Synovus Financial (SNV) 10-Q 6 Nov 18 2018 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Nov. 05, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Entity Registrant Name	SYNOVUS FINANCIAL CORP
Entity Central Index Key	18,349
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Common Stock, Shares Outstanding		116,376,039

CONSOLIDATED BALANCE SHEETS (un

CONSOLIDATED BALANCE SHEETS (unaudited) - USD ($) $ in Thousands		Sep. 30, 2018	Dec. 31, 2017
ASSETS
Cash and due from banks		$ 436,540	$ 397,848
Interest-bearing funds with Federal Reserve Bank		515,493	460,928
Interest earning deposits with banks		34,470	26,311
Federal funds sold and securities purchased under resale agreements		25,430	47,846
Total cash, cash equivalents, restricted cash, and restricted cash equivalents	[1]	1,011,933	932,933
Mortgage loans held for sale, at fair value		37,276	48,024
Investment securities available for sale, at fair value		3,883,574	3,987,069
Loans, net of deferred fees and costs		25,577,116	24,787,464
Allowance for loan losses		(251,450)	(249,268)
Loans, net		25,325,666	24,538,196
Cash surrender value of bank-owned life insurance		551,061	540,958
Premises and equipment, net		431,012	426,813
Goodwill		57,315	57,315
Other intangible assets		10,166	11,254
Deferred tax asset, net		185,116	165,788
Other assets		582,001	513,487
Total assets		32,075,120	31,221,837
Deposits:
Non-interest-bearing deposits		7,628,736	7,686,339
Interest-bearing deposits		18,804,922	18,461,561
Total deposits		26,433,658	26,147,900
Federal funds purchased and securities sold under repurchase agreements		191,145	161,190
Other short-term borrowings		478,540	100,000
Long-term debt		1,656,909	1,606,138
Other liabilities		274,795	245,043
Total liabilities		29,035,047	28,260,271
Shareholders' Equity
Common stock - $1.00 par value. Authorized 342,857,143 shares; 143,093,317 issued at September 30, 2018 and 142,677,449 issued at December 31, 2017; 116,714,463 outstanding at September 30, 2018 and 118,897,295 outstanding at December 31, 2017		143,093	142,678
Additional paid-in capital		3,049,233	3,043,129
Treasury stock, at cost – 26,378,854 shares at September 30, 2018 and 23,780,154 shares at December 31, 2017		(974,478)	(839,674)
Accumulated other comprehensive loss		(143,720)	(54,754)
Retained earnings		770,807	544,207
Total shareholders’ equity		3,040,073	2,961,566
Total liabilities and shareholders' equity		32,075,120	31,221,837
Series D Preferred Stock
Shareholders' Equity
Preferred Stock		195,138	0
Series C Preferred Stock
Shareholders' Equity
Preferred Stock		$ 0	$ 125,980
[1]	See "Note 1 - Basis of Presentation" of this Report for information on Synovus' change in presentation of cash and cash equivalents.

CONSOLIDATED BALANCE SHEETS (_2

CONSOLIDATED BALANCE SHEETS (unaudited) (Parenthetical) - $ / shares	Sep. 30, 2018	Dec. 31, 2017
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	342,857,143	342,857,143
Common stock, shares issued (in shares)	143,093,317	142,677,449
Common stock, shares outstanding (in shares)	116,714,463	118,897,295
Treasury stock, shares at cost (in shares)	26,378,854	23,780,154
Series D Preferred Stock
Preferred Stock, shares authorized (in shares)	100,000,000
Preferred Stock, shares issued (in shares)	8,000,000
Preferred stock, shares outstanding (in shares)	8,000,000
Series C Preferred Stock
Preferred Stock, shares issued (in shares)	0	5,200,000
Preferred stock, shares outstanding (in shares)	0	5,200,000

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME (unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Interest income:
Loans, including fees	$ 314,639	$ 273,847	$ 900,035	$ 785,166
Investment securities available for sale	24,164	20,014	71,976	60,112
Mortgage loans held for sale	578	506	1,514	1,478
Federal Reserve Bank balances	2,376	1,569	6,944	4,084
Other earning assets	2,185	1,716	6,442	4,723
Total interest income	343,942	297,652	986,911	855,563
Interest expense:
Deposits	39,219	20,798	98,195	55,874
Federal funds purchased, securities sold under repurchase agreements, and other short-term borrowings	940	347	2,744	865
Long-term debt	12,164	13,935	35,492	45,227
Total interest expense	52,323	35,080	136,431	101,966
Net interest income	291,619	262,572	850,480	753,597
Provision for loan losses	14,982	39,686	39,548	58,620
Net interest income after provision for loan losses	276,637	222,886	810,932	694,977
Non-interest income:
Revenue from contract with customers	55,849	52,320	166,514	155,643
Income from bank-owned life insurance	3,771	3,232	11,720	9,560
Cabela's Transaction Fee	0	75,000	0	75,000
Investment securities losses, net	0	(7,956)	(1,296)	(289)
Other non-interest income	4,116	3,929	12,147	8,526
Total non-interest income	71,668	135,435	212,101	275,974
Non-interest expense:
Salaries and other personnel expense	114,341	109,675	339,924	322,079
Net occupancy and equipment expense	32,088	30,573	96,222	89,837
Third-party processing expense	14,810	13,659	43,822	39,882
FDIC insurance and other regulatory fees	6,430	7,078	19,765	20,723
Professional fees	6,298	7,141	18,087	20,048
Advertising expense	3,735	3,610	14,046	14,868
Foreclosed real estate expense, net	360	7,265	1,110	10,847
Earnout liability adjustments	11,652	2,059	11,652	3,766
Merger-related expense	6,684	23	6,684	110
Restructuring charges, net	21	519	(191)	7,043
Other operating expenses	23,878	24,044	68,410	65,577
Total non-interest expense	220,297	205,646	619,531	594,780
Income before income taxes	128,008	152,675	403,502	376,171
Income tax expense	18,949	54,668	80,095	130,303
Net income	109,059	98,007	323,407	245,868
Less: Preferred stock dividends and redemption charge	9,729	2,559	14,848	7,678
Net income available to common shareholders	$ 99,330	$ 95,448	$ 308,559	$ 238,190
Net income per common share, basic (in dollars per share)	$ 0.85	$ 0.79	$ 2.61	$ 1.96
Net income per common share, diluted (in dollars per share)	$ 0.84	$ 0.78	$ 2.60	$ 1.94
Weighted average common shares outstanding, basic (in shares)	117,241	120,900	118,096	121,796
Weighted average common shares outstanding, diluted (in shares)	118,095	121,814	118,847	122,628
Service charges on deposit accounts
Non-interest income:
Revenue from contract with customers	$ 20,582	$ 20,678	$ 60,521	$ 61,048
Fiduciary and asset management fees
Non-interest income:
Revenue from contract with customers	13,462	12,615	40,881	37,290
Card fees
Non-interest income:
Revenue from contract with customers	10,608	9,729	31,640	29,614
Brokerage revenue
Non-interest income:
Revenue from contract with customers	9,329	7,511	26,924	21,947
Mortgage banking income
Non-interest income:
Revenue from contract with customers	5,290	5,603	15,177	17,151
Other fee income
Non-interest income:
Revenue from contract with customers	$ 4,510	$ 5,094	$ 14,387	$ 16,127

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income, Before-tax Amount	$ 128,008	$ 152,675	$ 403,502	$ 376,171
Net income, Tax (Expense) Benefit	(18,949)	(54,668)	(80,095)	(130,303)
Net income	109,059	98,007	323,407	245,868
Net change related to cash flow hedges:
Reclassification adjustment for losses realized in net income, Before-tax Amount			0	130
Reclassification adjustment for losses realized in net income, Tax (Expense) Benefit			0	(50)
Reclassification adjustment for losses realized in net income, Net of Tax Amount			0	80
Net unrealized gains on investment securities available for sale:
Reclassification adjustment for net losses realized in net income, Before-tax Amount	0	7,956	1,296	289
Net unrealized gains arising during the period, Before-tax Amount	(24,210)	5,465	(111,131)	25,715
Net unrealized gain, Before-tax Amount	(24,210)	13,421	(109,835)	26,004
Net unrealized gains on investment securities available for sale: Tax (Expense) Benefit
Reclassification adjustment for net losses realized in net income, Tax (Expense) Benefit	0	(3,063)	(336)	(111)
Net unrealized gains arising during the period, Tax (Expense) Benefit	6,270	(2,106)	28,782	(9,903)
Net unrealized gains, Tax (Expense) Benefit	6,270	(5,169)	28,446	(10,014)
Net unrealized gains on investment securities available for sale: Net of Tax Amount
Reclassification adjustment for net losses realized in net income, Net of Tax Amount	0	4,893	960	178
Net unrealized gains arising during the period, Net of Tax Amount	(17,940)	3,359	(82,349)	15,812
Net unrealized gains, Net of Tax Amount	(17,940)	8,252	(81,389)	15,990
Post-retirement unfunded health benefit: Before-tax Amount
Reclassification adjustment for gains realized in net income, Before-tax Amount	(35)	(34)	(103)	(74)
Actuarial (losses) gains arising during the period, Before tax Amount	(46)	61	(46)	61
Net increase (decrease) in unrealized gains, Before-tax Amount	(81)	27	(149)	(13)
Post-retirement unfunded health benefit: Tax (Expense) Benefit
Reclassification adjustment for gains realized in net income, Tax (Expense) Benefit	9	13	31	29
Actuarial (losses) gains arising during the period, Tax (Expense) Benefit	12	(23)	12	(23)
Net increase (decrease) in unrealized gains, Tax (Expense) Benefit	21	(10)	43	6
Post-retirement unfunded health benefit: Net of Tax Amount
Reclassification adjustment for gains realized in net income, Net of Tax Amount	(26)	(21)	(72)	(45)
Actuarial (losses) gains arising during the period, Net of Tax Amount	(34)	38	(34)	38
Net increase (decrease) in unrealized gains, Net of Tax Amount	(60)	17	(106)	(7)
Other comprehensive income (loss), Before-tax Amount	(24,291)	13,448	(109,984)	26,121
Other comprehensive income (loss), Tax (Expense) Benefit	6,291	(5,179)	28,489	(10,058)
Other comprehensive income (loss), Net of Tax Amount	(18,000)	8,269	(81,495)	16,063
Comprehensive income, Net of Tax Amount	$ 91,059	$ 106,276	$ 241,912	$ 261,931

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (unaudited) - USD ($) $ in Thousands	Total	Series D Preferred Stock	Series C Preferred Stock	Preferred StockSeries D Preferred Stock	Preferred StockSeries C Preferred Stock	Common Stock	Additional Paid-in Capital	Treasury Stock	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Retained EarningsSeries D Preferred Stock	Retained EarningsSeries C Preferred Stock
Balance at Dec. 31, 2016	$ 2,927,924			$ 0	$ 125,980	$ 142,026	$ 3,028,405	$ (664,595)	$ (55,659)	$ 351,767
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	245,868									245,868
Other comprehensive income (loss), net of income taxes	16,063								16,063
Cash dividends declared on common stock	(54,671)									(54,671)
Cash dividends paid on Preferred Stock	(7,678)									(7,678)
Repurchases of common stock	(135,914)							(135,914)
Restricted share unit activity	(7,962)					335	(8,007)			(290)
Stock options exercised	2,872					164	2,708
Share-based compensation expense	10,576						10,576
Balance at Sep. 30, 2017	2,997,078			0	125,980	142,525	3,033,682	(800,509)	(39,596)	534,996
Balance at Jun. 30, 2017									(47,865)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income (loss), net of income taxes	8,269								8,269
Balance at Sep. 30, 2017	2,997,078			0	125,980	142,525	3,033,682	(800,509)	(39,596)	534,996
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of ASU	0
Adoption of ASU | ASU 2014-09	(685)									(685)
Adoption of ASU | ASU 2018-02	0								(7,588)	7,588
Adoption of ASU | ASU 2016-01	0								117	(117)
Balance at Dec. 31, 2017	2,961,566			0	125,980	142,678	3,043,129	(839,674)	(54,754)	544,207
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	323,407									323,407
Other comprehensive income (loss), net of income taxes	(81,495)								(81,495)
Cash dividends declared on common stock	(88,396)									(88,396)
Cash dividends paid on Preferred Stock		$ (3,150)	$ (7,678)								$ (3,150)	$ (7,678)
Repurchases of common stock	(134,804)		$ (130,000)		(125,980)			(134,804)				$ (4,020)
Issuance of Series D Preferred Stock, net of issuance costs	195,138			195,138
Restricted share unit activity	(8,411)					293	(8,355)			(349)
Stock options exercised	2,077					122	1,955
Share-based compensation expense	12,504						12,504
Balance at Sep. 30, 2018	3,040,073			195,138	0	143,093	3,049,233	(974,478)	(143,720)	770,807
Balance at Jun. 30, 2018									(125,720)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income (loss), net of income taxes	(18,000)								(18,000)
Balance at Sep. 30, 2018	3,040,073			$ 195,138	$ 0	$ 143,093	$ 3,049,233	$ (974,478)	$ (143,720)	$ 770,807
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of ASU	(685)
Adoption of ASU | ASU 2016-01	$ 3,200

CONSOLIDATED STATEMENTS OF CH_2

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (unaudited) (Parenthetical) - $ / shares	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Statement of Stockholders' Equity [Abstract]
Cash dividends declared on common stock (USD per share)	$ 0.75	$ 0.45

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018		Sep. 30, 2017
Operating Activities
Net income	$ 323,407		$ 245,868
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	39,548		58,620
Depreciation, amortization, and accretion, net	41,716		44,786
Deferred income tax expense	9,360		114,205
Originations of mortgage loans held for sale	(429,531)		(490,202)
Proceeds from sales of mortgage loans held for sale	449,651		500,786
Gain on sales of mortgage loans held for sale, net	(9,886)		(10,587)
Increase in other assets	(82,608)		(6,678)
Increase in other liabilities	17,690		17,718
Investment securities losses, net	1,296		289
Share-based compensation expense	12,504		10,576
Net cash provided by operating activities	373,147		485,381
Investing Activities
Proceeds from maturities and principal collections of investment securities available for sale	457,151		483,307
Proceeds from sales of investment securities available for sale	35,066		812,293
Purchases of investment securities available for sale	(510,797)		(1,195,302)
Proceeds from sales of loans	15,454		26,386
Proceeds from sales of other real estate and other assets	8,676		11,517
Net increase in loans including purchases of loans	(842,383)		(755,231)
Purchases of bank-owned life insurance policies, net of settlements	1,783		(150,000)
Net increase in premises and equipment	(39,034)		(34,717)
Net cash used in investing activities	(874,084)		(801,747)
Financing Activities
Net (decrease) increase in demand and savings deposits	(152,313)		335,438
Net increase in certificates of deposit	437,655		1,202,926
Net increase (decrease) in federal funds purchased and securities sold under repurchase agreements	29,955		(18,160)
Net change in other short-term borrowings	378,540		0
Repayments and redemption of long-term debt	(2,230,052)		(1,653,613)
Proceeds from issuance of long-term debt	2,280,000		1,375,000
Dividends paid to common shareholders	(77,020)		(36,681)
Dividends paid to preferred shareholders	(10,828)		(7,678)
Proceeds from issuance of Series D Preferred Stock	195,138		0
Redemption of Series C Preferred Stock	(130,000)		0
Stock options exercised	2,077		2,872
Repurchase of common stock	(134,804)		(135,914)
Taxes paid related to net share settlement of equity awards	(8,411)		(7,962)
Net cash provided by financing activities	579,937		1,056,228
Increase in cash and cash equivalents including restricted cash	79,000		739,862
Cash, cash equivalents, restricted cash, and restricted cash equivalents at beginning of period	932,933	[1]	999,045	[2]
Cash, cash equivalents, restricted cash, and restricted cash equivalents at end of period	1,011,933	[1]	1,738,907
Supplemental Cash Flow Information
Income tax payments, net	40,340		11,195
Interest paid	122,182		101,632
Non-cash Activities
Premises and equipment transferred to/(from) other assets	785		(3,387)
Loans foreclosed and transferred to other real estate	11,280		6,571
Loans transferred to/(from) other loans held for sale at fair value	4,088		77,774
Topic 606 cumulative-effect adjustment to opening balance of retained earnings	(685)		0
Equity investment securities available for sale transferred to other assets at fair value	3,162		0
Securities purchased during the period but settled after period-end	0		193,286
Dividends declared on common stock during the period but paid after period-end	$ 29,211		$ 17,990
[1]	See "Note 1 - Basis of Presentation" of this Report for information on Synovus' change in presentation of cash and cash equivalents.
[2]	See "Note 1 - Basis of Presentation" of this Report for information on Synovus' change in presentation of cash and cash equivalents.

