nine [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	2.20%	2.60%
Real Estate - Personal [Member] | Fico Six Hundred Sixty To Seven Hundred Nineteen [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	10.10%	10.40%
Real Estate - Personal [Member] | Fico Seven Hundred Twenty To Seven Hundred Seventy Nine [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	24.80%	25.40%
Real Estate - Personal [Member] | Fico Seven Hundred Eighty And Above [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	61.50%	60.30%
Consumer [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	100.00%	100.00%
Consumer [Member] | Fico Under Six Hundred [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	3.30%	3.40%
Consumer [Member] | Fico Six Hundred To Six Hundred Fifty Nine [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	5.70%	6.40%
Consumer [Member] | Fico Six Hundred Sixty To Seven Hundred Nineteen [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	17.10%	19.70%
Consumer [Member] | Fico Seven Hundred Twenty To Seven Hundred Seventy Nine [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	26.10%	26.30%
Consumer [Member] | Fico Seven Hundred Eighty And Above [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	47.80%	44.20%
Revolving Home Equity [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	100.00%	100.00%
Revolving Home Equity [Member] | Fico Under Six Hundred [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	0.90%	1.00%
Revolving Home Equity [Member] | Fico Six Hundred To Six Hundred Fifty Nine [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	2.10%	1.80%
Revolving Home Equity [Member] | Fico Six Hundred Sixty To Seven Hundred Nineteen [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	9.00%	9.70%
Revolving Home Equity [Member] | Fico Seven Hundred Twenty To Seven Hundred Seventy Nine [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	21.20%	21.10%
Revolving Home Equity [Member] | Fico Seven Hundred Eighty And Above [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	66.80%	66.40%
Consumer Credit Card [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	100.00%	100.00%
Consumer Credit Card [Member] | Fico Under Six Hundred [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	5.00%	4.90%
Consumer Credit Card [Member] | Fico Six Hundred To Six Hundred Fifty Nine [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	15.10%	15.50%
Consumer Credit Card [Member] | Fico Six Hundred Sixty To Seven Hundred Nineteen [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	34.90%	34.90%
Consumer Credit Card [Member] | Fico Seven Hundred Twenty To Seven Hundred Seventy Nine [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	25.90%	25.10%
Consumer Credit Card [Member] | Fico Seven Hundred Eighty And Above [Member]
Loans And Allowance For Loan Losses [Line Items]
Percentage of Loan Category	19.10%	19.60%

Loans And Allowance For Loan 47

Loans And Allowance For Loan Losses (Outstanding Balance Of Loans Classified As Troubled Debt Restructurings) (Details) $ in Thousands	Sep. 30, 2017USD ($)
Loans And Allowance For Loan Losses [Line Items]
Restructured loans	$ 73,089
Balance 90 days past due at any time during previous 12 months	1,894
Commercial Portfolio Segment [Member] | Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Restructured loans	40,608
Balance 90 days past due at any time during previous 12 months	0
Commercial Portfolio Segment [Member] | Real Estate - Construction And Land [Member]
Loans And Allowance For Loan Losses [Line Items]
Restructured loans	1,304
Balance 90 days past due at any time during previous 12 months	0
Commercial Portfolio Segment [Member] | Real Estate - Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Restructured loans	10,353
Balance 90 days past due at any time during previous 12 months	623
Personal Banking Portfolio Segment [Member] | Real Estate - Personal [Member]
Loans And Allowance For Loan Losses [Line Items]
Restructured loans	7,996
Balance 90 days past due at any time during previous 12 months	397
Personal Banking Portfolio Segment [Member] | Consumer [Member]
Loans And Allowance For Loan Losses [Line Items]
Restructured loans	5,235
Balance 90 days past due at any time during previous 12 months	32
Personal Banking Portfolio Segment [Member] | Revolving Home Equity [Member]
Loans And Allowance For Loan Losses [Line Items]
Restructured loans	578
Balance 90 days past due at any time during previous 12 months	42
Personal Banking Portfolio Segment [Member] | Consumer Credit Card [Member]
Loans And Allowance For Loan Losses [Line Items]
Restructured loans	7,015
Balance 90 days past due at any time during previous 12 months	$ 800

Investment Securities (Narrativ

Investment Securities (Narrative) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Dec. 31, 2015USD ($)
Investment [Line Items]
Non-marketable FHLB and FRB stock held for debt and regulatory purposes	$ 47,300	$ 46,900
Non-marketable private equity investments held	51,700	52,300
U.S. Treasury inflation-protected securities held, at fair value	$ 438,700
Percentage decrease requiring a review for impairment	20.00%
Fair value of securities on other-than-temporary impairment watch list	$ 63,600	79,600
Credit-related portion of impairments included in earnings, for securities on watch list	14,245	14,080	$ 14,228	$ 14,129
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	28,352	60,942
Available for sale securities	9,109,287	9,649,203
Securities pledged as collateral	3,700,000
Securities pledged as collateral and may be sold or re-pledged	$ 667,200
Number of investments in a single issuer that exceed 10% of stockholder's equity	0
No investment in a single issuer exceeds this percentage of stockholder's equity	10.00%
State And Municipal Obligations [Member]
Investment [Line Items]
Auction rate securities held at fair value	$ 16,900
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	1,685	12,693
Unrealized Losses on Auction Rate Securities	221
Available for sale securities	$ 1,720,403	1,778,214
State and municipal obligation portfolio, excluding auction rate securities, as a percentage of total available for sale securities	18.90%
Equity Securities [Member]
Investment [Line Items]
Common stock held by the holding company	$ 83,400
Available for sale securities	83,522	51,263
Non-Agency Mortgage-Backed Securities [Member]
Investment [Line Items]
Fair value of securities on other-than-temporary impairment watch list	28,100
Credit-related portion of impairments included in earnings, for securities on watch list	14,200
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	3,851	6,493
Available for sale securities	$ 1,066,764	$ 1,055,639

Investment Securities (Investme

Investment Securities (Investment Securities, At Fair Value) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Investment Securities [Abstract]
Available for sale securities	$ 9,109,287	$ 9,649,203
Trading securities	24,605	22,225
Non-marketable	99,268	99,558
Total investment securities	$ 9,233,160	$ 9,770,986

Investment Securities (Summary

Investment Securities (Summary Of Available For Sale Investment Securities By Maturity Groupings) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Investment [Line Items]
Amortized Cost	$ 8,971,612	$ 9,600,330
Fair Value	9,109,287	9,649,203
U.S. Government And Federal Agency Obligations [Member]
Investment [Line Items]
Amortized Cost	916,224	919,904
Fair Value	918,604	920,904
U.S. Government And Federal Agency Obligations [Member] | Available For Sale Securities Maturity Within1 Year [Member]
Investment [Line Items]
Amortized Cost	57,511
Fair Value	58,238
U.S. Government And Federal Agency Obligations [Member] | Available For Sale Securities Maturity After1 But Within5 Years [Member]
Investment [Line Items]
Amortized Cost	570,284
Fair Value	573,789
U.S. Government And Federal Agency Obligations [Member] | Available For Sale Securities Maturity After5 But Within10 Years [Member]
Investment [Line Items]
Amortized Cost	218,912
Fair Value	219,468
U.S. Government And Federal Agency Obligations [Member] | Available For Sale Maturity After10 Years [Member]
Investment [Line Items]
Amortized Cost	69,517
Fair Value	67,109
Government-Sponsored Enterprise Obligations [Member]
Investment [Line Items]
Amortized Cost	470,403	450,448
Fair Value	469,414	449,998
Government-Sponsored Enterprise Obligations [Member] | Available For Sale Securities Maturity Within1 Year [Member]
Investment [Line Items]
Amortized Cost	187,032
Fair Value	187,027
Government-Sponsored Enterprise Obligations [Member] | Available For Sale Securities Maturity After1 But Within5 Years [Member]
Investment [Line Items]
Amortized Cost	247,444
Fair Value	247,141
Government-Sponsored Enterprise Obligations [Member] | Available For Sale Maturity After10 Years [Member]
Investment [Line Items]
Amortized Cost	35,927
Fair Value	35,246
State And Municipal Obligations [Member]
Investment [Line Items]
Amortized Cost	1,687,136	1,778,684
Fair Value	1,720,403	1,778,214
State And Municipal Obligations [Member] | Available For Sale Securities Maturity Within1 Year [Member]
Investment [Line Items]
Amortized Cost	177,616
Fair Value	178,836
State And Municipal Obligations [Member] | Available For Sale Securities Maturity After1 But Within5 Years [Member]
Investment [Line Items]
Amortized Cost	659,012
Fair Value	671,931
State And Municipal Obligations [Member] | Available For Sale Securities Maturity After5 But Within10 Years [Member]
Investment [Line Items]
Amortized Cost	800,504
Fair Value	819,943
State And Municipal Obligations [Member] | Available For Sale Maturity After10 Years [Member]
Investment [Line Items]
Amortized Cost	50,004
Fair Value	49,693
Agency Mortgage-Backed Securities [Member]
Investment [Line Items]
Amortized Cost	2,741,329	2,674,964
Fair Value	2,756,973	2,685,931
Non-Agency Mortgage-Backed Securities [Member]
Investment [Line Items]
Amortized Cost	1,062,079	1,054,446
Fair Value	1,066,764	1,055,639
Asset-Backed Securities [Member]
Investment [Line Items]
Amortized Cost	1,735,004	2,389,176
Fair Value	1,736,966	2,381,301
Total Mortgage And Asset-Backed Securities [Member]
Investment [Line Items]
Amortized Cost	5,538,412	6,118,586
Fair Value	5,560,703	6,122,871
Other Debt Securities [Member]
Investment [Line Items]
Amortized Cost	354,084	327,030
Fair Value	356,641	325,953
Other Debt Securities [Member] | Available For Sale Securities Maturity Within1 Year [Member]
Investment [Line Items]
Amortized Cost	13,388
Fair Value	13,393
Other Debt Securities [Member] | Available For Sale Securities Maturity After1 But Within5 Years [Member]
Investment [Line Items]
Amortized Cost	207,556
Fair Value	210,022
Other Debt Securities [Member] | Available For Sale Securities Maturity After5 But Within10 Years [Member]
Investment [Line Items]
Amortized Cost	133,140
Fair Value	133,226
Equity Securities [Member]
Investment [Line Items]
Amortized Cost	5,353	5,678
Fair Value	$ 83,522	$ 51,263

Investment Securities (Availabl

Investment Securities (Available For Sale Securities Unrealized Gains And Losses, By Security Type) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Investment [Line Items]
Amortized Cost	$ 8,971,612	$ 9,600,330
Available For Sale Securities, Gross Unreailzed Gain at Period End	166,027	109,815
Available For Sale Securities, Gross Unrealized Loss at Period End	(28,352)	(60,942)
Fair Value	9,109,287	9,649,203
U.S. Government And Federal Agency Obligations [Member]
Investment [Line Items]
Amortized Cost	916,224	919,904
Available For Sale Securities, Gross Unreailzed Gain at Period End	6,359	7,312
Available For Sale Securities, Gross Unrealized Loss at Period End	(3,979)	(6,312)
Fair Value	918,604	920,904
Government-Sponsored Enterprise Obligations [Member]
Investment [Line Items]
Amortized Cost	470,403	450,448
Available For Sale Securities, Gross Unreailzed Gain at Period End	844	1,126
Available For Sale Securities, Gross Unrealized Loss at Period End	(1,833)	(1,576)
Fair Value	469,414	449,998
State And Municipal Obligations [Member]
Investment [Line Items]
Amortized Cost	1,687,136	1,778,684
Available For Sale Securities, Gross Unreailzed Gain at Period End	34,952	12,223
Available For Sale Securities, Gross Unrealized Loss at Period End	(1,685)	(12,693)
Fair Value	1,720,403	1,778,214
Agency Mortgage-Backed Securities [Member]
Investment [Line Items]
Amortized Cost	2,741,329	2,674,964
Available For Sale Securities, Gross Unreailzed Gain at Period End	28,827	31,610
Available For Sale Securities, Gross Unrealized Loss at Period End	(13,183)	(20,643)
Fair Value	2,756,973	2,685,931
Non-Agency Mortgage-Backed Securities [Member]
Investment [Line Items]
Amortized Cost	1,062,079	1,054,446
Available For Sale Securities, Gross Unreailzed Gain at Period End	8,536	7,686
Available For Sale Securities, Gross Unrealized Loss at Period End	(3,851)	(6,493)
Fair Value	1,066,764	1,055,639
Asset-Backed Securities [Member]
Investment [Line Items]
Amortized Cost	1,735,004	2,389,176
Available For Sale Securities, Gross Unreailzed Gain at Period End	5,047	3,338
Available For Sale Securities, Gross Unrealized Loss at Period End	(3,085)	(11,213)
Fair Value	1,736,966	2,381,301
Total Mortgage And Asset-Backed Securities [Member]
Investment [Line Items]
Amortized Cost	5,538,412	6,118,586
Available For Sale Securities, Gross Unreailzed Gain at Period End	42,410	42,634
Available For Sale Securities, Gross Unrealized Loss at Period End	(20,119)	(38,349)
Fair Value	5,560,703	6,122,871
Other Debt Securities [Member]
Investment [Line Items]
Amortized Cost	354,084	327,030
Available For Sale Securities, Gross Unreailzed Gain at Period End	3,293	935
Available For Sale Securities, Gross Unrealized Loss at Period End	(736)	(2,012)
Fair Value	356,641	325,953
Equity Securities [Member]
Investment [Line Items]
Amortized Cost	5,353	5,678
Available For Sale Securities, Gross Unreailzed Gain at Period End	78,169	45,585
Available For Sale Securities, Gross Unrealized Loss at Period End	0	0
Fair Value	$ 83,522	$ 51,263

Investment Securities (Cash Flo

Investment Securities (Cash Flow Model Inputs Used To Calculate Credit Losses) (Details)	Sep. 30, 2017
Minimum [Member]
Investment [Line Items]
Prepayment CPR	3.00%
Projected cumulative default	13.00%
Credit support	0.00%
Loss severity	16.00%
Maximum [Member]
Investment [Line Items]
Prepayment CPR	25.00%
Projected cumulative default	50.00%
Credit support	47.00%
Loss severity	63.00%

Investment Securities (Changes

Investment Securities (Changes In Recorded Credit Losses) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016	Dec. 31, 2015
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Credit Losses on Debt Securities Held	$ 14,245	$ 14,228	$ 14,080	$ 14,129
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Additions, No Previous Impairment	98	0
Credit losses on debt securities for which impairment was previously recognized	274	270
Increase in expected cash flows that are recognized over remaining life of security	$ (207)	$ (171)