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Basis of Presentation	Note 1 - Basis of Presentation General The accompanying unaudited interim consolidated financial statements of Synovus Financial Corp. include the accounts of the Parent Company and its consolidated subsidiaries. Synovus Financial Corp. is a financial services company based in Columbus, Georgia. Through its wholly-owned subsidiary, Synovus Bank, a Georgia state-chartered bank that is a member of the Federal Reserve System, the company provides commercial and retail banking in addition to a full suite of specialized products and services including private banking, treasury management, wealth management, premium finance and international banking. Synovus Bank is positioned in markets in the Southeast, with 249 branches and 334 ATMs in Georgia, Alabama, South Carolina, Florida, and Tennessee. The accompanying unaudited interim consolidated financial statements have been prepared in accordance with the instructions to the SEC Form 10-Q and Article 10 of Regulation S-X; therefore, they do not include all information and footnotes necessary for a fair presentation of financial position, results of operations, comprehensive income, and cash flows in conformity with GAAP. All adjustments consisting of normally recurring accruals that, in the opinion of management, are necessary for a fair presentation of the consolidated financial position and results of operations for the periods covered by this Report have been included. The accompanying unaudited interim consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes appearing in Synovus' 2017 Form 10-K . Reclassifications In connection with the adoption of ASU 2016-18, Statement of Cash Flows-Restricted Cash , Synovus changed its presentation of cash and cash equivalents, effective January 1, 2018, to include cash and due from banks as well as interest-bearing funds with Federal Reserve Bank, interest earning deposits with banks, and federal funds sold and securities purchased under resale agreements, which are inclusive of any restricted cash and restricted cash equivalents. Prior to 2018, cash and cash equivalents only included cash and due from banks. Prior periods have been revised to maintain comparability. Excluding the aforementioned presentation change and the recently adopted accounting standards listed below, there have been no significant changes to the accounting policies as disclosed in Synovus' 2017 Form 10-K . Prior periods' consolidated financial statements are reclassified whenever necessary to conform to the current periods' presentation. Use of Estimates in the Preparation of Financial Statements In preparing the unaudited interim consolidated financial statements in accordance with GAAP, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities as of the date of the respective consolidated balance sheets and the reported amounts of revenues and expenses for the periods presented. Actual results could differ from those estimates. Material estimates that are particularly susceptible to significant change relate to the determination of the allowance for loan losses and the fair value of investment securities. Recently Adopted Accounting Standards ASU 2014-09, Revenue from Contracts with Customers (Topic 606) issued by the FASB in May 2014 , and all subsequent ASUs that modified Topic 606. ASU 2014-09 implements a common revenue standard that establishes principles for reporting information about the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts to provide goods or services to customers. The core principle of the revenue model is that a company will recognize revenue when it transfers control of goods or services to customers at an amount that reflects the consideration to which it expects to be entitled in exchange for those goods or services. The scope of the guidance explicitly excludes net interest income as well as many other revenues from financial assets. Management reviewed its revenue streams and contracts with customers and did not identify material changes to the timing or amount of revenue recognition. Synovus adopted these ASUs on the required effective date of January 1, 2018 utilizing the modified retrospective method of adoption. The adoption resulted in a cumulative effect adjustment of ($685) thousand to the opening balance of retained earnings. Beginning January 1, 2018, in connection with the adoption of this standard, Synovus began including merchant discounts and other card-related fees in card fees. For periods prior to January 1, 2018, these amounts were previously presented in other non-interest income and have been reclassified for comparability. See "Part I - Item 1. Financial Statements and Supplementary Data - Note 12 - Non-interest Income" for the required disclosures in accordance with this ASU. ASU 2018-02, Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. In February 2018, the FASB issued final guidance on reclassification of tax effects stranded in other comprehensive income due to Federal Tax Reform. The guidance provides entities the option to reclassify the tax effects that are stranded in accumulated other comprehensive income, or AOCI, as a result of Federal Tax Reform to retained earnings. The guidance is effective for fiscal years beginning after December 15, 2018; early adoption is permitted. Synovus elected to early adopt ASU 2018-02 as of January 1, 2018 and elected to reclassify the income tax effects of Federal Tax Reform from AOCI to retained earnings. For Synovus, tax effects stranded in AOCI due to Federal Tax Reform totaled $7.6 million at December 31, 2017 and primarily related to unrealized losses on the available-for-sale investment securities portfolio. The reclassification adjustment resulted in an increase to retained earnings as of January 1, 2018 of $7.6 million and a corresponding decrease to AOCI for the same amount. ASU 2016-01, Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilitie s. In January 2016, the FASB issued ASU 2016-01, which included targeted amendments to accounting guidance for recognition, measurement, presentation, and disclosure of financial instruments. ASU 2016-01 requires equity investments (except those accounted for under the equity method of accounting or those that are consolidated) to be measured at fair value with changes in fair value recognized in net income. This ASU requires a cumulative-effect adjustment to retained earnings as of the beginning of the reporting period of adoption to reclassify the cumulative change in fair value of equity securities previously recognized in AOCI. ASU 2016-01 became effective for Synovus on January 1, 2018. The adoption of the guidance resulted in a transfer of investments in mutual funds of $3.2 million , at fair value, from investment securities available for sale to other assets and a $117 thousand cumulative-effect adjustment that decreased retained earnings, with offsetting related adjustments to deferred taxes and AOCI. ASU 2016-01 also emphasizes the existing requirement to use an exit price concept to measure fair value for disclosure purposes in determining the fair value of loans. Determination of the fair value under the exit price method requires judgment because substantially all of the loans within the loan portfolio do not have observable market prices. The adoption of this guidance did not have a significant impact on Synovus' fair value disclosures. ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement . In August 2018, the FASB issued ASU 2018-13, which changes the fair value measurement disclosure requirements of ASC 820. The amendments in this ASU remove, modify, and add certain required disclosures on fair value measurements. The guidance is effective for fiscal years beginning after December 15, 2019; early adoption is permitted. Synovus elected to early adopt ASU 2018-13 for eliminated and modified disclosures upon issuance of this ASU. Synovus will delay adoption of the additional disclosures until their effective date. The adoption of this guidance did not have a significant impact on Synovus' fair value disclosures. ASU 2018-15, Intangibles - Goodwill and Other - Internal Use Software (Subtopic 350-40): Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That is a Service Contract. In August 2018, the FASB issued ASU 2018-15, which amends ASC 350-40. The ASU aligns the requirements for capitalizing implementation costs for a hosting arrangement that is a service contract with those incurred for hosting arrangements that contain a software license as well as those incurred to develop or implement software for internal use. This guidance is effective for fiscal years beginning after December 15, 2019; early adoption is permitted. Synovus elected to early adopt ASU 2018-15, on a prospective basis, upon issuance of this ASU. As of September 30, 2018, no implementation costs have been capitalized under this ASU. Synovus expects to capitalize certain qualifying implementation, set-up, and other upfront costs related to hosting arrangements under a service contract during the fourth quarter of 2018. Recently Issued Accounting Standards Not Yet Adopted ASU 2016-13, Financial Instruments--Credit Losses (CECL). In June 2016, the FASB issued new guidance related to credit losses. The new guidance replaces the existing incurred loss impairment guidance with an expected credit loss methodology. The new guidance will require management’s estimate of credit losses over the full remaining expected life of loans and other financial instruments. For Synovus, the standard will apply to loans, unfunded loan commitments, and debt securities available for sale. The standard is effective for fiscal years beginning after December 15, 2019 and interim periods within those fiscal years with early adoption permitted on January 1, 2019. Synovus will adopt the guidance on January 1, 2020. Upon adoption, Synovus will record a cumulative-effect adjustment to retained earnings as of the beginning of the reporting period of adoption. Synovus has begun its implementation efforts which are led by a cross-functional steering committee. Management expects that the allowance for loan losses will be higher under the new standard; however, management is still in the process of determining the magnitude of the impact on its financial statements and regulatory capital ratios. Additionally, the extent of the expected increase on the allowance for loan losses will depend upon the composition of the loan portfolio upon adoption of the standard, as well as economic conditions and forecasts at that time. ASU 2016-02 , Leases (ASC 842) . In February 2016, the FASB issued ASU 2016-02, its new standard on lease accounting. ASU 2016-02 introduces a lessee model that brings most leases on the balance sheet. Under the new standard, all lessees will recognize a right-of-use asset and a lease liability, including operating leases, with a lease term greater than 12 months. From a lessor perspective, the accounting model is largely unchanged from existing GAAP. Additional amendments include, but are not limited to, the elimination of leveraged leases; modification to the definition of a lease; amendments on sale and leaseback transactions; and disclosure of additional qualitative and quantitative information. In July 2018, the FASB issued ASU 2018-11 , Leases (ASC 842), Targeted Improvements . The ASU 2018-11 amendments include an optional transition method to apply ASU 2016-02 on a prospective basis as of the effective date, with a cumulative- effect adjustment to retained earnings in the period of adoption, instead of applying the guidance using the modified retrospective approach as originally required under ASU 2016-02. ASU 2018-11 also provides lessors with a practical expedient, by class of underlying asset, to not separate lease and non-lease components under certain circumstances, and clarifies which guidance (ASC 842 or ASC 606) to apply to the combined lease and non-lease components. Synovus will elect the optional transition method provided through ASU 2018-11 and will adopt ASU 2016-02 prospectively on January 1, 2019. Synovus will elect the package of practical expedients to not reassess (a) whether existing contracts contain leases, (b) lease classification for existing leases, and (c) initial direct cost for any existing leases. Synovus currently expects to recognize lease liabilities and corresponding right-of-use assets (at their present value) related to substantially all of the $230 million of future minimum lease commitments as disclosed in Note 7 of Synovus' 2017 Form 10-K. Additionally, Synovus expects to recognize a cumulative-effect adjustment upon adoption to increase the beginning balance of retained earnings as of January 1, 2019 for any remaining deferred gains on sale-leaseback transactions that occurred prior to the date of initial application. Synovus had approximately $5.2 million of such deferred gains recorded as of September 30, 2018. Synovus does not expect this ASU to have a material impact on the timing of expense recognition in its consolidated statements of income.

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2018
Business Combinations [Abstract]
Acquisitions	Note 2 - Acquisitions Cabela's Transaction On September 25, 2017, Synovus' wholly owned subsidiary, Synovus Bank, completed the acquisition of certain assets and assumption of certain liabilities of WFB. Immediately following the closing of this transaction, Synovus Bank sold WFB’s credit card assets and related liabilities to Capital One Bank (USA), National Association, a bank subsidiary of Capital One Financial Corporation. Synovus retained WFB’s $1.10 billion brokered time deposits portfolio, which had a weighted average remaining maturity of approximately 2.53 years and a weighted average rate of 1.83% as of September 25, 2017. The transaction was accounted for as an assumption of a liability (accounted for under the asset acquisition model). In accordance with ASC 820, Fair Value Measurements and Disclosures, the brokered time deposit portfolio was recorded at $1.10 billion , which was the amount of cash received for the deposits and represented the estimated fair value of the deposits at the transaction date. Additionally, Synovus received a $75.0 million transaction fee from Cabela’s Incorporated and Capital One, which was recognized into earnings on September 25, 2017 upon closing of the transaction, based on having achieved the recognition criteria outlined in SEC SAB Topic 13.A, Revenue Recognition . Acquisition of Global One On October 1, 2016, Synovus completed its acquisition of all of the outstanding stock of Global One. Prior to its acquisition, Global One was an Atlanta-based private specialty financial services company that provided financing primarily to commercial entities, with all loans fully collateralized by cash value life insurance policies and/or annuities issued by investment grade life insurance companies. Under the terms of the merger agreement, Synovus acquired Global One for an up-front payment of $30 million , consisting of the issuance of 821 thousand shares of Synovus common stock valued at $26.6 million and $3.4 million in cash, with additional payments to Global One's former shareholders over a three to five year period based on earnings from the Global One business, as further discussed below. The acquisition of Global One constituted a business combination. Accordingly, the assets acquired and liabilities assumed were recorded at their estimated fair values on October 1, 2016. The determination of fair value required management to make estimates about discount rates, future expected earnings and cash flows, market conditions, future loan growth, and other future events that are highly subjective in nature and subject to change. During the three months ended September 30, 2017, Synovus completed the determination of the final allocation of the purchase price with respect to the assets acquired and liabilities assumed. Under the terms of the merger agreement, the purchase price includes additional annual payments ("Earnout Payments") to Global One's former shareholders over a three to five year period, with amounts based on a percentage of "Global One Earnings," as defined in the merger agreement. The Earnout Payments consist of shares of Synovus common stock as well as a smaller cash consideration component. The first annual Earnout Payment of stock and cash valued at $6.4 million was made during November 2017. During the quarter ended September 30, 2018, Synovus recorded an $11.7 million increase to the earnout liability driven by increased earnings projections of Global One. The total fair value of the earnout liability at September 30, 2018 was $23.0 million based on the estimated fair value of the remaining Earnout Payments.