Investment Securities (Securiti

Investment Securities (Securities With Unrealized Losses And Length Of Impairment Period) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Investment [Line Items]
Less than 12 months, Fair Value	$ 2,236,597	$ 4,036,153
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	18,880	50,837
12 months or longer, Fair Value	756,589	444,252
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	9,472	10,105
Total, Fair Value	2,993,186	4,480,405
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	28,352	60,942
U.S. Government And Federal Agency Obligations [Member]
Investment [Line Items]
Less than 12 months, Fair Value	123,071	349,538
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	3,979	2,823
12 months or longer, Fair Value	0	32,208
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	3,489
Total, Fair Value	123,071	381,746
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	3,979	6,312
Government-Sponsored Enterprise Obligations [Member]
Investment [Line Items]
Less than 12 months, Fair Value	190,141	190,441
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	1,650	1,576
12 months or longer, Fair Value	49,793	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	183	0
Total, Fair Value	239,934	190,441
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	1,833	1,576
State And Municipal Obligations [Member]
Investment [Line Items]
Less than 12 months, Fair Value	95,890	700,779
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	692	12,164
12 months or longer, Fair Value	38,026	15,195
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	993	529
Total, Fair Value	133,916	715,974
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	1,685	12,693
Agency Mortgage-Backed Securities [Member]
Investment [Line Items]
Less than 12 months, Fair Value	887,047	1,147,416
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	9,741	20,638
12 months or longer, Fair Value	223,550	2,150
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	3,442	5
Total, Fair Value	1,110,597	1,149,566
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	13,183	20,643
Non-Agency Mortgage-Backed Securities [Member]
Investment [Line Items]
Less than 12 months, Fair Value	381,896	688,131
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	1,674	6,373
12 months or longer, Fair Value	156,455	34,946
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	2,177	120
Total, Fair Value	538,351	723,077
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	3,851	6,493
Asset-Backed Securities [Member]
Investment [Line Items]
Less than 12 months, Fair Value	488,409	780,209
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	522	5,277
12 months or longer, Fair Value	279,402	358,778
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	2,563	5,936
Total, Fair Value	767,811	1,138,987
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	3,085	11,213
Total Mortgage And Asset-Backed Securities [Member]
Investment [Line Items]
Less than 12 months, Fair Value	1,757,352	2,615,756
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	11,937	32,288
12 months or longer, Fair Value	659,407	395,874
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	8,182	6,061
Total, Fair Value	2,416,759	3,011,630
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	20,119	38,349
Debt Securities [Member]
Investment [Line Items]
Less than 12 months, Fair Value	70,143	179,639
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	622	1,986
12 months or longer, Fair Value	9,363	975
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	114	26
Total, Fair Value	79,506	180,614
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ 736	$ 2,012

Investment Securities (Proceeds

Investment Securities (Proceeds From Sales Of Securities And Components Of Investment Securities Gains And Losses) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017		Sep. 30, 2016
Investment [Line Items]
Proceeds from Sale and Maturity of Available-for-sale Securities				$ 367,453		$ 0
Proceeds from sales of non-marketable securities				1,583		7,946
Total proceeds	[1]			369,036		7,946
Investment securities gains (losses), net		$ (3,037)	$ (1,965)	(2,158)	[1]	(3,704)	[1]
Available-for-sale Securities [Member]
Investment [Line Items]
Loss Realized on Called Bond				(254)		0
Available-for-sale Securities, Gross Realized Gains				592		0
Available-for-sale Securities, Gross Realized Losses				(568)		0
Gain realized on donation				6,707		0
Other-than-temporary impairment recognized on debt securities				(372)		(270)
Non-Marketable [Member]
Investment [Line Items]
Gains realized on sales				645		3,717
Nonmarketable Securities Loss On Sale				(880)		(502)
Fair value adjustments, net				$ (8,028)		$ (6,649)
[1]	Available for sale and non-marketable securities

Goodwill And Other Intangible56

Goodwill And Other Intangible Assets (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of Intangible Assets	$ 338	$ 374	$ 1,000	$ 1,200

Goodwill And Other Intangible57

Goodwill And Other Intangible Assets (Schedule Of Intangible Assets With Estimable Useful Lives) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 38,631	$ 36,942
Accumulated Amortization	(31,227)	(30,211)
Valuation Allowance	(16)	(22)
Net Amount	7,388	6,709
Core Deposit Premium [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	31,270	31,270
Accumulated Amortization	(28,127)	(27,429)
Valuation Allowance	0	0
Net Amount	3,143	3,841
Mortgage Servicing Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	7,361	5,672
Accumulated Amortization	(3,100)	(2,782)
Valuation Allowance	(16)	(22)
Net Amount	$ 4,245	$ 2,868

Goodwill And Other Intangible58

Goodwill And Other Intangible Assets (Schedule Of Estimated Annual Amortization Expense) (Details) $ in Thousands	Sep. 30, 2017USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2,017	$ 1,331
2,018	1,181
2,019	996
2,020	834
2,021	$ 711

Goodwill And Other Intangible59

Goodwill And Other Intangible Assets (Schedule Of Changes In Carrying Amount Of Goodwill And Net Other Intangible Assets) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Goodwill and Intangible Assets [Roll Forward]
Amortization	$ (338)	$ (374)	$ (1,000)	$ (1,200)
Goodwill [Member]
Goodwill and Intangible Assets [Roll Forward]
Originations			0
Amortization			0
Impairment reversal			0
Intangible Assets, Net (Including Goodwill)	138,921		138,921		$ 138,921
Core Deposit Premium [Member]
Goodwill and Intangible Assets [Roll Forward]
Originations			0
Amortization			(698)
Impairment reversal			0
Intangible Assets, Net (Including Goodwill)	3,143		3,143		3,841
Mortgage Servicing Rights [Member]
Goodwill and Intangible Assets [Roll Forward]
Originations			1,689
Amortization			(318)
Impairment reversal			6
Intangible Assets, Net (Including Goodwill)	$ 4,245		$ 4,245		$ 2,868

Goodwill And Other Intangible60

Goodwill And Other Intangible Assets (Schedule Of Goodwill Allocated By Operating Segments) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Goodwill [Line Items]
Goodwill	$ 138,921	$ 138,921
Consumer Segment [Member]
Goodwill [Line Items]
Goodwill	70,721	70,721
Commercial Segment [Member]
Goodwill [Line Items]
Goodwill	67,454	67,454
Wealth Segment [Member]
Goodwill [Line Items]
Goodwill	$ 746	$ 746

Guarantees (Details)

Guarantees (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Guarantor Obligations [Line Items]
Derivative Liabilities	$ 5,979	$ 13,339
Notional amount of underlying interest rate swaps associated with risk participation agreements	1,933,725	$ 1,904,093
Financial Standby Letter Of Credit [Member]
Guarantor Obligations [Line Items]
Standby letters of credit, net liability	2,100
Contractual amount of letters of credit, guaranteed maximum potential future payments	338,400
Risk Participation Agreement [Member] | Indirect Guarantee Of Indebtedness [Member]
Guarantor Obligations [Line Items]
Derivative Liabilities	129
Notional amount of underlying interest rate swaps associated with risk participation agreements	$ 74,900
Minimum [Member] | Risk Participation Agreement [Member]
Guarantor Obligations [Line Items]
Term, in years	3 years
Maximum [Member] | Risk Participation Agreement [Member]
Guarantor Obligations [Line Items]
Term, in years	11 years

Pension Pension (Narrative) (De

Pension Pension (Narrative) (Details)	9 Months Ended
	Sep. 30, 2017USD ($)
Pension (Narrative) [Abstract]
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 5,500,000
Defined Benefit Plan, Estimated Future Employer Contributions in Current Fiscal Year	$ 0

Pension (Net Pension Cost) (Det

Pension (Net Pension Cost) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Pension [Abstract]
Service cost - benefits earned during the period	$ 193	$ 135	$ 450	$ 406
Interest cost on projected benefit obligation	923	986	2,869	2,958
Expected Return on Plan Assets	(1,463)	(1,437)	(4,339)	(4,313)
Amortization of Prior Service Cost	(67)	(68)	(203)	(203)
Amortization of unrecognized net loss	630	647	1,864	1,940
Net periodic pension cost	$ 216	$ 263	$ 641	$ 788