Investment Securities Available

Investment Securities Available for Sale	9 Months Ended
	Sep. 30, 2018
Investments [Abstract]
Investment Securities Available for Sale	Note 3 - Investment Securities Available for Sale The amortized cost, gross unrealized gains and losses, and estimated fair values of investment securities available for sale at September 30, 2018 and December 31, 2017 are summarized below. September 30, 2018 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. Treasury securities $ 123,265 $ — $ (2,626 ) $ 120,639 U.S. Government agency securities 38,020 102 (258 ) 37,864 Mortgage-backed securities issued by U.S. Government agencies 104,933 75 (4,125 ) 100,883 Mortgage-backed securities issued by U.S. Government sponsored enterprises 2,592,827 70 (103,532 ) 2,489,365 Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises 1,168,378 — (50,675 ) 1,117,703 Corporate debt and other debt securities 17,000 155 (35 ) 17,120 Total investment securities available for sale $ 4,044,423 $ 402 $ (161,251 ) $ 3,883,574 December 31, 2017 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. Treasury securities $ 83,608 $ — $ (934 ) $ 82,674 U.S. Government agency securities 10,771 91 — 10,862 Mortgage-backed securities issued by U.S. Government agencies 121,283 519 (1,362 ) 120,440 Mortgage-backed securities issued by U.S. Government sponsored enterprises 2,666,818 5,059 (31,354 ) 2,640,523 Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises 1,135,259 144 (23,404 ) 1,111,999 State and municipal securities 180 — — 180 Corporate debt and other securities 20,320 294 (223 ) 20,391 Total investment securities available for sale $ 4,038,239 $ 6,107 $ (57,277 ) $ 3,987,069 At September 30, 2018 and December 31, 2017 , investment securities with a carrying value of $1.29 billion and $2.00 billion , respectively, were pledged to secure certain deposits and securities sold under repurchase agreements as required by law and contractual agreements. Synovus has reviewed investment securities that are in an unrealized loss position as of September 30, 2018 and December 31, 2017 for OTTI and does not consider any securities in an unrealized loss position to be other-than-temporarily impaired. If Synovus intended to sell a security in an unrealized loss position, the entire unrealized loss would be reflected in earnings. Synovus does not intend to sell investment securities in an unrealized loss position prior to the recovery of the unrealized loss, which may not be until maturity, and has the ability and intent to hold those securities for that period of time. Additionally, Synovus is not currently aware of any circumstances which will require it to sell any of the securities that are in an unrealized loss position prior to the respective securities' recovery of all such unrealized losses. For investment securities that Synovus does not expect to sell, or it is not more likely than not it will be required to sell prior to recovery of its amortized cost basis, the credit component of an OTTI would be recognized in earnings and the non-credit component would be recognized in OCI. Currently, unrealized losses on debt securities are attributable to increases in interest rates on comparable securities from the date of purchase. Synovus regularly evaluates its investment securities portfolio to ensure that there are no conditions that would indicate that unrealized losses represent OTTI. These factors include the length of time the security has been in a loss position, the extent that the fair value is below amortized cost, and the credit standing of the issuer. As of September 30, 2018 , Synovus had 43 investment securities in a loss position for less than twelve months and 100 investment securities in a loss position for twelve months or longer. Gross unrealized losses on investment securities and the fair value of the related securities, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position, at September 30, 2018 and December 31, 2017 are presented below. September 30, 2018 Less than 12 Months 12 Months or Longer Total (in thousands) Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses U.S. Treasury securities $ 38,352 $ 739 $ 62,905 $ 1,887 $ 101,257 $ 2,626 U.S. Government agency securities 29,727 258 — — 29,727 258 Mortgage-backed securities issued by U.S. Government agencies 15,655 364 73,555 3,761 89,210 4,125 Mortgage-backed securities issued by U.S. Government sponsored enterprises 830,455 24,765 1,618,843 78,767 2,449,298 103,532 Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises 214,420 3,406 903,283 47,269 1,117,703 50,675 Corporate debt and other debt securities — — 1,965 35 1,965 35 Total $ 1,128,609 $ 29,532 $ 2,660,551 $ 131,719 $ 3,789,160 $ 161,251 December 31, 2017 Less than 12 Months 12 Months or Longer Total (in thousands) Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses U.S. Treasury securities $ 34,243 $ 443 $ 29,562 $ 491 $ 63,805 $ 934 Mortgage-backed securities issued by U.S. Government agencies 36,810 357 55,740 1,005 92,550 1,362 Mortgage-backed securities issued by U.S. Government sponsored enterprises 1,271,012 10,263 929,223 21,091 2,200,235 31,354 Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises 653,781 9,497 426,237 13,907 1,080,018 23,404 Corporate debt and other securities — — 5,097 223 5,097 223 Total $ 1,995,846 $ 20,560 $ 1,445,859 $ 36,717 $ 3,441,705 $ 57,277 The amortized cost and fair value by contractual maturity of investment securities available for sale at September 30, 2018 are shown below. The expected life of mortgage-backed securities or CMOs may differ from contractual maturities because issuers may have the right to call or prepay obligations with or without call or prepayment penalties. For purposes of the maturity table, mortgage-backed securities and CMOs, which are not due at a single maturity date, have been classified based on the final contractual maturity date. Distribution of Maturities at September 30, 2018 (in thousands) Within One 1 to 5 5 to 10 More Than Total Amortized Cost U.S. Treasury securities $ 19,382 $ 103,883 $ — $ — $ 123,265 U.S. Government agency securities 1,917 6,118 29,985 — 38,020 Mortgage-backed securities issued by U.S. Government agencies — — 25,659 79,274 104,933 Mortgage-backed securities issued by U.S. Government sponsored enterprises — 43,496 556,115 1,993,216 2,592,827 Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises — — 28,367 1,140,011 1,168,378 Corporate debt and other debt securities — — 15,000 2,000 17,000 Total amortized cost $ 21,299 $ 153,497 $ 655,126 $ 3,214,501 $ 4,044,423 Fair Value U.S. Treasury securities $ 19,382 $ 101,257 $ — $ — $ 120,639 U.S. Government agency securities 1,937 6,200 29,727 — 37,864 Mortgage-backed securities issued by U.S. Government agencies — — 25,154 75,729 100,883 Mortgage-backed securities issued by U.S. Government sponsored enterprises — 42,630 534,881 1,911,854 2,489,365 Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises — — 27,198 1,090,505 1,117,703 Corporate debt and other debt securities — — 15,155 1,965 17,120 Total fair value $ 21,319 $ 150,087 $ 632,115 $ 3,080,053 $ 3,883,574 Proceeds from sales, gross gains, and gross losses on sales of securities available for sale for the three and nine months ended September 30, 2018 and 2017 are presented below. The specific identification method is used to reclassify gains and losses out of other comprehensive income at the time of sale. On January 1, 2018, Synovus transferred $3.2 million , at fair value, from investment securities available for sale to other assets upon adoption of ASU 2016-01. Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Proceeds from sales of investment securities available for sale $ — $ 473,912 $ 35,066 $ 812,293 Gross realized gains on sales — — — 7,942 Gross realized losses on sales — (7,956 ) (1,296 ) (8,231 ) Investment securities losses, net $ — $ (7,956 ) $ (1,296 ) $ (289 )