Common Stock (Summary Of Compon

Common Stock (Summary Of Components Used To Calculate Basic And Diluted Income Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income attributable to Commerce Bancshares, Inc.	$ 74,564	$ 68,545	$ 225,028	$ 203,812
Preferred Stock Dividends	2,250	2,250	6,750	6,750
Net Income (Loss) Available to Common Stockholders	$ 72,314	$ 66,295	$ 218,278	$ 197,062
Basic income per common share	$ 0.71	$ 0.65	$ 2.14	$ 1.94
Diluted income per common share	$ 0.71	$ 0.65	$ 2.14	$ 1.93
Basic Income Per Common Share [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income attributable to Commerce Bancshares, Inc.	$ 74,564	$ 68,545	$ 225,028	$ 203,812
Preferred Stock Dividends	2,250	2,250	6,750	6,750
Net Income (Loss) Available to Common Stockholders	72,314	66,295	218,278	197,062
Less income allocated to nonvested restricted stockholders	862	913	2,750	2,747
Net income available to common stockholders	$ 71,452	$ 65,382	$ 215,528	$ 194,315
Weighted average common shares outstanding	100,598	100,198	100,509	100,231
Basic income per common share	$ 0.71	$ 0.65	$ 2.14	$ 1.94
Diluted Income Per Common Share [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net Income (Loss) Available to Common Stockholders, Diluted	$ 72,314	$ 66,295	$ 218,278	$ 197,062
Less income allocated to nonvested restricted stockholders	860	912	2,743	2,743
Net income available to common stockholders	$ 71,454	$ 65,383	$ 215,535	$ 194,319
Weighted average common shares outstanding	100,598	100,198	100,509	100,231
Net effect of the assumed exercise of stock-based awards - based on the treasury stock method using the average market price for the respective periods	336	255	358	248
Weighted average diluted common shares outstanding	100,934	100,453	100,867	100,479
Diluted income per common share	$ 0.71	$ 0.65	$ 2.14	$ 1.93

Common Stock Common Stock (Anti

Common Stock Common Stock (Antidilutive Securities Excluded from Computation of Earnings per Share) (Details) - shares shares in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	139	89

Accumulated Other Comprehensi66

Accumulated Other Comprehensive Income (Schedule Of Accumulated Other Comprehensive Income) (Details) - USD ($)		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016	Dec. 31, 2015
Accumulated other comprehensive income		$ 67,061,000	$ 121,082,000	$ 67,061,000	$ 121,082,000	$ 10,975,000	$ 32,470,000
Other Comprehensive Income Before Reclassifications				95,159,000	140,915,000
Reclassified from Accumulated Oher Comprehensive Income				(4,698,000)	2,007,000
Other Comprehensive Income (Loss), before Tax				90,461,000	142,922,000
Other Comprehensive Income (Loss), Tax				(34,375,000)	(54,310,000)
Other comprehensive income (loss), net of tax		24,991,000	(13,342,000)	56,086,000	88,612,000
Reclassification Where Impairment Was Not Previously Recognized				0	0
Unrealized Gain Loss on Securities OTTI [Member]
Accumulated other comprehensive income	[1]	3,456,000	2,964,000	3,456,000	2,964,000	2,975,000	3,316,000
Other Comprehensive Income Before Reclassifications	[1]			365,000	(837,000)
Reclassified from Accumulated Oher Comprehensive Income	[1]			372,000	270,000
Other Comprehensive Income (Loss), before Tax	[1]			737,000	(567,000)
Other Comprehensive Income (Loss), Tax	[1]			(280,000)	215,000
Other comprehensive income (loss), net of tax	[1]			457,000	(352,000)
Reclassification Where Impairment Was Not Previously Recognized				24,000	0
Unrealized Gain Loss on Securities Other [Member]
Accumulated other comprehensive income	[1]	81,903,000	137,637,000	81,903,000	137,637,000	27,328,000	49,750,000
Other Comprehensive Income Before Reclassifications	[1]			94,794,000	141,752,000
Reclassified from Accumulated Oher Comprehensive Income	[1]			(6,731,000)	0
Other Comprehensive Income (Loss), before Tax	[1]			88,063,000	141,752,000
Other Comprehensive Income (Loss), Tax	[1]			(33,464,000)	(53,865,000)
Other comprehensive income (loss), net of tax	[1]			54,599,000	87,887,000
Reclassification Where Impairment Was Not Previously Recognized				(24,000)	0
Pension Loss [Member]
Accumulated other comprehensive income	[2]	$ (18,298,000)	$ (19,519,000)	(18,298,000)	(19,519,000)	$ (19,328,000)	$ (20,596,000)
Other Comprehensive Income Before Reclassifications	[2]			0	0
Reclassified from Accumulated Oher Comprehensive Income	[2]			1,661,000	1,737,000
Other Comprehensive Income (Loss), before Tax	[2]			1,661,000	1,737,000
Other Comprehensive Income (Loss), Tax	[2]			(631,000)	(660,000)
Other comprehensive income (loss), net of tax	[2]			1,030,000	1,077,000
Reclassification Where Impairment Was Not Previously Recognized				$ 0	$ 0
[1]	The pre-tax amounts reclassified from accumulated other comprehensive income are included in "investment securities gains (losses), net" in the consolidated statements of income.
[2]	The pre-tax amounts reclassified from accumulated other comprehensive income are included in the computation of net periodic pension cost as "amortization of prior service cost" and "amortization of unrecognized net loss" (see Note 6), for inclusion in the consolidated statements of income.

Segments Segments (Narrative) (

Segments Segments (Narrative) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2017USD ($)Locations	Sep. 30, 2016USD ($)	Sep. 30, 2017USD ($)Locations	Sep. 30, 2016USD ($)
Segments [Abstract]
Number of Operating Segments			3
Segment Reporting Information, Intersegment Revenue | $	$ 0	$ 0	$ 0	$ 0
Number Of Locations | Locations	180		180

Segments (Schedule Of Financial

Segments (Schedule Of Financial Information By Segment) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017		Sep. 30, 2016
Segment Reporting Information [Line Items]
Net interest income	$ 182,591	$ 171,243	$ 543,671		$ 506,847
Provision for loan losses	(10,704)	(7,263)	(32,590)		(25,918)
Non-interest income	122,242	119,319	362,392		354,913
Investment securities gains (losses), net	(3,037)	(1,965)	(2,158)	[1]	(3,704)	[1]
Non-interest expense	(184,572)	(181,242)	(555,996)		(535,804)
Income before income taxes	106,520	100,092	315,319		296,334
Consumer Segment [Member]
Segment Reporting Information [Line Items]
Net interest income	70,793	67,375	207,421		201,166
Provision for loan losses	(11,067)	(9,033)	(31,531)		(26,533)
Non-interest income	35,194	34,230	101,211		97,165
Investment securities gains (losses), net	0	0	0		0
Non-interest expense	(72,607)	(70,134)	(217,733)		(209,660)
Income before income taxes	22,313	22,438	59,368		62,138
Commercial Segment [Member]
Segment Reporting Information [Line Items]
Net interest income	82,012	78,514	243,517		231,780
Provision for loan losses	335	2,432	959		3,919
Non-interest income	47,902	49,832	144,781		149,240
Investment securities gains (losses), net	0	0	0		0
Non-interest expense	(71,468)	(71,200)	(219,307)		(211,450)
Income before income taxes	58,781	59,578	169,950		173,489
Wealth Segment [Member]
Segment Reporting Information [Line Items]
Net interest income	11,744	10,782	35,515		32,604
Provision for loan losses	(10)	(5)	(9)		(120)
Non-interest income	40,404	36,676	116,961		107,696
Investment securities gains (losses), net	0	0	0		0
Non-interest expense	(30,528)	(28,172)	(90,323)		(85,116)
Income before income taxes	21,610	19,281	62,144		55,064
Segment Totals [Member]
Segment Reporting Information [Line Items]
Net interest income	164,549	156,671	486,453		465,550
Provision for loan losses	(10,742)	(6,606)	(30,581)		(22,734)
Non-interest income	123,500	120,738	362,953		354,101
Investment securities gains (losses), net	0	0	0		0
Non-interest expense	(174,603)	(169,506)	(527,363)		(506,226)
Income before income taxes	102,704	101,297	291,462		290,691
Other Elimination [Member]
Segment Reporting Information [Line Items]
Net interest income	18,042	14,572	57,218		41,297
Provision for loan losses	38	(657)	(2,009)		(3,184)
Non-interest income	(1,258)	(1,419)	(561)		812
Investment securities gains (losses), net	(3,037)	(1,965)	(2,158)		(3,704)
Non-interest expense	(9,969)	(11,736)	(28,633)		(29,578)
Income before income taxes	$ 3,816	$ (1,205)	$ 23,857		$ 5,643
[1]	Available for sale and non-marketable securities