Loans and Allowance for Loan Lo

Loans and Allowance for Loan Losses	9 Months Ended
	Sep. 30, 2018
Loans and Allowance for Loan Losses [Abstract]
Loans and Allowance for Loan Losses	Note 4 - Loans and Allowance for Loan Losses The following is a summary of current, accruing past due, and non-accrual loans by portfolio class as of September 30, 2018 and December 31, 2017 . Current, Accruing Past Due, and Non-accrual Loans September 30, 2018 (in thousands) Current Accruing 30-89 Days Past Due Accruing 90 Days or Greater Past Due Total Accruing Past Due Non-accrual Total Commercial, financial and agricultural $ 7,185,447 $ 25,850 $ 1,159 $ 27,009 $ 69,010 $ 7,281,466 Owner-occupied 5,206,192 8,879 1,049 9,928 5,708 5,221,828 Total commercial and industrial 12,391,639 34,729 2,208 36,937 74,718 12,503,294 Investment properties 5,661,605 1,930 — 1,930 2,155 5,665,690 1-4 family properties 701,406 2,651 — 2,651 3,139 707,196 Land and development 333,709 765 217 982 4,829 339,520 Total commercial real estate 6,696,720 5,346 217 5,563 10,123 6,712,406 Home equity lines 1,442,451 7,819 651 8,470 14,498 1,465,419 Consumer mortgages 2,832,971 4,960 — 4,960 5,313 2,843,244 Credit cards 241,334 2,170 1,645 3,815 — 245,149 Other consumer loans 1,809,033 18,444 135 18,579 3,773 1,831,385 Total consumer 6,325,789 33,393 2,431 35,824 23,584 6,385,197 Total loans $ 25,414,148 $ 73,468 $ 4,856 $ 78,324 $ 108,425 $ 25,600,897 (1 ) December 31, 2017 (in thousands) Current Accruing 30-89 Days Past Due Accruing 90 Days or Greater Past Due Total Accruing Past Due Non-accrual Total Commercial, financial and agricultural $ 7,097,127 $ 11,214 $ 1,016 $ 12,230 $ 70,130 $ 7,179,487 Owner-occupied 4,830,150 6,880 479 7,359 6,654 4,844,163 Total commercial and industrial 11,927,277 18,094 1,495 19,589 76,784 12,023,650 Investment properties 5,663,665 2,506 90 2,596 3,804 5,670,065 1-4 family properties 775,023 3,545 202 3,747 2,849 781,619 Land and development 476,131 1,609 67 1,676 5,797 483,604 Total commercial real estate 6,914,819 7,660 359 8,019 12,450 6,935,288 Home equity lines 1,490,808 5,629 335 5,964 17,455 1,514,227 Consumer mortgages 2,622,061 3,971 268 4,239 7,203 2,633,503 Credit cards 229,015 1,930 1,731 3,661 — 232,676 Other consumer loans 1,461,223 10,333 226 10,559 1,669 1,473,451 Total consumer 5,803,107 21,863 2,560 24,423 26,327 5,853,857 Total loans $ 24,645,203 $ 47,617 $ 4,414 $ 52,031 $ 115,561 $ 24,812,795 (2 ) (1) Total before net deferred fees and costs of $23.8 million . (2) Total before net deferred fees and costs of $25.3 million . Loans with carrying values of $8.11 billion and $7.93 billion were pledged as collateral for borrowings and potential borrowings at September 30, 2018 and December 31, 2017 , respectively, to the FHLB and Federal Reserve Bank. The credit quality of the loan portfolio is reviewed and updated no less frequently than quarterly using the standard asset classification system utilized by the federal banking agencies. These classifications are divided into three groups – Not Criticized (Pass), Special Mention, and Classified or Adverse rating (Substandard, Doubtful, and Loss) and are defined as follows: Pass - loans which are well protected by the current net worth and paying capacity of the obligor (or guarantors, if any) or by the fair value, less cost to acquire and sell in a timely manner, of any underlying collateral. Special Mention - loans which have potential weaknesses that deserve management's close attention. These loans are not adversely classified and do not expose an institution to sufficient risk to warrant an adverse classification. Substandard - loans which are inadequately protected by the current net worth and paying capacity of the obligor or by the collateral pledged, if any. Loans with this classification are characterized by the distinct possibility that the institution will sustain some loss if the deficiencies are not corrected. Doubtful - loans which have all the weaknesses inherent in loans classified as Substandard with the added characteristic that the weaknesses make collection or liquidation in full highly questionable and improbable on the basis of currently known facts, conditions, and values. Loss - loans which are considered by management to be uncollectible and of such little value that their continuance on the institution's books as an asset, without establishment of a specific valuation allowance or charge-off, is not warranted. Synovus fully reserves for any loans rated as Loss. In the following tables, consumer loans are generally assigned a risk grade similar to the classifications described above; however, upon reaching 90 days and 120 days past due, they are generally downgraded to Substandard and Loss, respectively, in accordance with the FFIEC Uniform Retail Credit Classification and Account Management Policy. Additionally, in accordance with the Interagency Supervisory Guidance on Allowance for Loan and Lease Losses Estimation Practices for Loans and Lines of Credit Secured by Junior Liens on 1-4 Family Residential Properties, the risk grade classifications of home equity lines and consumer mortgages secured by junior liens on 1-4 family residential properties also consider available information on the payment status of any associated senior liens with other financial institutions. Loan Portfolio Credit Exposure by Risk Grade September 30, 2018 (in thousands) Pass Special Substandard (1) Doubtful (2) Loss Total Commercial, financial and agricultural $ 6,986,930 $ 135,359 $ 157,922 $ 1,251 $ 4 (3) $ 7,281,466 Owner-occupied 5,077,397 79,967 64,038 426 — 5,221,828 Total commercial and industrial 12,064,327 215,326 221,960 1,677 4 12,503,294 Investment properties 5,587,389 47,667 30,634 — — 5,665,690 1-4 family properties 687,775 7,943 11,478 — — 707,196 Land and development 298,696 24,661 12,689 3,129 345 (3) 339,520 Total commercial real estate 6,573,860 80,271 54,801 3,129 345 6,712,406 Home equity lines 1,446,606 — 17,513 175 1,125 (3) 1,465,419 Consumer mortgages 2,836,972 — 6,171 101 — 2,843,244 Credit cards 243,503 — 570 — 1,076 (4) 245,149 Other consumer loans 1,827,487 — 3,640 257 1 (3) 1,831,385 Total consumer 6,354,568 — 27,894 533 2,202 6,385,197 Total loans $ 24,992,755 $ 295,597 $ 304,655 $ 5,339 $ 2,551 $ 25,600,897 (5 ) December 31, 2017 (in thousands) Pass Special Substandard (1) Doubtful (2) Loss Total Commercial, financial and agricultural $ 6,929,506 $ 115,912 $ 132,818 $ 1,251 $ — $ 7,179,487 Owner-occupied 4,713,877 50,140 80,073 73 — 4,844,163 Total commercial and industrial 11,643,383 166,052 212,891 1,324 — 12,023,650 Investment properties 5,586,792 64,628 18,645 — — 5,670,065 1-4 family properties 745,299 19,419 16,901 — — 781,619 Land and development 431,759 33,766 14,950 3,129 — 483,604 Total commercial real estate 6,763,850 117,813 50,496 3,129 — 6,935,288 Home equity lines 1,491,105 — 21,079 285 1,758 (3) 1,514,227 Consumer mortgages 2,622,499 — 10,607 291 106 (3) 2,633,503 Credit cards 230,945 — 399 — 1,332 (4) 232,676 Other consumer loans 1,470,944 — 2,168 329 10 (3) 1,473,451 Total consumer 5,815,493 — 34,253 905 3,206 5,853,857 Total loans $ 24,222,726 $ 283,865 $ 297,640 $ 5,358 $ 3,206 $ 24,812,795 (6 ) (1) Includes $204.1 million and $190.6 million of Substandard accruing loans at September 30, 2018 and December 31, 2017 , respectively. (2) The loans within this risk grade are on non-accrual status. Commercial loans generally have an allowance for loan losses in accordance with ASC 310, and retail loans generally have an allowance for loan losses equal to 50% of the loan amount. (3) The loans within this risk grade are on non-accrual status and have an allowance for loan losses equal to the full loan amount. (4) Represent amounts that were 120 days past due. These credits are downgraded to the Loss category with an allowance for loan losses equal to the full loan amount and are generally charged off upon reaching 181 days past due in accordance with the FFIEC Uniform Retail Credit Classification and Account Management Policy. (5) Total before net deferred fees and costs of $23.8 million . (6) Total before net deferred fees and costs of $25.3 million . The following table details the changes in the allowance for loan losses by loan segment for the three and nine months ended September 30, 2018 and 2017 . Allowance for Loan Losses and Recorded Investment in Loans As Of and For The Three Months Ended September 30, 2018 (in thousands) Commercial & Industrial Commercial Real Estate Consumer Total Allowance for loan losses: Beginning balance $ 130,335 $ 75,205 $ 46,185 $ 251,725 Charge-offs (13,526 ) (1,077 ) (3,993 ) (18,596 ) Recoveries 1,091 591 1,657 3,339 Provision for loan losses 11,417 (1,447 ) 5,012 14,982 Ending balance (1) $ 129,317 $ 73,272 $ 48,861 $ 251,450 Ending balance: individually evaluated for impairment $ 9,108 $ 3,317 $ 970 $ 13,395 Ending balance: collectively evaluated for impairment $ 120,209 $ 69,955 $ 47,891 $ 238,055 Loans: Ending balance: total loans (1)(2) $ 12,503,294 $ 6,712,406 $ 6,385,197 $ 25,600,897 Ending balance: individually evaluated for impairment $ 102,671 $ 37,988 $ 28,963 $ 169,622 Ending balance: collectively evaluated for impairment $ 12,400,623 $ 6,674,418 $ 6,356,234 $ 25,431,275 As Of and For The Three Months Ended September 30, 2017 (in thousands) Commercial & Industrial Commercial Real Estate Consumer Total Allowance for loan losses: Beginning balance $ 123,437 $ 77,527 $ 47,131 $ 248,095 Charge-offs (21,855 ) (8,129 ) (14,367 ) (44,351 ) Recoveries 1,899 2,543 1,811 6,253 Provision for loan losses 23,022 6,019 10,645 39,686 Ending balance (1) $ 126,503 $ 77,960 $ 45,220 $ 249,683 Ending balance: individually evaluated for impairment $ 7,360 $ 4,108 $ 783 $ 12,251 Ending balance: collectively evaluated for impairment $ 119,143 $ 73,852 $ 44,437 $ 237,432 Loans: Ending balance: total loans (1)(3) $ 11,727,142 $ 7,226,924 $ 5,557,572 $ 24,511,638 Ending balance: individually evaluated for impairment $ 109,434 $ 64,909 $ 30,132 $ 204,475 Ending balance: collectively evaluated for impairment $ 11,617,708 $ 7,162,015 $ 5,527,440 $ 24,307,163 (1) As of and for the three months ended September 30, 2018 and 2017 , there were no purchased credit-impaired loans and no allowance for loan losses for purchased credit-impaired loans. (2) Total before net deferred fees and costs of $23.8 million . (3) Total before net deferred fees and costs of $24.3 million . Allowance for Loan Losses and Recorded Investment in Loans As Of and For The Nine Months Ended September 30, 2018 (in thousands) Commercial & Industrial Commercial Real Estate Consumer Total Allowance for loan losses: Beginning balance $ 126,803 $ 74,998 $ 47,467 $ 249,268 Charge-offs (37,312 ) (3,523 ) (13,888 ) (54,723 ) Recoveries 5,086 7,555 4,716 17,357 Provision for loan losses 34,740 (5,758 ) 10,566 39,548 Ending balance (1) $ 129,317 $ 73,272 $ 48,861 $ 251,450 Ending balance: individually evaluated for impairment $ 9,108 $ 3,317 $ 970 $ 13,395 Ending balance: collectively evaluated for impairment $ 120,209 $ 69,955 $ 47,891 $ 238,055 Loans: Ending balance: total loans (1)(2) $ 12,503,294 $ 6,712,406 $ 6,385,197 $ 25,600,897 Ending balance: individually evaluated for impairment $ 102,671 $ 37,988 $ 28,963 $ 169,622 Ending balance: collectively evaluated for impairment $ 12,400,623 $ 6,674,418 $ 6,356,234 $ 25,431,275 As Of and For The Nine Months Ended September 30, 2017 (in thousands) Commercial & Industrial Commercial Real Estate Consumer Total Allowance for loan losses: Beginning balance $ 125,778 $ 81,816 $ 44,164 $ 251,758 Charge-offs (41,390 ) (11,336 ) (24,023 ) (76,749 ) Recoveries 5,181 6,191 4,682 16,054 Provision for loan losses 36,934 1,289 20,397 58,620 Ending balance (1) $ 126,503 $ 77,960 $ 45,220 $ 249,683 Ending balance: individually evaluated for impairment $ 7,360 $ 4,108 $ 783 $ 12,251 Ending balance: collectively evaluated for impairment $ 119,143 $ 73,852 $ 44,437 $ 237,432 Loans: Ending balance: total loans (1)(3) $ 11,727,142 $ 7,226,924 $ 5,557,572 $ 24,511,638 Ending balance: individually evaluated for impairment $ 109,434 $ 64,909 $ 30,132 $ 204,475 Ending balance: collectively evaluated for impairment $ 11,617,708 $ 7,162,015 $ 5,527,440 $ 24,307,163 (1) As of and for the nine months ended September 30, 2018 and 2017 , there were no purchased credit-impaired loans and no allowance for loan losses for purchased credit-impaired loans. (2) Total before net deferred fees and costs of $23.8 million . (3) Total before net deferred fees and costs of $24.3 million . The tables below summarize impaired loans (including accruing TDRs) as of September 30, 2018 and December 31, 2017 . Impaired Loans (including accruing TDRs) September 30, 2018 Three Months Ended September 30, 2018 Nine Months Ended September 30, 2018 (in thousands) Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized With no related allowance recorded Commercial, financial and agricultural $ 20,884 $ 26,878 $ — $ 21,118 $ — $ 14,458 $ — Owner-occupied — — — — — — — Total commercial and industrial 20,884 26,878 — 21,118 — 14,458 — Investment properties — — — — — — — 1-4 family properties — — — — — — — Land and development 265 1,110 — 88 — 42 — Total commercial real estate 265 1,110 — 88 — 42 — Home equity lines — — — — — 949 — Consumer mortgages 33 60 — 42 — 901 — Credit cards — — — — — — — Other consumer loans — — — — — — — Total consumer 33 60 — 42 — 1,850 — Total impaired loans with no related allowance recorded $ 21,182 $ 28,048 $ — $ 21,248 $ — $ 16,350 $ — With allowance recorded Commercial, financial and agricultural $ 35,181 $ 36,127 $ 6,024 $ 40,136 $ 143 $ 55,088 $ 571 Owner-occupied 46,606 47,292 3,084 44,366 435 40,171 1,165 Total commercial and industrial 81,787 83,419 9,108 84,502 578 95,259 1,736 Investment properties 13,846 13,846 1,566 14,103 179 20,437 597 1-4 family properties 8,307 8,307 191 9,697 176 10,876 619 Land and development 15,570 17,311 1,560 16,734 61 17,765 211 Total commercial real estate 37,723 39,464 3,317 40,534 416 49,078 1,427 Home equity lines 3,209 3,223 236 3,433 20 3,693 96 Consumer mortgages 20,201 20,201 575 19,924 225 19,496 618 Credit cards — — — — — — — Other consumer loans 5,520 5,520 159 5,284 69 5,220 212 Total consumer 28,930 28,944 970 28,641 314 28,409 926 Total impaired loans with allowance recorded $ 148,440 $ 151,827 $ 13,395 $ 153,677 $ 1,308 $ 172,746 $ 4,089 Total impaired loans Commercial, financial and agricultural $ 56,065 $ 63,005 $ 6,024 $ 61,254 $ 143 $ 69,546 $ 571 Owner-occupied 46,606 47,292 3,084 44,366 435 40,171 1,165 Total commercial and industrial 102,671 110,297 9,108 105,620 578 109,717 1,736 Investment properties 13,846 13,846 1,566 14,103 179 20,437 597 1-4 family properties 8,307 8,307 191 9,697 176 10,876 619 Land and development 15,835 18,421 1,560 16,822 61 17,807 211 Total commercial real estate 37,988 40,574 3,317 40,622 416 49,120 1,427 Home equity lines 3,209 3,223 236 3,433 20 4,642 96 Consumer mortgages 20,234 20,261 575 19,966 225 20,397 618 Credit cards — — — — — — — Other consumer loans 5,520 5,520 159 5,284 69 5,220 212 Total consumer 28,963 29,004 970 28,683 314 30,259 926 Total impaired loans $ 169,622 $ 179,875 $ 13,395 $ 174,925 $ 1,308 $ 189,096 $ 4,089 Impaired Loans (including accruing TDRs) December 31, 2017 Year Ended December 31, 2017 (in thousands) Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized With no related allowance recorded Commercial, financial and agricultural $ 8,220 $ 9,576 $ — $ 21,686 $ — Owner-occupied — — — 6,665 — Total commercial and industrial 8,220 9,576 — 28,351 — Investment properties — — — 123 — 1-4 family properties — — — 323 — Land and development 56 1,740 — 1,816 — Total commercial real estate 56 1,740 — 2,262 — Home equity lines 2,746 2,943 — 1,205 — Consumer mortgages — — — 496 — Credit cards — — — — — Other consumer loans — — — — — Total consumer 2,746 2,943 — 1,701 — Total impaired loans with no related allowance recorded $ 11,022 $ 14,259 $ — $ 32,314 $ — With allowance recorded Commercial, financial and agricultural $ 65,715 $ 65,851 $ 7,406 $ 50,468 $ 1,610 Owner-occupied 37,399 37,441 2,109 40,498 1,382 Total commercial and industrial 103,114 103,292 9,515 90,966 2,992 Investment properties 23,364 23,364 1,100 28,749 1,144 1-4 family properties 15,056 15,056 504 16,257 925 Land and development 18,420 18,476 2,636 23,338 404 Total commercial real estate 56,840 56,896 4,240 68,344 2,473 Home equity lines 5,096 5,096 114 7,476 334 Consumer mortgages 18,668 18,668 569 19,144 896 Credit cards — — — — — Other consumer loans 5,546 5,546 470 4,765 266 Total consumer 29,310 29,310 1,153 31,385 1,496 Total impaired loans with allowance recorded $ 189,264 $ 189,498 $ 14,908 $ 190,695 $ 6,961 Total impaired loans Commercial, financial and agricultural $ 73,935 $ 75,427 $ 7,406 $ 72,154 $ 1,610 Owner-occupied 37,399 37,441 2,109 47,163 1,382 Total commercial and industrial 111,334 112,868 9,515 119,317 2,992 Investment properties 23,364 23,364 1,100 28,872 1,144 1-4 family properties 15,056 15,056 504 16,580 925 Land and development 18,476 20,216 2,636 25,154 404 Total commercial real estate 56,896 58,636 4,240 70,606 2,473 Home equity lines 7,842 8,039 114 8,681 334 Consumer mortgages 18,668 18,668 569 19,640 896 Credit cards — — — — — Other consumer loans 5,546 5,546 470 4,765 266 Total consumer 32,056 32,253 1,153 33,086 1,496 Total impaired loans $ 200,286 $ 203,757 $ 14,908 $ 223,009 $ 6,961 The average recorded investment in impaired loans was $218.7 million and $228.9 million respectively for the three and nine months ended September 30, 2017. Excluding accruing TDRs, there was no interest income recognized for the investment in impaired loans for the three and nine months ended September 30, 2017. Interest income recognized for accruing TDRs was $1.7 million and $5.2 million respectively for the three and nine months ended September 30, 2017. At September 30, 2018 and December 31, 2017 , impaired loans of $54.9 million and $49.0 million , respectively, were on non-accrual status. Concessions provided in a TDR are primarily in the form of providing a below market interest rate given the borrower's credit risk, a period of time generally less than one year with a reduction of required principal and/or interest payments (e.g., interest only for a period of time), or an extension of the maturity of the loan generally for less than one year. Insignificant periods of reduction of principal and/or interest payments, or one-time deferrals of 3 months or less, are generally not considered to be financial concessions. As of September 30, 2018 and December 31, 2017, there were no commitments to lend a material amount of additional funds to any customer whose loan was classified as a troubled debt restructuring. The following tables represent, by concession type, the post-modification balance for loans modified or renewed during the three and nine months ended September 30, 2018 and 2017 that were reported as accruing or non-accruing TDRs. TDRs by Concession Type Three Months Ended September 30, 2018 (in thousands, except contract data) Number of Contracts Principal Forgiveness Below Market Interest Rate Term Extensions and/or Other Concessions Total Commercial, financial and agricultural 7 $ — $ — $ 565 $ 565 Owner-occupied 3 — 727 4,839 5,566 Total commercial and industrial 10 — 727 5,404 6,131 Investment properties 1 — 42 — 42 1-4 family properties 5 — 445 766 1,211 Land and development 1 — — 71 71 Total commercial real estate 7 — 487 837 1,324 Home equity lines 1 — — 191 191 Consumer mortgages 2 — 670 — 670 Credit cards — — — — — Other consumer loans 44 — 695 2,784 3,479 Total consumer 47 — 1,365 2,975 4,340 Total TDRs 64 $ — $ 2,579 $ 9,216 $ 11,795 (1 ) Nine Months Ended September 30, 2018 (in thousands, except contract data) Number of Contracts Principal Forgiveness Below Market Interest Rate Term Extensions and/or Other Concessions Total Commercial, financial and agricultural 21 $ — $ — $ 2,130 $ 2,130 Owner-occupied 9 — 5,526 5,523 11,049 Total commercial and industrial 30 — 5,526 7,653 13,179 Investment properties 4 — 6,053 2,215 8,268 1-4 family properties 12 — 1,408 1,259 2,667 Land and development 4 — — 1,856 1,856 Total commercial real estate 20 — 7,461 5,330 12,791 Home equity lines 4 — 172 339 511 Consumer mortgages 16 — 5,365 87 5,452 Credit cards — — — — — Other consumer loans 75 — 1,621 3,606 5,227 Total consumer 95 — 7,158 4,032 11,190 Total TDRs 145 $ — $ 20,145 $ 17,015 $ 37,160 (1 ) (1) Net charge-offs of $88 thousand were recorded during both the three and nine months ended September 30, 2018 upon restructuring of these loans. TDRs by Concession Type Three Months Ended September 30, 2017 (in thousands, except contract data) Number of Contracts Principal Forgiveness Below Market Interest Rate Term Extensions and/or Other Concessions Total Commercial, financial and agricultural 22 $ — $ 2,943 $ 5,866 $ 8,809 Owner-occupied 3 — 35 1,683 1,718 Total commercial and industrial 25 — 2,978 7,549 10,527 Investment properties — — — — — 1-4 family properties 5 — — 964 964 Land and development 3 — 157 760 917 Total commercial real estate 8 — 157 1,724 1,881 Home equity lines — — — — — Consumer mortgages 7 — 248 1,181 1,429 Credit cards — — — — — Other consumer loans 17 — 682 388 1,070 Total consumer 24 — 930 1,569 2,499 Total TDRs 57 $ — $ 4,065 $ 10,842 $ 14,907 (2 ) Nine Months Ended September 30, 2017 (in thousands, except contract data) Number of Contracts Principal Forgiveness Below Market Interest Rate Term Extensions and/or Other Concessions Total Commercial, financial and agricultural 50 $ — $ 8,703 $ 12,145 $ 20,848 Owner-occupied 4 — 35 1,705 1,740 Total commercial and industrial 54 — 8,738 13,850 22,588 Investment properties — — — — — 1-4 family properties 21 — 2,090 1,477 3,567 Land and development 4 — 157 895 1,052 Total commercial real estate 25 — 2,247 2,372 4,619 Home equity lines — — — — — Consumer mortgages 8 — 248 1,190 1,438 Credit cards — — — — — Other consumer loans 25 — 682 958 1,640 Total consumer 33 — 930 2,148 3,078 Total TDRs 112 $ — $ 11,915 $ 18,370 $ 30,285 (2 ) (2) No net charge-offs were recorded during the three and nine months ended September 30, 2017 upon restructuring of these loans. For the three months ended September 30, 2018 there were no defaults, and for the nine months ended September 30, 2018 , there were eight defaults with a recorded investment of $10.5 million on accruing TDRs restructured during the previous twelve months (defaults are defined as the earlier of the TDR being placed on non-accrual status or reaching 90 days past due with respect to principal and/or interest payments) compared to one default with a recorded investment of $206 thousand and four defaults with a recorded investment of $498 thousand for the three and nine months ended September 30, 2017 , respectively. If, at the time a loan was designated as a TDR, the loan was not already impaired, the measurement of impairment that resulted from the TDR designation closely approximates the reserve derived through specific loan measurement of impairment in accordance with ASC 310-10-35. Generally, the change in the allowance for loan losses resulting from such TDR designation is not significant. At September 30, 2018 , the allowance for loan losses allocated to accruing TDRs totaling $114.7 million was $6.9 million compared to accruing TDRs of $151.3 million with an allocated allowance for loan losses of $8.7 million at December 31, 2017 . Non-accrual, non-homogeneous loans (commercial-type impaired loans greater than $1 million ) that are designated as TDRs are individually measured for the amount of impairment, if any, both before and after the TDR designation.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Accumulated Other Comprehensive Income (Loss)	Note 5 - Accumulated Other Comprehensive Income (Loss) The following tables illustrate activity within the balances in accumulated other comprehensive income (loss) by component for the three and nine months ended September 30, 2018 and 2017 . Changes in Accumulated Other Comprehensive Income (Loss) by Component (Net of Income Taxes) (in thousands) Net unrealized losses on cash flow hedges Net unrealized gains (losses) on investment securities available for sale Post-retirement unfunded health benefit Total Balance as of July 1, 2018 $ (12,137 ) $ (114,565 ) $ 982 $ (125,720 ) Other comprehensive loss before reclassifications — (17,940 ) (34 ) (17,974 ) Amounts reclassified from accumulated other comprehensive income (loss) — — (26 ) (26 ) Net current period other comprehensive loss — (17,940 ) (60 ) (18,000 ) Balance as of September 30, 2018 $ (12,137 ) $ (132,505 ) $ 922 $ (143,720 ) Balance as of July 1, 2017 $ (12,137 ) $ (36,586 ) $ 858 $ (47,865 ) Other comprehensive income before reclassifications — 3,359 38 3,397 Amounts reclassified from accumulated other comprehensive income (loss) — 4,893 (21 ) 4,872 Net current period other comprehensive income — 8,252 17 8,269 Balance as of September 30, 2017 $ (12,137 ) $ (28,334 ) $ 875 $ (39,596 ) (in thousands) Net unrealized gains (losses) on cash flow hedges Net unrealized gains (losses) on investment securities available for sale Post-retirement unfunded health benefit Total Balance at December 31, 2017 $ (12,137 ) $ (43,470 ) $ 853 $ (54,754 ) Other comprehensive loss before reclassifications — (82,349 ) (34 ) (82,383 ) Amounts reclassified from accumulated other comprehensive income (loss) — 960 (72 ) 888 Net current period other comprehensive loss — (81,389 ) (106 ) (81,495 ) Reclassification from adoption of ASU 2018-02 — (7,763 ) 175 (7,588 ) Cumulative-effect adjustment from adoption of ASU 2016-01 — 117 — 117 Balance as of September 30, 2018 $ (12,137 ) $ (132,505 ) $ 922 $ (143,720 ) Balance at December 31, 2016 $ (12,217 ) $ (44,324 ) $ 882 $ (55,659 ) Other comprehensive income before reclassifications — 15,812 38 15,850 Amounts reclassified from accumulated other comprehensive income (loss) 80 178 (45 ) 213 Net current period other comprehensive income 80 15,990 (7 ) 16,063 Balance as of September 30, 2017 $ (12,137 ) $ (28,334 ) $ 875 $ (39,596 ) In accordance with ASC 740-20-45-11(b), a deferred tax asset valuation allowance associated with unrealized gains and losses not recognized in income is charged directly to other comprehensive income (loss). During the years 2010 and 2011, Synovus recorded a deferred tax asset valuation allowance associated with net unrealized losses not recognized in income directly to other comprehensive income (loss) by applying the portfolio approach for allocation of the valuation allowance. Synovus has consistently applied the portfolio approach which treats derivative instruments and available for sale securities as a single portfolio. As of September 30, 2018 , the ending balance in net unrealized gains (losses) on cash flow hedges and net unrealized gains (losses) on investment securities available for sale includes unrealized losses of $12.1 million and $13.3 million , respectively, related to the residual tax effects remaining in OCI due to the previously established deferred tax asset valuation allowance. Under the portfolio approach, these unrealized losses are realized at the time the entire portfolio is sold or disposed.

Fair Value Accounting

Fair Value Accounting	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value Accounting	Note 6 - Fair Value Accounting See "Part II - Item 8. Financial Statements and Supplementary Data - Note 15 - Fair Value Accounting" to the consolidated financial statements of Synovus' 2017 Form 10-K for a description of the fair value hierarchy and valuation methodologies for assets and liabilities measured at fair value on a recurring and non-recurring basis. Assets and Liabilities Measured at Fair Value on a Recurring Basis The following tables present all financial instruments measured at fair value on a recurring basis as of September 30, 2018 and December 31, 2017 . September 30, 2018 (in thousands) Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Assets and Liabilities at Fair Value Assets Trading securities: U.S. Government agency securities $ — $ 6,532 $ — $ 6,532 Mortgage-backed securities issued by U.S. Government agencies — 921 — 921 Collateralized mortgage obligations issued by U.S. Government sponsored enterprises — 183 — 183 State and municipal securities — 177 — 177 Other investments 998 38 — 1,036 Total trading securities $ 998 $ 7,851 $ — $ 8,849 Mortgage loans held for sale — 37,276 — 37,276 Investment securities available for sale: U.S. Treasury securities $ 120,639 $ — $ — $ 120,639 U.S. Government agency securities — 37,864 — 37,864 Mortgage-backed securities issued by U.S. Government agencies — 100,883 — 100,883 Mortgage-backed securities issued by U.S. Government sponsored enterprises — 2,489,365 — 2,489,365 Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises — 1,117,703 — 1,117,703 Corporate debt and other debt securities — 15,155 1,965 17,120 Total investment securities available for sale $ 120,639 $ 3,760,970 $ 1,965 $ 3,883,574 Private equity investments — — 13,112 13,112 Mutual funds 3,118 — — 3,118 Mutual funds held in rabbi trusts 14,100 — — 14,100 GGL/SBA loans servicing asset — — 3,761 3,761 Derivative assets: Interest rate contracts $ — $ 8,892 $ — $ 8,892 Mortgage derivatives (1) — 1,122 — 1,122 Total derivative assets $ — $ 10,014 $ — $ 10,014 Liabilities Trading account liabilities — 3,540 — 3,540 Earnout liability (2) — — 23,000 23,000 Derivative liabilities: Interest rate contracts $ — $ 20,822 $ — 20,822 Visa derivative — — 1,990 1,990 Total derivative liabilities $ — $ 20,822 $ 1,990 $ 22,812 December 31, 2017 (in thousands) Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Assets and Liabilities at Fair Value Assets Trading securities: Mortgage-backed securities issued by U.S. Government agencies $ — $ 3,002 $ — $ 3,002 Collateralized mortgage obligations issued by U.S. Government sponsored enterprises — 296 — 296 Other investments 522 — — 522 Total trading securities $ 522 $ 3,298 $ — $ 3,820 Mortgage loans held for sale — 48,024 — 48,024 Investment securities available for sale: U.S. Treasury securities $ 82,674 $ — $ — $ 82,674 U.S. Government agency securities — 10,862 — 10,862 Mortgage-backed securities issued by U.S. Government agencies — 120,440 — 120,440 Mortgage-backed securities issued by U.S. Government sponsored enterprises — 2,640,523 — 2,640,523 Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises — 1,111,999 — 1,111,999 State and municipal securities — 180 — 180 Corporate debt and other securities 3,162 15,294 1,935 20,391 Total investment securities available for sale $ 85,836 $ 3,899,298 $ 1,935 $ 3,987,069 Private equity investments — — 15,771 15,771 Mutual funds held in rabbi trusts 14,140 — — 14,140 GGL/SBA loan servicing asset — — 4,101 4,101 Derivative assets: Interest rate contracts $ — $ 10,786 $ — $ 10,786 Mortgage derivatives (1) — 936 — 936 Total derivative assets $ — $ 11,722 $ — $ 11,722 Liabilities Trading account liabilities — 1,000 — 1,000 Earnout liability (2) — — 11,348 11,348 Derivative liabilities: Interest rate contracts $ — $ 12,638 $ — $ 12,638 Mortgage derivatives (1) — 129 — 129 Visa derivative — — 4,330 4,330 Total derivative liabilities $ — $ 12,767 $ 4,330 $ 17,097 (1) Mortgage derivatives consist of customer interest rate lock commitments that relate to the potential origination of mortgage loans, which would be classified as held for sale and forward loan sales commitments with third-party investors. (2) Earnout liability consists of contingent consideration obligation related to the Global One acquisition. Fair Value Option The following table summarizes the difference between the fair value and the unpaid principal balance of mortgage loans held for sale measured at fair value and the changes in fair value of these loans. Mortgage loans held for sale are initially measured at fair value with subsequent changes in fair value recognized in earnings. Changes in fair value are recorded as a component of mortgage banking income in the consolidated statements of income. An immaterial portion of these changes in fair value was attributable to changes in instrument-specific credit risk. Changes in Fair Value Included in Net Income For the Three Months Ended September 30, For the Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Mortgage loans held for sale $ (569 ) $ (104 ) $ (414 ) $ 850 Mortgage Loans Held for Sale (in thousands) As of September 30, 2018 As of December 31, 2017 Fair value $ 37,276 $ 48,024 Unpaid principal balance 36,505 46,839 Fair value less aggregate unpaid principal balance $ 771 $ 1,185 Fair Value Measurements Using Significant Unobservable Inputs (Level 3) During the three and nine months ended September 30, 2018 and 2017 , Synovus did not have any transfers in or out of Level 3 in the fair value hierarchy. For the three and nine months ended September 30, 2018 , total net losses included in earnings attributable to the change in unrealized losses relating to assets/liabilities still held at September 30, 2018 was $11.8 million and $17.9 million , respectively. For the three and nine months ended September 30, 2017 , total net losses included in earnings attributable to the change in unrealized losses relating to assets/liabilities still held at September 30, 2017 was $2.1 million and $7.7 million , respectively. Three Months Ended September 30, 2018 (in thousands) Investment Securities Available for Sale Private Equity Investments GGL / SBA Loans Servicing Asset Earnout Visa Derivative Beginning balance, July 1, 2018 $ 1,857 $ 12,678 $ 4,186 $ (11,348 ) $ (5,943 ) Total (losses) gains realized/unrealized: Included in earnings — 434 (561 ) (11,652 ) — Unrealized gains (losses) included in OCI 108 — — — — Additions — — 136 — — Settlements — — — — 3,953 Ending balance, September 30, 2018 $ 1,965 $ 13,112 $ 3,761 $ (23,000 ) $ (1,990 ) Total net losses for the period included in earnings attributable to the change in unrealized losses relating to assets/liabilities still held at September 30, 2018 $ — $ 434 $ (561 ) $ (11,652 ) $ — Three Months Ended September 30, 2017 (in thousands) Investment Securities Available for Sale Private Equity Investments GGL / SBA Earnout Visa Derivative Beginning balance, July 1, 2017 $ 1,927 $ 15,698 $ 4,297 $ (13,941 ) $ (5,053 ) Total (losses) gains realized/unrealized: Included in earnings — (27 ) (27 ) (2,059 ) — Unrealized gains (losses) included in OCI (9 ) — — — — Settlements — — — — 360 Ending balance, September 30, 2017 $ 1,918 $ 15,671 $ 4,270 $ (16,000 ) $ (4,693 ) Total net losses for the period included in earnings attributable to the change in unrealized losses relating to assets/liabilities still held at September 30, 2017 $ — $ (27 ) $ (27 ) $ (2,059 ) $ — Nine Months Ended September 30, 2018 (in thousands) Investment Securities Available for Sale Private Equity Investments GGL / SBA Earnout Visa Derivative Beginning balance, January 1, 2018 $ 1,935 $ 15,771 $ 4,101 $ (11,348 ) $ (4,330 ) Total (losses) gains realized/unrealized: Included in earnings — (2,659 ) (1,295 ) (11,652 ) (2,328 ) Unrealized gains (losses) included in OCI 30 — — — — Additions — — 955 — — Settlements — — — — 4,668 Ending balance, September 30, 2018 $ 1,965 $ 13,112 $ 3,761 $ (23,000 ) $ (1,990 ) Total net losses for the period included in earnings attributable to the change in unrealized losses relating to assets/liabilities still held at September 30, 2018 $ — $ (2,659 ) $ (1,295 ) $ (11,652 ) $ (2,328 ) Nine Months Ended September 30, 2017 (in thousands) Investment Securities Available for Sale Private Equity Investments GGL / SBA Loans Servicing Asset Earnout Liability Visa Derivative Beginning balance, January 1, 2017 $ 1,796 $ 25,493 $ — $ (14,000 ) $ (5,768 ) Total (losses) gains realized/unrealized: Included in earnings — (3,193 ) (721 ) (3,766 ) — Unrealized gains (losses) included in OCI 122 — — — — Additions — — 539 — — Sales and settlements — (6,629 ) — — 1,075 Transfer from amortization method to fair value — — 4,452 — — Measurement period adjustments related to Global One — — — 1,766 — Ending balance, September 30, 2017 $ 1,918 $ 15,671 $ 4,270 $ (16,000 ) $ (4,693 ) Total net losses for the period included in earnings attributable to the change in unrealized losses relating to assets/liabilities still held at September 30, 2017 $ — $ (3,193 ) $ (721 ) $ (3,766 ) $ — Quantitative Information about Level 3 Fair Value Measurements September 30, 2018 December 31, 2017 Assets and liabilities measured at fair value on a recurring basis Valuation Technique Significant Unobservable Input Level 3 Fair Value Range or Weighted Average Level 3 Fair Value Range or Weighted Average Investment Securities Available for Sale - Other Investments: Trust preferred securities Discounted cash flow analysis Credit spread embedded in discount rate $1,965 389 bps $1,935 398 bps Private equity investments Individual analysis of each investee company Multiple factors, including but not limited to, current operations, financial condition, cash flows, evaluation of business management and financial plans, and recently executed financing transactions related to the investee companies 13,112 N/A 15,771 N/A GGL/SBA loans servicing asset Discounted cash flow analysis Discount rate Prepayment speeds 3,761 13.40% 8.64% 4,101 13.16% 7.50% Earnout liability Option pricing methods and Monte Carlo simulation Earning projections of Global One 23,000 N/A 11,348 N/A Visa derivative liability Discounted cash flow analysis Estimated timing of resolution of covered litigation, future cumulative deposits to the litigation escrow for settlement of the covered litigation, and estimated future monthly fees payable to the derivative counterparty 1,990 1-2 years 4,330 1-4 years Assets Measured at Fair Value on a Non-recurring Basis Certain assets are recorded at fair value on a non-recurring basis. Non-recurring fair value adjustments typically are a result of the application of lower of cost or fair value accounting or a write-down occurring during the period. For example, if the fair value of an asset in these categories falls below its cost basis, it is considered to be at fair value at the end of the period of the adjustment. The following table presents assets measured at fair value on a non-recurring basis as of the dates indicated for which there was a fair value adjustment during the nine months ended September 30, 2018 and year ended December 31, 2017 . September 30, 2018 December 31, 2017 (in thousands) Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Impaired loans (1) $ — $ — $ 17,270 $ 17,270 $ — $ — $ 3,603 $ 3,603 Other loans held for sale — — — — — — 10,197 10,197 Other real estate — — 507 507 — — 3,363 3,363 Other assets held for sale — — 302 302 — — 5,334 5,334 (1) Collateral-dependent impaired loans that were written down to fair value during the period. Other real estate (ORE) properties are included in other assets on the consolidated balance sheets. The carrying value of ORE at September 30, 2018 and December 31, 2017 was $8.5 million and $3.8 million , respectively. The following table presents fair value adjustments recognized in earnings for the three and nine months ended September 30, 2018 and 2017 for assets measured at fair value on a non-recurring basis still held at period-end. Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Impaired loans (1) $ 1,223 $ 83 $ 4,594 $ 1,075 Other loans held for sale — 25,051 — 25,051 Other real estate 61 5,165 61 5,165 Other assets held for sale — 1,683 499 1,683 (1) Collateral-dependent impaired loans that were written down to fair value during the period. Quantitative Information about Level 3 Fair Value Measurements September 30, 2018 December 31, 2017 Assets measured at fair value on a non-recurring basis Valuation Technique Significant Unobservable Input Range (Weighted Average) (1) Range (Weighted Average) (1) Collateral dependent impaired loans Third-party appraised value of collateral less estimated selling costs Discount to appraised value Estimated selling costs 0% - 68% (25%) 0% - 10% (7%) 0%-50% (15%) 0%-10% (7%) Other loans held for sale Third-party appraised value of collateral less estimated selling costs Discount to appraised value Estimated selling costs N/A N/A 5% - 99% (54%) 0% - 10% (2%) Other real estate Third-party appraised value of real estate less estimated selling costs Discount to appraised value Estimated selling costs 0% - 7% (4%) 0% - 10% (7%) 0%-85% (35%) 0%-10% (7%) Other assets held for sale Third-party appraised value less estimated selling costs or BOV Discount to appraised value Estimated selling costs 0%-42% (42%) 0%-10% (7%) 21%-52% (25%) 0%-10% (7%) (1) The range represents management's estimate of the high and low of the value that would be assigned to a particular input. For assets measured at fair value on a non-recurring basis, the weighted average is the measure of central tendencies; it is not the value that management is using for the asset or liability. Fair Value of Financial Instruments The following tables present the carrying and fair values of financial instruments, as well as the level within the fair value value hierarchy, at September 30, 2018 and December 31, 2017 . The fair values represent management’s estimates based on various methodologies and assumptions. For financial instruments that are not recorded at fair value on the balance sheet, such as loans held for investment, interest-bearing deposits, and long-term debt, the fair value amounts should not be taken as an estimate of the amount that would be realized if all such financial instruments were to be settled immediately. September 30, 2018 (in thousands) Carrying Value Fair Value Level 1 Level 2 Level 3 Financial assets Total cash, cash equivalents, restricted cash, and restricted cash equivalents $ 1,011,933 $ 1,011,933 $ 1,011,933 $ — $ — Trading account assets 8,849 8,849 998 7,851 — Mortgage loans held for sale 37,276 37,276 — 37,276 — Other loans held for sale 12 12 — — 12 Investment securities available for sale 3,883,574 3,883,574 120,639 3,760,970 1,965 Private equity investments 13,112 13,112 — — 13,112 Mutual funds 3,118 3,118 3,118 — — Mutual funds held in rabbi trusts 14,100 14,100 14,100 — — Loans, net 25,325,666 25,138,896 — — 25,138,896 GGL/SBA loans servicing asset 3,761 3,761 — — 3,761 Derivative assets 10,014 10,014 — 10,014 — Financial liabilities Trading account liabilities 3,540 3,540 — 3,540 — Non-interest bearing deposits $ 7,628,736 $ 7,628,736 $ — $ 7,628,736 $ — Non-time interest-bearing deposits 13,847,104 13,847,104 — 13,847,104 — Time deposits 4,957,818 4,937,216 — 4,937,216 — Total deposits $ 26,433,658 $ 26,413,056 $ — $ 26,413,056 $ — Federal funds purchased and securities sold under repurchase agreements 191,145 191,145 191,145 — — Other short-term borrowings 475,000 475,000 — 475,000 — Long-term debt 1,656,909 1,654,002 — 1,654,002 — Earnout liabilities 23,000 23,000 — — 23,000 Derivative liabilities $ 22,812 $ 22,812 $ — $ 20,822 $ 1,990 December 31, 2017 (in thousands) Carrying Value Fair Value Level 1 Level 2 Level 3 Financial assets Total cash, cash equivalents, restricted cash, and restricted cash equivalents $ 932,933 $ 932,933 $ 932,933 $ — $ — Trading account assets 3,820 3,820 522 3,298 — Mortgage loans held for sale 48,024 48,024 — 48,024 — Other loans for sale 11,356 11,356 11,356 Investment securities available for sale 3,987,069 3,987,069 85,836 3,899,298 1,935 Private equity investments 15,771 15,771 — — 15,771 Mutual funds held in rabbi trusts 14,140 14,140 14,140 — — Loans, net 24,538,196 24,507,141 — — 24,507,141 GGL/SBA loans servicing asset 4,101 4,101 — — 4,101 Derivative assets 11,722 11,722 — 11,722 — Financial liabilities Trading account liabilities 1,000 1,000 — 1,000 — Non-interest-bearing deposits $ 7,686,339 $ 7,686,339 $ — $ 7,686,339 $ — Non-time interest-bearing deposits 13,941,814 13,941,814 — 13,941,814 — Time deposits 4,519,747 4,523,661 — 4,523,661 — Total deposits $ 26,147,900 $ 26,151,814 $ — $ 26,151,814 $ — Federal funds purchased and securities sold under repurchase agreements 161,190 161,190 161,190 — — Other short-term borrowings 100,000 100,000 — 100,000 — Long-term debt 1,606,138 1,621,814 — 1,621,814 — Earnout liabilities 11,348 11,348 — — 11,348 Derivative liabilities $ 17,097 $ 17,097 $ — $ 12,767 $ 4,330