Derivative Instruments Derivati

Derivative Instruments Derivative Instruments (Narrative) (Details) $ in Millions	Sep. 30, 2017USD ($)
Derivative Instruments (Narrative) [Abstract]
Variation Margin Impact to Positive Fair Values of Cleared Swaps	$ 2.4
Variation Margin Impact to Negative Fair Values of Cleared Swaps	$ 7.3

Derivative Instruments (Schedul

Derivative Instruments (Schedule Of Notional Amounts Of Derivative Instruments) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Derivative [Line Items]
Notional Amount of Derivatives	$ 1,933,725	$ 1,904,093
Interest Rate Swaps [Member]
Derivative [Line Items]
Notional Amount of Derivatives	1,723,448	1,685,099
Interest Rate Caps [Member]
Derivative [Line Items]
Notional Amount of Derivatives	31,923	59,379
Credit Risk Participation Agreements [Member]
Derivative [Line Items]
Notional Amount of Derivatives	112,348	121,514
Foreign Exchange Contracts [Member]
Derivative [Line Items]
Notional Amount of Derivatives	8,783	4,046
Mortgage Loan Commitments [Member]
Derivative [Line Items]
Notional Amount of Derivatives	23,616	12,429
Mortgage Loan Forward Sale Contracts [Member]
Derivative [Line Items]
Notional Amount of Derivatives	1,607	6,626
Forward TBA Contracts [Member]
Derivative [Line Items]
Notional Amount of Derivatives	$ 32,000	$ 15,000

Derivative Instruments (Sched71

Derivative Instruments (Schedule Of Fair Values Of Derivative Instruments) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Other assets	$ 11,650	$ 13,566
Other liabilities	(5,979)	(13,339)
Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Other assets	10,630	12,987
Other liabilities	(5,775)	(12,987)
Interest Rate Caps [Member]
Derivatives, Fair Value [Line Items]
Other assets	29	78
Other liabilities	(29)	(78)
Credit Risk Participation Agreements [Member]
Derivatives, Fair Value [Line Items]
Other assets	56	65
Other liabilities	(129)	(156)
Foreign Exchange Contracts [Member]
Derivatives, Fair Value [Line Items]
Other assets	68	66
Other liabilities	(30)	(4)
Mortgage Loan Commitments [Member]
Derivatives, Fair Value [Line Items]
Other assets	757	355
Other liabilities	0	(6)
Mortgage Loan Forward Sale Contracts [Member]
Derivatives, Fair Value [Line Items]
Other assets	8	0
Other liabilities	0	(63)
Forward TBA Contracts [Member]
Derivatives, Fair Value [Line Items]
Other assets	102	15
Other liabilities	$ (16)	$ (45)

Derivative Instruments (Summary

Derivative Instruments (Summary Of The Effects Of Derivative Instruments On Consolidated Statements Of Income) (Details) - Not Designated as Hedging Instrument [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	$ 332	$ 148	$ 1,193	$ 2,894
Other Non-Interest Income [Member] | Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	702	203	1,301	3,198
Other Non-Interest Income [Member] | Credit Risk Participation Agreements [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	7	50	18	(8)
Other Non-Interest Income [Member] | Foreign Exchange Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	51	(20)	(24)	(12)
Loans Fees And Sales [Member] | Mortgage Loan Commitments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	(114)	86	408	613
Loans Fees And Sales [Member] | Mortgage Loan Forward Sale Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	8	1	70	1
Loans Fees And Sales [Member] | Forward TBA Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	$ (322)	$ (172)	$ (580)	$ (898)

Derivative Instruments Deriva73

Derivative Instruments Derivative Instruments (Balance Sheet Offsetting) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	$ 11,650	$ 13,566
Derivative Asset, Amount Offset by Liabiilty	0	0
Derivative Assets	11,650	13,566
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	5,979	13,339
Derivative Liability, Amount Offset by Asset	0	0
Derivative Liabilities	5,979	13,339
Derivative Subject to Master Netting Agreement [Member]
Derivative Asset, Fair Value, Gross Asset	10,809	13,111
Derivative Asset, Amount Offset by Liabiilty	0	0
Derivative Asset, Net Amount Presented in the Balance Sheet	10,809	13,111
Derivative Asset, Not Offset, Policy Election Deduction	(364)	(3,391)
derivatve asset, fair value of collateral	0	0
Derivative Asset, Fair Value, Amount Offset Against Collateral	10,445	9,720
Derivative Liability, Fair Value, Gross Liability	5,829	13,124
Derivative Liability, Amount Offset by Asset	0	0
Derivative Liability, Net Amount Presented in the Balance Sheet	5,829	13,124
Derivative Liability, Not Offset, Policy Election Deduction	(364)	(3,391)
Derivative Liability, Fair Value of Collateral	(1,692)	(5,292)
Derivative Liability, Fair Value, Amount Offset Against Collateral	3,773	4,441
Derivative Not Subject to Master Netting Agreement [Member]
Derivative Asset, Fair Value, Gross Asset	841	455
Derivative Asset, Amount Offset by Liabiilty	0	0
Derivative Asset, Not Subject to Master Netting Arrangement	841	455
Derivative Liability, Fair Value, Gross Liability	150	215
Derivative Liability, Amount Offset by Asset	0	0
Derivative Liability, Not Subject to Master Netting Arrangement	$ 150	$ 215

Resale and Repurchase Agreeme74

Resale and Repurchase Agreements Resale and Repurchase Agreements (Narrative) (Details) - Collateral Swap [Member] - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Balance Sheet Offsetting [Line Items]
Collateral Swap Agreements	$ 650	$ 550
Collateral Already Posted, Aggregate Fair Value	665.5
Collateral Accepted, Aggregate Fair Value	$ 663.1

Resale and Repurchase Agreeme75

Resale and Repurchase Agreements Resale and Repurchase Agreements (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Balance Sheet Offsetting [Line Items]
Securities purchased under agreements to resell	$ 700,000	$ 725,000
Resale agreement [Member]
Balance Sheet Offsetting [Line Items]
Securities Purchased under Agreements to Resell, Gross	1,350,000	1,275,000
Securities Purchased under Agreements to Resell, Liability	(650,000)	(550,000)
Securities purchased under agreements to resell	700,000	725,000
Securities Purchased under Agreements to Resell, Not Subject to Master Netting Arrangement	0	0
Securities Purchased under Agreements to Resell, Collateral, Obligation to Return Securities	(700,000)	(725,000)
Securities Purchased under Agreements to Resell, Amount Offset Against Collateral	0	0
Repurchase agreement [Member]
Balance Sheet Offsetting [Line Items]
Securities Sold under Agreements to Repurchase, Gross	1,708,074	2,221,065
Securities Sold under Agreements to Repurchase, Asset	(650,000)	(550,000)
Securities Sold under Agreements to Repurchase	1,058,074	1,671,065
Securities Sold under Agreements to Repurchase, Not Subject to Master Netting Arrangement	0	0
Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Securities	(1,058,074)	(1,671,065)
Securities Sold under Agreements to Repurchase, Amount Offset Against Collateral	$ 0	$ 0