Derivative Instruments

Derivative Instruments	9 Months Ended
	Sep. 30, 2018
Summary of Derivative Instruments [Abstract]
Derivative Instruments	Note 7 - Derivative Instruments As part of its overall interest rate risk management activities, Synovus utilizes derivative instruments to manage its exposure to various types of interest rate risk. These derivative instruments generally consist of interest rate swaps, interest rate lock commitments made to prospective mortgage loan customers, and commitments to sell fixed-rate mortgage loans. Interest rate lock commitments represent derivative instruments since it is intended that such loans will be sold. Synovus may also utilize interest rate swaps to manage interest rate risks primarily arising from its core banking activities. As of September 30, 2018 and December 31, 2017 , Synovus had no outstanding interest rate swap contracts utilized to manage interest rate risk related to core banking activities. Synovus is party to master netting arrangements with its dealer counterparties; however, Synovus does not offset assets and liabilities under these arrangements for financial statement presentation purposes. See "Part II - Item 8. Financial Statements and Supplementary Data - Note 16 - Derivative Instruments" of Synovus' 2017 Form 10-K for additional information on Synovus' derivative instruments. Counterparty Credit Risk and Collateral Entering into derivative contracts potentially exposes Synovus to the risk of counterparties’ failure to fulfill their legal obligations, including, but not limited to, potential amounts due or payable under each derivative contract. Notional principal amounts are often used to express the volume of these transactions, but the amounts potentially subject to credit risk are much smaller. Synovus assesses the credit risk of its dealer counterparties by regularly monitoring publicly available credit rating information, evaluating other market indicators, and periodically reviewing detailed financials. Dealer collateral requirements are determined via risk-based policies and procedures and in accordance with existing agreements. Synovus seeks to minimize dealer credit risk by dealing with highly rated counterparties and by obtaining collateral for exposures above certain predetermined limits. Management closely monitors credit conditions within the customer swap portfolio, which management deems to be of higher risk than dealer counterparties. Collateral is secured at origination and credit related fair value adjustments are recorded against the asset value of the derivative as deemed necessary based upon an analysis, which includes consideration of the current asset value of the swap, customer credit rating, collateral value, and customer standing with regards to its swap contractual obligations and other related matters. Such asset values fluctuate based upon changes in interest rates regardless of changes in notional amounts and changes in customer specific risk. Collateral Requirements Pursuant to the Dodd-Frank Act, certain derivative transactions have collateral requirements, both at the inception of the trade and as the value of each derivative position changes. As of September 30, 2018 , collateral totaling $31.1 million was pledged to the derivative counterparties to comply with collateral requirements. For derivatives cleared through central clearing houses, the variation margin payments made are legally characterized as settlements of the derivatives. As a result, these variation margin payments are netted against the fair value of the respective derivative contracts in the balance sheet and related disclosures. At September 30, 2018 and December 31, 2017 , Synovus had a variation margin of $11.6 million and $1.5 million , respectively, reducing the derivative asset. The following table reflects the notional amount and fair value of derivative instruments included on the consolidated balance sheets. September 30, 2018 December 31, 2017 Fair Value Fair Value (in thousands) Notional Amount Derivative Assets (1) Derivative Liabilities (2) Notional Amount Derivative Assets (1) Derivative Liabilities (2) Derivatives not designated Interest rate contracts (3) $ 1,667,397 $ 8,892 $ 20,822 $ 1,466,059 10,786 $ 12,638 Mortgage derivatives - interest rate lock commitments 59,289 875 — 49,304 936 — Mortgage derivatives - forward commitments to sell fixed-rate mortgage loans 85,500 247 — 72,500 — 129 Visa derivative — — 1,990 — — 4,330 Total derivatives not designated as hedging instruments $ 10,014 $ 22,812 $ 11,722 $ 17,097 (1) Derivative assets are recorded in other assets on the consolidated balance sheets. (2) Derivative liabilities are recorded in other liabilities on the consolidated balance sheets. (3) Includes interest rate contracts for customer swaps and offsetting positions, net of variation margin payments. The pre-tax effect of changes in fair value from derivative instruments not designated as hedging instruments on the consolidated statements of income for the three and nine months ended September 30, 2018 and 2017 is presented below. Gain (Loss) Recognized in Consolidated Statements of Income Three Months Ended September 30, Nine Months Ended September 30, (in thousands) Location in Consolidated Statements of Income 2018 2017 2018 2017 Derivatives not designated as hedging instruments: Interest rate contracts (1) Other non-interest income $ 1 $ (4 ) $ (8 ) $ (5 ) Mortgage derivatives - interest rate lock commitments Mortgage banking income (427 ) (180 ) (61 ) (595 ) Mortgage derivatives - forward commitments to sell fixed-rate mortgage loans Mortgage banking income 495 (271 ) 376 (1,929 ) Visa derivative Other non-interest expense — — (2,328 ) — Total $ 69 $ (455 ) $ (2,021 ) $ (2,529 ) (1) Gain (loss) represents net fair value adjustments (including credit-related adjustments) for customer swaps and offsetting positions.

Shareholders' Equity

Shareholders' Equity	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Shareholders' Equity	Note 8 - Shareholders' Equity Issuance of Series D Preferred Stock On June 21, 2018, Synovus completed a $200 million public offering of Fixed-to-Floating Rate Non-Cumulative Perpetual Preferred Stock, Series D, $25.00 per share liquidation preference. The offering generated net proceeds of $195.1 million . Dividends on the shares are non-cumulative and, if declared, will accrue and be payable, in arrears, quarterly at a rate per annum equal to 6.300% for each dividend period from the original issue date to, but excluding, June 21, 2023. From and including June 21, 2023, the dividend rate will change to a floating rate equal to the three-month LIBOR plus a spread of 3.352% per annum. The Series D Preferred Stock is perpetual and has no maturity date. The Series D Preferred Stock is redeemable at Synovus' option in whole or in part, from time to time, on any dividend payment date on or after June 21, 2023, or in whole, but not in part, at any time within 90 days following a regulatory capital treatment event at a redemption price equal to $25.00 per share, plus any declared and unpaid dividends, without accumulation of any undeclared dividends. The Series D Preferred Stock has no preemptive or conversion rights. Except in limited circumstances, the Series D Preferred Stock does not have any voting rights. Redemption of Series C Preferred Stock On August 1, 2018, Synovus redeemed all 5,200,000 outstanding shares of Series C Preferred Stock for a cash price of $25.00 per share, without interest, for an aggregate redemption price of $130.0 million and paid a dividend of $2.6 million on the Series C Preferred Stock. The redemption of the Series C Preferred Stock was funded primarily with proceeds from Synovus' public offering of $200 million of Series D Preferred Stock completed in June 2018. Concurrent with the redemption, Synovus recognized a one-time, non-cash redemption charge of $4.0 million . Repurchases of Common Stock On January 23, 2018 , Synovus announced a share repurchase program of up to $150 million to be completed during 2018. As of September 30, 2018 , Synovus had repurchased under this program a total of $134.8 million , or 2.6 million shares of its common stock, at an average price of $51.85 per share. As of September 30, 2018 , the remaining authorization under this program was $15.2 million . During October 2018, the program was concluded with the remaining $15.2 million , or 345 thousand shares, repurchased. In total, 2.9 million shares were repurchased during 2018 at an average price of $50.96 per share.

Net Income Per Common Share

Net Income Per Common Share	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Net Income Per Common Share	Note 9 - Net Income Per Common Share The following table displays a reconciliation of the information used in calculating basic and diluted earnings per common share for the three and nine months ended September 30, 2018 and 2017 . Three Months Ended September 30, Nine Months Ended September 30, (in thousands, except per share data) 2018 2017 2018 2017 Basic Net Income Per Common Share: Net income available to common shareholders $ 99,330 $ 95,448 $ 308,559 $ 238,190 Weighted average common shares outstanding 117,241 120,900 118,096 121,796 Net income per common share, basic $ 0.85 $ 0.79 $ 2.61 $ 1.96 Diluted Net Income Per Common Share: Net income available to common shareholders $ 99,330 $ 95,448 $ 308,559 $ 238,190 Weighted average common shares outstanding 117,241 120,900 118,096 121,796 Potentially dilutive shares from outstanding equity-based awards and earnout payments 854 914 751 832 Weighted average diluted common shares 118,095 121,814 118,847 122,628 Net income per common share, diluted $ 0.84 $ 0.78 $ 2.60 $ 1.94 Basic net income per common share is computed by dividing net income available to common shareholders by the average common shares outstanding for the period. Diluted net income per common share reflects the dilution that could occur if securities or other contracts to issue common stock were exercised or converted. The dilutive effect of outstanding stock options and restricted share units is reflected in diluted net income per common share, unless the impact is anti-dilutive, by application of the treasury stock method. As of September 30, 2018 and 2017 , there were 2.2 million potentially dilutive shares related to the Warrant to purchase shares of common stock that were outstanding during 2018 and 2017 but were not included in the computation of diluted net income per common share because the effect would have been anti-dilutive.