Resale and Repurchase Agreeme76

Resale and Repurchase Agreements Remaining Contractual Maturities of Repurchase Agreements (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
U.S. Government And Federal Agency Obligations [Member] | Maturity Overnight [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Assets Sold under Agreements to Repurchase, Repurchase Liability	$ 326,080	$ 294,600
U.S. Government And Federal Agency Obligations [Member] | Maturity up to 90 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Assets Sold under Agreements to Repurchase, Repurchase Liability	0	0
U.S. Government And Federal Agency Obligations [Member] | Maturity over 90 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Assets Sold under Agreements to Repurchase, Repurchase Liability	450,000	300,000
U.S. Government And Federal Agency Obligations [Member] | Total Repurchase Agreements [Member] [Domain]
Assets Sold under Agreements to Repurchase [Line Items]
Assets Sold under Agreements to Repurchase, Repurchase Liability	776,080	594,600
Government-Sponsored Enterprise Obligations [Member] | Maturity Overnight [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Assets Sold under Agreements to Repurchase, Repurchase Liability	186,896	147,694
Government-Sponsored Enterprise Obligations [Member] | Maturity up to 90 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Assets Sold under Agreements to Repurchase, Repurchase Liability	0	0
Government-Sponsored Enterprise Obligations [Member] | Maturity over 90 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Assets Sold under Agreements to Repurchase, Repurchase Liability	0	3,237
Government-Sponsored Enterprise Obligations [Member] | Total Repurchase Agreements [Member] [Domain]
Assets Sold under Agreements to Repurchase [Line Items]
Assets Sold under Agreements to Repurchase, Repurchase Liability	186,896	150,931
Agency Mortgage-Backed Securities [Member] | Maturity Overnight [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Assets Sold under Agreements to Repurchase, Repurchase Liability	317,780	693,851
Agency Mortgage-Backed Securities [Member] | Maturity up to 90 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Assets Sold under Agreements to Repurchase, Repurchase Liability	19,730	24,380
Agency Mortgage-Backed Securities [Member] | Maturity over 90 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Assets Sold under Agreements to Repurchase, Repurchase Liability	200,000	252,473
Agency Mortgage-Backed Securities [Member] | Total Repurchase Agreements [Member] [Domain]
Assets Sold under Agreements to Repurchase [Line Items]
Assets Sold under Agreements to Repurchase, Repurchase Liability	537,510	970,704
Asset-Backed Securities [Member] | Maturity Overnight [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Assets Sold under Agreements to Repurchase, Repurchase Liability	117,588	474,830
Asset-Backed Securities [Member] | Maturity up to 90 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Assets Sold under Agreements to Repurchase, Repurchase Liability	90,000	30,000
Asset-Backed Securities [Member] | Maturity over 90 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Assets Sold under Agreements to Repurchase, Repurchase Liability	0	0
Asset-Backed Securities [Member] | Total Repurchase Agreements [Member] [Domain]
Assets Sold under Agreements to Repurchase [Line Items]
Assets Sold under Agreements to Repurchase, Repurchase Liability	207,588	504,830
Repurchase Agreements [Member] | Maturity Overnight [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Assets Sold under Agreements to Repurchase, Repurchase Liability	948,344	1,610,975
Repurchase Agreements [Member] | Maturity up to 90 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Assets Sold under Agreements to Repurchase, Repurchase Liability	109,730	54,380
Repurchase Agreements [Member] | Maturity over 90 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Assets Sold under Agreements to Repurchase, Repurchase Liability	650,000	555,710
Repurchase Agreements [Member] | Total Repurchase Agreements [Member] [Domain]
Assets Sold under Agreements to Repurchase [Line Items]
Assets Sold under Agreements to Repurchase, Repurchase Liability	$ 1,708,074	$ 2,221,065

Stock-Based Compensation (Narra

Stock-Based Compensation (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Jan. 01, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	$ 3,000			$ 2,600	$ 9,100	$ 8,900
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets							$ 1,300
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Net Income	$ 619	$ 1,600	$ 4,500
Nonvested Stock Award [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)					4 years
Nonvested Stock Award [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)					7 years
Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)					4 years
Contractual terms of stock options granted (in years)					10 years

Stock-Based Compensation (Summa

Stock-Based Compensation (Summary Of The Status Of Nonvested Share Awards) (Details)	9 Months Ended
	Sep. 30, 2017$ / sharesshares
Nonvested Share Awards [Roll Forward]
Nonvested, Shares, Beginning Balance | shares	1,392,451
Granted, Shares | shares	242,244
Vested, Shares | shares	(403,586)
Forfeited, Shares | shares	(20,250)
Nonvested, Shares, Ending Balance | shares	1,210,859
Nonvested, Weighted Average Grant Date Fair Value, Beginning Balance | $ / shares	$ 34.67
Granted , Weighted Average Grant Date Fair Value | $ / shares	57.31
Vested , Weighted Average Grant Date Fair Value | $ / shares	30.87
Forfeited , Weighted Average Grant Date Fair Value | $ / shares	40.72
Nonvested , Weighted Average Grant Date Fair Value, Ending Balance | $ / shares	$ 40.36

Stock-Based Compensation Stock-

Stock-Based Compensation Stock-Based Compensation (Current Year Per Share Average Fair Value and Valuation Model Assumptions) (Details)	9 Months Ended
	Sep. 30, 2017$ / shares
Current Year Per Share Average Fair Value and Valuation Model Assumptions [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 12.54
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	1.60%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate	21.10%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate	2.40%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term	7 years

Stock-Based Compensation (Sum80

Stock-Based Compensation (Summary Of SAR Activity) (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Stock Appreciation Rights [Roll Forward]
Outstanding, Shares	1,162,640	1,324,954
Granted, Shares	165,592
Forfeited, Shares	(9,448)
Expired, Shares	(837)
Exercised, Shares	(317,621)
Outstanding, Weighted Average Exercise Price, Beginning Balance	$ 34.53
Granted, Weighted Average Exercise Price	57.53
Forfeited, Weighted Average Exercise Price	44.25
Expired, Weighted Average Exercise Price	36.48
Exercised, Weighted Average Exercise Price	30.86
Outstanding, Weighted Average Exercise Price, Ending Balance	$ 38.73
Outstanding, Weighted Average Remaining Contractual Term (in years)	6 years 4 months
Outstanding, Aggregate Intrinsic Value, Ending Balance	$ 21,821

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Private equity investments	$ 50,254	$ 50,820
Fair Value Hierarchy, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Auction Rate Securities Available For Sale	16,900
Private equity investments	$ 50,254	$ 50,820

Fair Value Measurements (Summar

Fair Value Measurements (Summary Of Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgages Held-for-sale, Fair Value Disclosure	$ 11,320,000	$ 9,263,000
U.S. government and federal agency obligations	918,604,000	920,904,000
Government-sponsored enterprise obligations	469,414,000	449,998,000
State and municipal obligations	1,720,403,000	1,778,214,000
Agency mortgage-backed securities	2,756,973,000	2,685,931,000
Non-agency mortgage-backed securities	1,066,764,000	1,055,639,000
Other asset-backed securities	1,736,966,000	2,381,301,000
Other debt securities	356,641,000	325,953,000
Equity securities	83,522,000	51,263,000
Trading securities	24,605,000	22,225,000
Private equity investments	50,254,000	50,820,000
Derivative Assets	11,650,000	13,566,000
Assets held in trust for deferred compensation plan	12,311,000	10,261,000
Total Assets	9,219,427,000	9,755,338,000
Derivative Liabilities	5,979,000	13,339,000
Liabilities held in trust for deferred compensation plan	12,311,000	10,261,000
Total Liabilities	18,290,000	23,600,000
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgages Held-for-sale, Fair Value Disclosure	0	0
U.S. government and federal agency obligations	918,604,000	920,904,000
Government-sponsored enterprise obligations	0	0
State and municipal obligations	0	0
Agency mortgage-backed securities	0	0
Non-agency mortgage-backed securities	0	0
Other asset-backed securities	0	0
Other debt securities	0	0
Equity securities	32,915,000	24,967,000
Trading securities	0	0
Private equity investments	0	0
Derivative Assets	0	0
Assets held in trust for deferred compensation plan	12,311,000	10,261,000
Total Assets	963,830,000	956,132,000
Derivative Liabilities	0	0
Liabilities held in trust for deferred compensation plan	12,311,000	10,261,000
Total Liabilities	12,311,000	10,261,000
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgages Held-for-sale, Fair Value Disclosure	11,320,000	9,263,000
U.S. government and federal agency obligations	0	0
Government-sponsored enterprise obligations	469,414,000	449,998,000
State and municipal obligations	1,703,550,000	1,761,532,000
Agency mortgage-backed securities	2,756,973,000	2,685,931,000
Non-agency mortgage-backed securities	1,066,764,000	1,055,639,000
Other asset-backed securities	1,736,966,000	2,381,301,000
Other debt securities	356,641,000	325,953,000
Equity securities	50,607,000	26,296,000
Trading securities	24,605,000	22,225,000
Private equity investments	0	0
Derivative Assets	10,837,000	13,146,000
Assets held in trust for deferred compensation plan	0	0
Total Assets	8,187,677,000	8,731,284,000
Derivative Liabilities	5,850,000	13,177,000
Liabilities held in trust for deferred compensation plan	0	0
Total Liabilities	5,850,000	13,177,000
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgages Held-for-sale, Fair Value Disclosure	0	0
U.S. government and federal agency obligations	0	0
Government-sponsored enterprise obligations	0	0
State and municipal obligations	16,853,000	16,682,000
Agency mortgage-backed securities	0	0
Non-agency mortgage-backed securities	0	0
Other asset-backed securities	0	0
Other debt securities	0	0
Equity securities	0	0
Trading securities	0	0
Private equity investments	50,254,000	50,820,000
Derivative Assets	813,000	420,000
Assets held in trust for deferred compensation plan	0	0
Total Assets	67,920,000	67,922,000
Derivative Liabilities	129,000	162,000
Liabilities held in trust for deferred compensation plan	0	0
Total Liabilities	$ 129,000	$ 162,000

Fair Value Measurements (Summ83

Fair Value Measurements (Summary Of Changes In Level 3 Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 71,173	$ 80,994	$ 67,760	$ 80,296
Total gains or losses (realized /unrealized), included in earnings	(5,305)	(2,785)	(7,602)	(6,040)
Total gains or losses (realized /unrealized), included in other comprehensive income	19	317	729	819
Investment securities called	0	(1,100)	(600)	(1,200)
Discount accretion	9	12	42	94
Purchase of private equity securities	2,185	2,894	9,269	8,735
Sales And Repayments Of Private Equity Securities	(290)	(3,315)	(1,840)	(5,713)
Capitalized interest/dividends	0	15	33	77
Sale Of Risk Participation Agreement	0	(33)	0	(69)
Ending balance	67,791	76,999	67,791	76,999
Total gains or losses included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end	(4,434)	(1,995)	(7,078)	(5,677)
State And Municipal Obligations [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	16,825	17,679	16,682	17,195
Total gains or losses (realized /unrealized), included in earnings	0	0	0	0
Total gains or losses (realized /unrealized), included in other comprehensive income	19	317	729	819
Investment securities called	0	(1,100)	(600)	(1,200)
Discount accretion	9	12	42	94
Purchase of private equity securities	0	0	0	0
Sales And Repayments Of Private Equity Securities	0	0	0	0
Capitalized interest/dividends	0	0	0	0
Sale Of Risk Participation Agreement	0	0	0	0
Ending balance	16,853	16,908	16,853	16,908
Total gains or losses included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end	0	0	0	0
Private Equity Funds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	53,557	62,813	50,820	63,032
Total gains or losses (realized /unrealized), included in earnings	(5,198)	(2,921)	(8,028)	(6,645)
Total gains or losses (realized /unrealized), included in other comprehensive income	0	0	0	0
Investment securities called	0	0	0	0
Discount accretion	0	0	0	0
Purchase of private equity securities	2,185	2,894	9,269	8,735
Sales And Repayments Of Private Equity Securities	(290)	(3,315)	(1,840)	(5,713)
Capitalized interest/dividends	0	15	33	77
Sale Of Risk Participation Agreement	0	0	0	0
Ending balance	50,254	59,486	50,254	59,486
Total gains or losses included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end	(5,198)	(2,921)	(7,853)	(6,545)
Derivative Level Three Unobservable Inputs [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	791	502	258	69
Total gains or losses (realized /unrealized), included in earnings	(107)	136	426	605
Total gains or losses (realized /unrealized), included in other comprehensive income	0	0	0	0
Investment securities called	0	0	0	0
Discount accretion	0	0	0	0
Purchase of private equity securities	0	0	0	0
Sales And Repayments Of Private Equity Securities	0	0	0	0
Capitalized interest/dividends	0	0	0	0
Sale Of Risk Participation Agreement	0	(33)	0	(69)
Ending balance	684	605	684	605
Total gains or losses included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end	$ 764	$ 926	$ 775	$ 868

Fair Value Measurements (Summ84

Fair Value Measurements (Summary Of Gains And Losses On Level 3 Assets And Liabilities) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Gains and Losses included in earnings for Level 3 assets & liabilities [Line Items]
Total gains or losses included in earnings	$ (5,305)	$ (2,785)	$ (7,602)	$ (6,040)
Change in unrealized gains or losses relating to assets still held	(4,434)	(1,995)	(7,078)	(5,677)
Loans Fees And Sales [Member]
Gains and Losses included in earnings for Level 3 assets & liabilities [Line Items]
Total gains or losses included in earnings	(115)	86	407	613
Change in unrealized gains or losses relating to assets still held	756	876	756	876
Other Non-Interest Income [Member]
Gains and Losses included in earnings for Level 3 assets & liabilities [Line Items]
Total gains or losses included in earnings	8	50	19	(8)
Change in unrealized gains or losses relating to assets still held	8	50	19	(8)
Investment Securities Gains (Losses), Net [Member]
Gains and Losses included in earnings for Level 3 assets & liabilities [Line Items]
Total gains or losses included in earnings	(5,198)	(2,921)	(8,028)	(6,645)
Change in unrealized gains or losses relating to assets still held	$ (5,198)	$ (2,921)	$ (7,853)	$ (6,545)