Share-based Compensation

Share-based Compensation	9 Months Ended
	Sep. 30, 2018
Share-based Compensation [Abstract]
Share-based Compensation	Note 10 - Share-based Compensation General Description of Share-based Plans Synovus has a long-term incentive plan under which the Compensation Committee of the Board of Directors has the authority to grant share-based awards to Synovus employees. The 2013 Omnibus Plan authorizes 8.6 million common share equivalents available for grant, where grants of options count as one share equivalent and grants of full value awards (e.g., restricted share units, market restricted share units, and performance share units) count as two share equivalents. Any restricted share units that are forfeited and options that expire unexercised will again become available for issuance under the Plan. At September 30, 2018 , Synovus had a total of 4.9 million shares of its authorized but unissued common stock reserved for future grants under the 2013 Omnibus Plan. The Plan permits grants of share-based compensation including stock options, restricted share units, market restricted share units, and performance share units. The grants generally include vesting periods ranging from three to five years and contractual terms of ten years. Vesting for grants made in 2018 accelerates upon retirement for plan participants who have reached age 65 and who also have no less than 10 years of service at the date of their election to retire. Market restricted share units and performance share units are granted at a defined target level and are compared annually to required market and performance metrics to determine actual units vested and compensation expense. Synovus has historically issued new shares to satisfy share option exercises and share unit conversions. Dividend equivalents are paid on outstanding restricted share units, market restricted share units, and performance share units in the form of additional restricted share units that vest over the same vesting period or the vesting period left on the original restricted share unit grant. Share-based Compensation Expense Total share-based compensation expense was $4.2 million and $12.5 million for the three and nine months ended September 30, 2018 , respectively, and $3.7 million and $10.6 million for the three and nine months ended September 30, 2017 , respectively. Stock Options No stock option grants were made during the nine months ended September 30, 2018 . At September 30, 2018 , there were 643 thousand outstanding stock options to purchase shares of common stock with a weighted average exercise price of $16.94 per share. Restricted Share Units, Performance Share Units, and Market Restricted Share Units During the nine months ended September 30, 2018 , Synovus awarded 236 thousand restricted share units that have a service-based vesting period of three years and awarded 87 thousand performance share units that vest upon service and performance conditions. Synovus also granted 58 thousand market restricted share units during the nine months ended September 30, 2018 . The weighted average grant-date fair value of the awarded restricted share units, performance share units and market restricted share units was $47.69 per share. Market restricted share units and performance share units are granted at target and are compared annually to required market and performance metrics. The performance share units vest upon meeting certain service and performance conditions. Return on average assets (ROAA) and return on average tangible common equity (ROATCE) performance is evaluated each year over a three-year performance period, with share distribution determined at the end of the three years. The number of performance share units that will ultimately vest ranges from 0% to 150% of target based on Synovus' three-year weighted average ROAA (as defined) and ROATCE (as defined). The market restricted share units have a three -year service-based vesting component as well as a total shareholder return multiplier. The number of market restricted share units that will ultimately vest ranges from 75% to 125% of target based on Synovus' total shareholder return. At September 30, 2018 , including dividend equivalents granted, there were 909 thousand restricted share units, performance share units and market restricted share units outstanding with a weighted average grant-date fair value of $40.86 per share.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Note 11 - Income Taxes Synovus' provision for income taxes for the three and nine months ended September 30, 2018 and 2017 is based on the estimated annual effective tax rate, plus discrete items. The following table presents the provision for income taxes and the effective tax rates for the periods indicated. Three Months Ended September 30, Nine Months Ended September 30, (dollars in thousands) 2018 2017 2018 2017 Income before income tax expense $ 128,008 $ 152,675 $ 403,502 $ 376,171 Income tax expense 18,949 54,668 80,095 130,303 Effective tax rate 14.8 % 35.8 % 19.8 % 34.6 % The difference between Synovus' effective tax rate for the three and nine months ended September 30, 2018 and the U.S. statutory tax rate of 21%, primarily relates to third quarter 2018 discrete tax benefits of $12.7 million , which included a $3.9 million tax benefit for the refinement of provisional amounts previously reported under SEC Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act (SAB 118), a $5.5 million return to provision benefit associated with the preparation of the 2017 tax return and a $3.3 million benefit associated with insignificant adjustments to tax returns from several prior years. In addition, the effective income tax rate for the nine months ended September 30, 2018 included a net discrete income tax benefit of $2.8 million resulting from tax benefits associated with the exercise and vesting of employee equity awards. Other items impacting the difference between Synovus' effective tax rates for the three and nine months ended September 30, 2018 and 2017 and the U.S. statutory tax rates of 21% and 35%, respectively, primarily relate to, but are not limited to, the level of pre-tax income, bank-owned life insurance, state income taxes (net of federal income tax benefit), tax-exempt interest and nondeductible expenses. In addition, the effective tax rate is affected by items that may occur in any given period but are not consistent from period-to-period, such as tax benefits related to share-based compensation, jurisdiction statutory tax rate changes, valuation allowance changes and changes to unrecognized tax benefits. Accordingly, the comparability of the effective tax rate between periods may be impacted. Impact of Tax Reform On December 22, 2017, Federal Tax Reform was enacted into law. The new legislation included a decrease in the U.S. statutory tax rate from 35% to 21% effective January 1, 2018. Under ASC 740, the effects of the changes in tax rates and laws are recognized in the period in which the new legislation is enacted. Therefore, Synovus was required to remeasure its deferred tax assets and liabilities and record the adjustment to income tax expense effective December 22, 2017. In December 2017, the SEC issued SAB 118, which allowed companies to record provisional amounts during a measurement period not to extend beyond one year of the enactment date. Since Federal Tax Reform was enacted late in 2017, Synovus expected that certain deferred tax assets and liabilities would continue to be evaluated in the context of Federal Tax Reform through the date of the filing of the 2017 federal income tax return, and that changes might result from evolving internal interpretations, elections, and assumptions, as well as new guidance that may be issued by the Internal Revenue Service. Accordingly, the federal income tax expense of $47.2 million recorded in 2017 relating to the effects from Federal Tax Reform was considered provisional. During the third quarter of 2018, Synovus completed its 2017 federal income tax return and recorded a $3.9 million tax benefit for the refinement of provisional amounts previously reported under SAB 118; thus, the accounting under SAB 118 for Federal Tax Reform is now complete.

Non-interest Income

Non-interest Income	9 Months Ended
	Sep. 30, 2018
Revenue from Contract with Customer [Abstract]
Non-interest Income	Note 12 - Non-interest Income The following table reflects revenue disaggregated by revenue type and line of business for the three and nine months ended September 30, 2018 and 2017 . Non-interest Income by Line of Business For the Three Months Ended September 30, 2018 (in thousands) Community Banking Corporate Banking Retail Banking Financial Management Services Other Total Service charges on deposit accounts $ 5,660 $ 475 $ 13,792 $ — $ 655 $ 20,582 Fiduciary and asset management fees — — — 13,462 — 13,462 Card fees 208 — 10,400 — — 10,608 Brokerage revenue — — — 9,329 — 9,329 Insurance revenue — — — 1,148 — 1,148 Other fees — — 454 — 266 720 $ 5,868 $ 475 $ 24,646 $ 23,939 $ 921 $ 55,849 Other revenues (1) 1,142 1,836 1,645 5,994 5,202 15,819 Total non-interest income $ 7,010 $ 2,311 $ 26,291 $ 29,933 $ 6,123 $ 71,668 For the Three Months Ended September 30, 2017 (in thousands) Community Banking Corporate Banking Retail Banking Financial Management Services Other Total Service charges on deposit accounts $ 5,613 $ 432 $ 14,024 $ — $ 609 $ 20,678 Fiduciary and asset management fees — — — 12,615 — 12,615 Card fees 210 — 9,519 — — 9,729 Brokerage revenue — — — 7,511 — 7,511 Insurance revenue — — — 1,059 — 1,059 Other fees — — 463 — 265 728 $ 5,823 $ 432 $ 24,006 $ 21,185 $ 874 $ 52,320 Other revenues (1) 2,642 1,460 1,574 6,558 70,881 83,115 Total non-interest income $ 8,465 $ 1,892 $ 25,580 $ 27,743 $ 71,755 $ 135,435 ( 1) Other revenues primarily relate to revenues not derived from contracts with customers. Non-interest Income by Line of Business For the Nine Months Ended September 30, 2018 (in thousands) Community Banking Corporate Banking Retail Banking Financial Management Services Other Total Service charges on deposit accounts $ 17,064 $ 1,460 $ 40,310 $ — $ 1,687 $ 60,521 Fiduciary and asset management fees — — — 40,881 — 40,881 Card fees 628 — 31,012 — — 31,640 Brokerage revenue — — — 26,924 — 26,924 Insurance revenue — — — 4,240 — 4,240 Other fees — — 1,487 — 821 2,308 $ 17,692 $ 1,460 $ 72,809 $ 72,045 $ 2,508 $ 166,514 Other revenues (1) 6,983 5,417 4,887 17,402 10,898 45,587 Total non-interest income $ 24,675 $ 6,877 $ 77,696 $ 89,447 $ 13,406 $ 212,101 For the Nine Months Ended September 30, 2017 (in thousands) Community Banking Corporate Banking Retail Banking Financial Management Services Other Total Service charges on deposit accounts $ 17,028 $ 1,319 $ 40,994 $ — $ 1,707 $ 61,048 Fiduciary and asset management fees — — — 37,290 — 37,290 Card fees 647 — 28,967 — — 29,614 Brokerage revenue — — — 21,947 — 21,947 Insurance revenue — — — 3,424 — 3,424 Other fees — — 1,525 — 795 2,320 $ 17,675 $ 1,319 $ 71,486 $ 62,661 $ 2,502 $ 155,643 Other revenues (1) 7,283 5,836 4,756 19,971 82,485 120,331 Total non-interest income $ 24,958 $ 7,155 $ 76,242 $ 82,632 $ 84,987 $ 275,974 ( 1) Other revenues primarily relate to revenues not derived from contracts with customers. Following is a discussion of key revenues within the scope of Topic 606: Service Charges on Deposit Accounts : Revenue from service charges on deposit accounts is earned through cash management, wire transfer, and other deposit-related services, as well as overdraft, non-sufficient funds, account management and other deposit-related fees. Revenue is recognized for these services either over time, corresponding with deposit accounts' monthly cycle, or at a point in time for transaction-related services and fees. Payment for service charges on deposit accounts is primarily received immediately or in the following month through a direct charge to customers' accounts. Fiduciary and Asset Management Fees : Fiduciary and asset management fees are primarily comprised of fees earned from the management and administration of trusts and other customer assets. Synovus' performance obligation is generally satisfied over time and the resulting fees are recognized monthly, based upon the month-end market value of the assets under management and the applicable fee rate. Payment is generally received a few days after month-end through a direct charge to customers' accounts. Synovus does not earn performance-based incentives. Card Fees: Card fees consist primarily of interchange fees from consumer credit and debit cards processed by card association networks, as well as merchant discounts, and other card-related services. Interchange rates are generally set by the credit card associations and based on purchase volumes and other factors. Interchange fees and merchant discounts are recognized concurrently with the delivery of service on a daily basis as transactions occur. Payment is typically received immediately or in the following month. Card fees are reported net of certain associated expense items including loyalty program expenses and network expenses. Brokerage Revenue: Brokerage revenue consists primarily of commissions. Additionally, brokerage revenue includes advisory fees earned from the management of customer assets. Advisory fees for brokerage services are recognized and collected monthly and are based upon the month-end market value of the assets under management at a rate predetermined in the contract. Transactional revenues are based on the size and number of transactions executed at the client's direction and are generally recognized on the trade date with payment received on the settlement date. Insurance Revenue: Insurance revenue primarily consists of commissions received on annuity and life product sales. The commissions are recognized as revenue when the customer executes an insurance policy with the insurance carrier. In some cases, Synovus receives payment of trailing commissions each year when the customer pays its annual premium. For the three and nine months ended September 30, 2018 , Synovus recognized an immaterial amount of insurance trailing commissions. Other Fees: Other fees primarily consist of revenues generated from safe deposit box rental fees and lockbox services. Fees are recognized over time, on a monthly basis, as Synovus' performance obligation for services is satisfied. Payment is received upfront for safe deposit box rentals and in the following month for lockbox services.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 13 - Commitments and Contingencies In the normal course of business, Synovus enters into commitments to extend credit such as loan commitments and letters of credit to meet the financing needs of its customers. Synovus uses the same credit policies in making commitments and conditional obligations as it does for on-balance sheet instruments. Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established in the contract. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. The contractual amount of these financial instruments represents Synovus' maximum credit risk should the counterparty draw upon the commitment, and should the counterparty subsequently fail to perform according to the terms of the contract. Since many of the commitments are expected to expire without being drawn upon, total commitment amounts do not necessarily represent future cash requirements. Additionally, certain commitments (primarily consumer) may generally be canceled by providing notice to the borrower. The allowance for credit losses associated with unfunded commitments and letters of credit is a component of the unfunded commitments reserve recorded within other liabilities on the consolidated balance sheets. Additionally, unearned fees relating to letters of credit are recorded within other liabilities on the consolidated balance sheets. These amounts are not material to Synovus' consolidated balance sheets. Unfunded letters of credit and lending commitments at September 30, 2018 and December 31, 2017 are presented below. (in thousands) September 30, 2018 December 31, 2017 Letters of credit* $ 167,969 $ 153,372 Commitments to fund commercial and industrial loans 5,688,192 5,090,827 Commitments to fund commercial real estate, construction, and land development loans 1,763,006 1,567,583 Commitments under home equity lines of credit 1,211,861 1,137,714 Unused credit card lines 766,521 779,254 Other loan commitments 394,428 351,358 Total unfunded lending commitments and letters of credit $ 9,991,977 $ 9,080,108 * Represent the contractual amount net of risk participations of approximately $70 million and $77 million at September 30, 2018 and December 31, 2017 , respectively. Merchant Services In accordance with credit and debit card association rules, Synovus sponsors merchant processing servicers that process credit and debit card transactions on behalf of various merchants. In connection with these services, a liability may arise in the event of a billing dispute between the merchant and a cardholder that is ultimately resolved in the cardholder's favor. If the merchant defaults on its obligation to reimburse the cardholder, the cardholder, through its issuing bank, generally has until six months after the date of the transaction to present a chargeback to the merchant processor, which is primarily liable for any losses on covered transactions. However, if the merchant processor fails to meet its obligation to reimburse the cardholder for disputed transactions, then Synovus, as the sponsor, could be held liable for the disputed amount. Synovus seeks to mitigate this risk through its contractual arrangements with the merchant processing servicers and the merchants and by withholding future settlements, by retaining cash reserve accounts or by obtaining other security. For the three and nine months ended September 30, 2018 , the sponsored entities processed and settled $17.69 billion and $52.04 billion of transactions, respectively. For the three and nine months ended September 30, 2017 , the sponsored entities processed and settled $15.84 billion and $46.26 billion of transactions, respectively. Synovus began covering and may continue to cover chargebacks related to a merchant processing servicer during the third quarter of 2018 where the merchant processing servicer’s cash reserve account was unavailable to support the chargebacks. Synovus expects to recover these amounts from the servicer under the terms of the contract; however, any inability by Synovus to fully recover these amounts would result in losses to Synovus in future periods. Legal Proceedings Synovus and its subsidiaries are subject to various legal proceedings and claims that arise in the ordinary course of its business. Additionally, in the ordinary course of business, Synovus and its subsidiaries are subject to regulatory examinations, information gathering requests, inquiries and investigations. Synovus, like many other financial institutions, has been the target of numerous legal actions and other proceedings asserting claims for damages and related relief for losses. These actions include claims and counterclaims asserted by individual borrowers related to their loans and allegations of violations of state and federal laws and regulations relating to banking practices, including putative class action matters. In addition to actual damages, if Synovus does not prevail in asserted legal actions, credit-related litigation could result in additional write-downs or charge-offs of loans, which could adversely affect Synovus' results of operations during the period in which the write-down or charge-off were to occur. Synovus carefully examines and considers each legal matter, and, in those situations where Synovus determines that a particular legal matter presents loss contingencies that are both probable and reasonably estimable, Synovus establishes an appropriate reserve. An event is considered to be probable if the future event is likely to occur. While the final outcome of any legal proceeding is inherently uncertain, based on the information currently available, advice of counsel and available insurance coverage, management believes that the amounts accrued with respect to legal matters as of September 30, 2018 are adequate. The actual costs of resolving legal claims may be higher or lower than the amounts accrued. In addition, where Synovus determines that there is a reasonable possibility of a loss in respect of legal matters, Synovus considers whether it is able to estimate the total reasonably possible loss or range of loss. An event is “reasonably possible” if “the chance of the future event or events occurring is more than remote but less than likely.” An event is “remote” if “the chance of the future event or events occurring is more than slight but less than reasonably possible." In many situations, Synovus may be unable to estimate reasonably possible losses due to the preliminary nature of the legal matters, as well as a variety of other factors and uncertainties. For those legal matters where Synovus is able to estimate a range of reasonably possible losses, management currently estimates the aggregate range from our outstanding litigation is from zero to $5 million in excess of the amounts accrued, if any, related to those matters. This estimated aggregate range is based upon information currently available to Synovus, and the actual losses could prove to be lower or higher. As there are further developments in these legal matters, Synovus will reassess these matters, and the estimated range of reasonably possible losses may change as a result of this assessment. Based on Synovus' current knowledge and advice of counsel, management presently does not believe that the liabilities arising from these legal matters will have a material adverse effect on Synovus' consolidated financial condition, results of operations or cash flows. However, it is possible that the ultimate resolution of these legal matters could have a material adverse effect on Synovus' results of operations for any particular period. Synovus intends to vigorously pursue all available defenses to these legal matters, but will also consider other alternatives, including settlement, in situations where there is an opportunity to resolve such legal matters on terms that Synovus considers to be favorable, including in light of the continued expense and distraction of defending such legal matters. Synovus maintains insurance coverage, which may be available to cover legal fees, or potential losses that might be incurred in connection with such legal matters. The above-noted estimated range of reasonably possible losses does not take into consideration insurance coverage which may or may not be available for the respective legal matters.