Fair Value Measurements (Summ85

Fair Value Measurements (Summary Of Quantitative Information About Level 3 Fair Value Measurements) (Details)	9 Months Ended
	Sep. 30, 2017Rate
Auction Rate Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Valuation Technique, Discounted cash flow	Discounted cash flow
Unobservable Input, Estimated market recovery period	5 years
Auction Rate Securities [Member] | Minimum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unobservable Input, Estimated market rate	2.80%
Auction Rate Securities [Member] | Maximum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unobservable Input, Estimated market rate	3.10%
Private Equity Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Valuation Technique, Market comparable companies	Market comparable companies
Private Equity Investments [Member] | Minimum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Earnings before Interest, Taxes, Depreciation, and Amortization Multiple	4
Private Equity Investments [Member] | Maximum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Earnings before Interest, Taxes, Depreciation, and Amortization Multiple	5.8
Mortgage Loan Commitments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Valuation Technique, Discounted cash flow	Discounted cash flow
Weighted Average, Probability of Funding	79.10%
Weighted Average, Embedded Servicing Value	1.10%
Mortgage Loan Commitments [Member] | Minimum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Probability of Funding	50.90%
Embedded Servicing Value	(0.30%)
Mortgage Loan Commitments [Member] | Maximum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Probability of Funding	100.00%
Embedded Servicing Value	2.20%

Fair Value Measurements (Schedu

Fair Value Measurements (Schedule of Fair Value Disclosures Measured On Nonrecurring Basis) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Collateral Dependent Impaired Loans	$ 1,468	$ 1,756
Loans Nonrecurring Basis Gains Losses	(336)	(1,626)
Mortgage servicing rights	4,245	2,533
Mortgage Servicing Rights Nonrecurring Basis Gains Losses	6	(7)
Foreclosed assets	50	47
Foreclosed Assets Nonrecurring Basis Gains Losses	(83)	(66)
Long-lived assets	3,033	2,232
Long Lived Assets Nonrecurring Basis Gains Losses	(1,167)	(1,001)
Fair Value, Inputs, Level 1 [Member]
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Collateral Dependent Impaired Loans	0	0
Mortgage servicing rights	0	0
Foreclosed assets	0	0
Long-lived assets	0	0
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Collateral Dependent Impaired Loans	0	0
Mortgage servicing rights	0	0
Foreclosed assets	0	0
Long-lived assets	0	0
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Collateral Dependent Impaired Loans	1,468	1,756
Mortgage servicing rights	4,245	2,533
Foreclosed assets	50	47
Long-lived assets	$ 3,033	$ 2,232

Fair Value Of Financial Instr87

Fair Value Of Financial Instruments (Schedule Of Estimated Fair Value Of Financial Instruments) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of Personal Real Estate Loans Held for Sale	$ 11,300
Available for sale securities	9,109,287	$ 9,649,203
Trading securities	24,605	22,225
Non-marketable	99,268	99,558
Securities purchased under agreements to resell	700,000	725,000
Cash and due from banks	461,724	494,690
Derivative Assets	11,650	13,566
Assets held in trust for deferred compensation plan	12,311	10,261
Non-interest bearing deposits	7,536,127	7,429,398
Savings, interest checking and money market deposits	11,091,200	11,430,789
Derivative Liabilities	5,979	13,339
Liabilities held in trust for deferred compensation plan	12,311	10,261
Fair Value Hierarchy, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0	0
Derivative Assets	0	0
Assets held in trust for deferred compensation plan	12,311	10,261
Derivative Liabilities	0	0
Liabilities held in trust for deferred compensation plan	12,311	10,261
Fair Value Hierarchy, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	24,605	22,225
Derivative Assets	10,837	13,146
Assets held in trust for deferred compensation plan	0	0
Derivative Liabilities	5,850	13,177
Liabilities held in trust for deferred compensation plan	0	0
Fair Value Hierarchy, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0	0
Derivative Assets	813	420
Assets held in trust for deferred compensation plan	0	0
Derivative Liabilities	129	162
Liabilities held in trust for deferred compensation plan	0	0
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Fair Value Hierarchy, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	951,519	945,871
Federal funds sold	32,630	15,470
Interest earning deposits with banks	105,422	272,275
Cash and due from banks	461,724	494,690
Assets held in trust for deferred compensation plan	12,311	10,261
Non-interest bearing deposits	7,536,127	7,429,398
Savings, interest checking and money market deposits	11,091,200	11,430,789
Federal Funds Purchased	350,910	52,840
Liabilities held in trust for deferred compensation plan	12,311	10,261
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Fair Value Hierarchy, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of Personal Real Estate Loans Held for Sale	17,337	14,456
Available for sale securities	8,140,915	8,686,650
Trading securities	24,605	22,225
Derivative Assets	10,837	13,146
Derivative Liabilities	5,850	13,177
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Fair Value Hierarchy, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	16,853	16,682
Non-marketable	99,268	99,558
Securities purchased under agreements to resell	700,000	725,000
Derivative Assets	813	420
Time open and certificates of deposits	1,816,446	2,240,908
Securities Sold under Agreements to Repurchase	1,058,074	1,671,065
Other borrowings	102,553	102,049
Derivative Liabilities	129	162
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Fair Value Hierarchy, Level 3 [Member] | Business [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	4,834,037	4,776,365
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Fair Value Hierarchy, Level 3 [Member] | Real Estate - Construction And Land [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	921,609	791,236
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Fair Value Hierarchy, Level 3 [Member] | Real Estate - Business [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	2,700,174	2,643,374
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Fair Value Hierarchy, Level 3 [Member] | Real Estate - Personal [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	2,029,302	2,010,397
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Fair Value Hierarchy, Level 3 [Member] | Consumer [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	2,113,438	1,990,801
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Fair Value Hierarchy, Level 3 [Member] | Revolving Home Equity [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	391,308	413,634
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Fair Value Hierarchy, Level 3 [Member] | Consumer Credit Card [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	752,379	776,465
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Fair Value Hierarchy, Level 3 [Member] | Overdrafts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	3,245	10,464
Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value Hierarchy, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	951,519	945,871
Federal funds sold	32,630	15,470
Interest earning deposits with banks	105,422	272,275
Cash and due from banks	461,724	494,690
Assets held in trust for deferred compensation plan	12,311	10,261
Non-interest bearing deposits	7,536,127	7,429,398
Savings, interest checking and money market deposits	11,091,200	11,430,789
Federal Funds Purchased	350,910	52,840
Liabilities held in trust for deferred compensation plan	12,311	10,261
Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value Hierarchy, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value of Personal Real Estate Loans Held for Sale	17,337	14,456
Available for sale securities	8,140,915	8,686,650
Trading securities	24,605	22,225
Derivative Assets	10,837	13,146
Derivative Liabilities	5,850	13,177
Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value Hierarchy, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	16,853	16,682
Non-marketable	99,268	99,558
Securities purchased under agreements to resell	702,989	728,179
Derivative Assets	813	420
Time open and certificates of deposits	1,820,178	2,235,218
Securities Sold under Agreements to Repurchase	1,058,459	1,671,227
Other borrowings	103,012	104,298
Derivative Liabilities	129	162
Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value Hierarchy, Level 3 [Member] | Business [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	4,848,169	4,787,469
Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value Hierarchy, Level 3 [Member] | Real Estate - Construction And Land [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	933,862	800,426
Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value Hierarchy, Level 3 [Member] | Real Estate - Business [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	2,712,002	2,658,093
Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value Hierarchy, Level 3 [Member] | Real Estate - Personal [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	2,034,374	2,005,227
Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value Hierarchy, Level 3 [Member] | Consumer [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	2,088,302	1,974,784
Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value Hierarchy, Level 3 [Member] | Revolving Home Equity [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	391,419	414,499
Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value Hierarchy, Level 3 [Member] | Consumer Credit Card [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	767,344	794,856
Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value Hierarchy, Level 3 [Member] | Overdrafts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	$ 3,245	$ 10,464