Pending Acquisition and Pending

Pending Acquisition and Pending Branch Sales	9 Months Ended
	Sep. 30, 2018
Subsequent Events [Abstract]
Pending Acquisition and Pending Branch Sales	Note 14 - Pending Acquisition and Pending Branch Sales Pending Acquisition of FCB Financial Holdings, Inc. On July 23, 2018, Synovus entered into the Merger Agreement by and among Synovus, FCB and Azalea Merger Sub Corp. pursuant to which Synovus will acquire FCB in a reverse triangular merger. FCB is headquartered in Weston, Florida with reported assets of $12.19 billion as of June 30, 2018. At the effective time of the Merger, each outstanding share of FCB Class A common stock, par value $0.001 per share, will be converted into the right to receive, without interest, 1.055 shares of Synovus common stock, par value $1.00 per share. The Merger Agreement has been unanimously approved by both companies’ Board of Directors. The transaction is subject to customary closing conditions, including approval of Synovus and FCB shareholders and approval of state and federal regulators, and is expected to close by the first quarter of 2019. FCB operates 50 full service banking centers through its wholly-owned banking subsidiary, Florida Community Bank. Following closing, Florida Community Bank will merge with and into Synovus Bank and operate under the Synovus brand. Pending Branch Sales On August 28, 2018, Synovus Bank entered into a purchase and assumption agreement with Jefferson Financial Federal Credit Union pursuant to which Jefferson Financial Federal Credit Union will acquire certain assets, including selected loans, and assume substantially all of the deposits associated with two branches in Mobile, Alabama, and one branch in Daphne, Alabama. The agreement provides for the transfer of approximately $138 million in loans, approximately $107 million in deposits, and other assets associated with the three branches in exchange for a deposit premium of $14.5 million . The transaction is subject to regulatory approval and satisfaction of customary closing conditions and is expected to be completed in the first quarter of 2019.

Basis of Presentation (Policies

Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Basis of Presentation	The accompanying unaudited interim consolidated financial statements have been prepared in accordance with the instructions to the SEC Form 10-Q and Article 10 of Regulation S-X; therefore, they do not include all information and footnotes necessary for a fair presentation of financial position, results of operations, comprehensive income, and cash flows in conformity with GAAP. All adjustments consisting of normally recurring accruals that, in the opinion of management, are necessary for a fair presentation of the consolidated financial position and results of operations for the periods covered by this Report have been included. The accompanying unaudited interim consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes appearing in Synovus' 2017 Form 10-K .
Reclassifications	In connection with the adoption of ASU 2016-18, Statement of Cash Flows-Restricted Cash , Synovus changed its presentation of cash and cash equivalents, effective January 1, 2018, to include cash and due from banks as well as interest-bearing funds with Federal Reserve Bank, interest earning deposits with banks, and federal funds sold and securities purchased under resale agreements, which are inclusive of any restricted cash and restricted cash equivalents. Prior to 2018, cash and cash equivalents only included cash and due from banks. Prior periods have been revised to maintain comparability. Excluding the aforementioned presentation change and the recently adopted accounting standards listed below, there have been no significant changes to the accounting policies as disclosed in Synovus' 2017 Form 10-K . Prior periods' consolidated financial statements are reclassified whenever necessary to conform to the current periods' presentation.
Use of Estimates in the Preparation of Financial Statements	In preparing the unaudited interim consolidated financial statements in accordance with GAAP, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities as of the date of the respective consolidated balance sheets and the reported amounts of revenues and expenses for the periods presented. Actual results could differ from those estimates. Material estimates that are particularly susceptible to significant change relate to the determination of the allowance for loan losses and the fair value of investment securities.
Accounting Standards Updates	Recently Adopted Accounting Standards ASU 2014-09, Revenue from Contracts with Customers (Topic 606) issued by the FASB in May 2014 , and all subsequent ASUs that modified Topic 606. ASU 2014-09 implements a common revenue standard that establishes principles for reporting information about the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts to provide goods or services to customers. The core principle of the revenue model is that a company will recognize revenue when it transfers control of goods or services to customers at an amount that reflects the consideration to which it expects to be entitled in exchange for those goods or services. The scope of the guidance explicitly excludes net interest income as well as many other revenues from financial assets. Management reviewed its revenue streams and contracts with customers and did not identify material changes to the timing or amount of revenue recognition. Synovus adopted these ASUs on the required effective date of January 1, 2018 utilizing the modified retrospective method of adoption. The adoption resulted in a cumulative effect adjustment of ($685) thousand to the opening balance of retained earnings. Beginning January 1, 2018, in connection with the adoption of this standard, Synovus began including merchant discounts and other card-related fees in card fees. For periods prior to January 1, 2018, these amounts were previously presented in other non-interest income and have been reclassified for comparability. See "Part I - Item 1. Financial Statements and Supplementary Data - Note 12 - Non-interest Income" for the required disclosures in accordance with this ASU. ASU 2018-02, Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. In February 2018, the FASB issued final guidance on reclassification of tax effects stranded in other comprehensive income due to Federal Tax Reform. The guidance provides entities the option to reclassify the tax effects that are stranded in accumulated other comprehensive income, or AOCI, as a result of Federal Tax Reform to retained earnings. The guidance is effective for fiscal years beginning after December 15, 2018; early adoption is permitted. Synovus elected to early adopt ASU 2018-02 as of January 1, 2018 and elected to reclassify the income tax effects of Federal Tax Reform from AOCI to retained earnings. For Synovus, tax effects stranded in AOCI due to Federal Tax Reform totaled $7.6 million at December 31, 2017 and primarily related to unrealized losses on the available-for-sale investment securities portfolio. The reclassification adjustment resulted in an increase to retained earnings as of January 1, 2018 of $7.6 million and a corresponding decrease to AOCI for the same amount. ASU 2016-01, Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilitie s. In January 2016, the FASB issued ASU 2016-01, which included targeted amendments to accounting guidance for recognition, measurement, presentation, and disclosure of financial instruments. ASU 2016-01 requires equity investments (except those accounted for under the equity method of accounting or those that are consolidated) to be measured at fair value with changes in fair value recognized in net income. This ASU requires a cumulative-effect adjustment to retained earnings as of the beginning of the reporting period of adoption to reclassify the cumulative change in fair value of equity securities previously recognized in AOCI. ASU 2016-01 became effective for Synovus on January 1, 2018. The adoption of the guidance resulted in a transfer of investments in mutual funds of $3.2 million , at fair value, from investment securities available for sale to other assets and a $117 thousand cumulative-effect adjustment that decreased retained earnings, with offsetting related adjustments to deferred taxes and AOCI. ASU 2016-01 also emphasizes the existing requirement to use an exit price concept to measure fair value for disclosure purposes in determining the fair value of loans. Determination of the fair value under the exit price method requires judgment because substantially all of the loans within the loan portfolio do not have observable market prices. The adoption of this guidance did not have a significant impact on Synovus' fair value disclosures. ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement . In August 2018, the FASB issued ASU 2018-13, which changes the fair value measurement disclosure requirements of ASC 820. The amendments in this ASU remove, modify, and add certain required disclosures on fair value measurements. The guidance is effective for fiscal years beginning after December 15, 2019; early adoption is permitted. Synovus elected to early adopt ASU 2018-13 for eliminated and modified disclosures upon issuance of this ASU. Synovus will delay adoption of the additional disclosures until their effective date. The adoption of this guidance did not have a significant impact on Synovus' fair value disclosures. ASU 2018-15, Intangibles - Goodwill and Other - Internal Use Software (Subtopic 350-40): Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That is a Service Contract. In August 2018, the FASB issued ASU 2018-15, which amends ASC 350-40. The ASU aligns the requirements for capitalizing implementation costs for a hosting arrangement that is a service contract with those incurred for hosting arrangements that contain a software license as well as those incurred to develop or implement software for internal use. This guidance is effective for fiscal years beginning after December 15, 2019; early adoption is permitted. Synovus elected to early adopt ASU 2018-15, on a prospective basis, upon issuance of this ASU. As of September 30, 2018, no implementation costs have been capitalized under this ASU. Synovus expects to capitalize certain qualifying implementation, set-up, and other upfront costs related to hosting arrangements under a service contract during the fourth quarter of 2018. Recently Issued Accounting Standards Not Yet Adopted ASU 2016-13, Financial Instruments--Credit Losses (CECL). In June 2016, the FASB issued new guidance related to credit losses. The new guidance replaces the existing incurred loss impairment guidance with an expected credit loss methodology. The new guidance will require management’s estimate of credit losses over the full remaining expected life of loans and other financial instruments. For Synovus, the standard will apply to loans, unfunded loan commitments, and debt securities available for sale. The standard is effective for fiscal years beginning after December 15, 2019 and interim periods within those fiscal years with early adoption permitted on January 1, 2019. Synovus will adopt the guidance on January 1, 2020. Upon adoption, Synovus will record a cumulative-effect adjustment to retained earnings as of the beginning of the reporting period of adoption. Synovus has begun its implementation efforts which are led by a cross-functional steering committee. Management expects that the allowance for loan losses will be higher under the new standard; however, management is still in the process of determining the magnitude of the impact on its financial statements and regulatory capital ratios. Additionally, the extent of the expected increase on the allowance for loan losses will depend upon the composition of the loan portfolio upon adoption of the standard, as well as economic conditions and forecasts at that time. ASU 2016-02 , Leases (ASC 842) . In February 2016, the FASB issued ASU 2016-02, its new standard on lease accounting. ASU 2016-02 introduces a lessee model that brings most leases on the balance sheet. Under the new standard, all lessees will recognize a right-of-use asset and a lease liability, including operating leases, with a lease term greater than 12 months. From a lessor perspective, the accounting model is largely unchanged from existing GAAP. Additional amendments include, but are not limited to, the elimination of leveraged leases; modification to the definition of a lease; amendments on sale and leaseback transactions; and disclosure of additional qualitative and quantitative information. In July 2018, the FASB issued ASU 2018-11 , Leases (ASC 842), Targeted Improvements . The ASU 2018-11 amendments include an optional transition method to apply ASU 2016-02 on a prospective basis as of the effective date, with a cumulative- effect adjustment to retained earnings in the period of adoption, instead of applying the guidance using the modified retrospective approach as originally required under ASU 2016-02. ASU 2018-11 also provides lessors with a practical expedient, by class of underlying asset, to not separate lease and non-lease components under certain circumstances, and clarifies which guidance (ASC 842 or ASC 606) to apply to the combined lease and non-lease components. Synovus will elect the optional transition method provided through ASU 2018-11 and will adopt ASU 2016-02 prospectively on January 1, 2019. Synovus will elect the package of practical expedients to not reassess (a) whether existing contracts contain leases, (b) lease classification for existing leases, and (c) initial direct cost for any existing leases. Synovus currently expects to recognize lease liabilities and corresponding right-of-use assets (at their present value) related to substantially all of the $230 million of future minimum lease commitments as disclosed in Note 7 of Synovus' 2017 Form 10-K. Additionally, Synovus expects to recognize a cumulative-effect adjustment upon adoption to increase the beginning balance of retained earnings as of January 1, 2019 for any remaining deferred gains on sale-leaseback transactions that occurred prior to the date of initial application. Synovus had approximately $5.2 million of such deferred gains recorded as of September 30, 2018. Synovus does not expect this ASU to have a material impact on the timing of expense recognition in its consolidated statements of income.
Revenue from Contracts with Customers	Following is a discussion of key revenues within the scope of Topic 606: Service Charges on Deposit Accounts : Revenue from service charges on deposit accounts is earned through cash management, wire transfer, and other deposit-related services, as well as overdraft, non-sufficient funds, account management and other deposit-related fees. Revenue is recognized for these services either over time, corresponding with deposit accounts' monthly cycle, or at a point in time for transaction-related services and fees. Payment for service charges on deposit accounts is primarily received immediately or in the following month through a direct charge to customers' accounts. Fiduciary and Asset Management Fees : Fiduciary and asset management fees are primarily comprised of fees earned from the management and administration of trusts and other customer assets. Synovus' performance obligation is generally satisfied over time and the resulting fees are recognized monthly, based upon the month-end market value of the assets under management and the applicable fee rate. Payment is generally received a few days after month-end through a direct charge to customers' accounts. Synovus does not earn performance-based incentives. Card Fees: Card fees consist primarily of interchange fees from consumer credit and debit cards processed by card association networks, as well as merchant discounts, and other card-related services. Interchange rates are generally set by the credit card associations and based on purchase volumes and other factors. Interchange fees and merchant discounts are recognized concurrently with the delivery of service on a daily basis as transactions occur. Payment is typically received immediately or in the following month. Card fees are reported net of certain associated expense items including loyalty program expenses and network expenses. Brokerage Revenue: Brokerage revenue consists primarily of commissions. Additionally, brokerage revenue includes advisory fees earned from the management of customer assets. Advisory fees for brokerage services are recognized and collected monthly and are based upon the month-end market value of the assets under management at a rate predetermined in the contract. Transactional revenues are based on the size and number of transactions executed at the client's direction and are generally recognized on the trade date with payment received on the settlement date. Insurance Revenue: Insurance revenue primarily consists of commissions received on annuity and life product sales. The commissions are recognized as revenue when the customer executes an insurance policy with the insurance carrier. In some cases, Synovus receives payment of trailing commissions each year when the customer pays its annual premium. For the three and nine months ended September 30, 2018 , Synovus recognized an immaterial amount of insurance trailing commissions. Other Fees: Other fees primarily consist of revenues generated from safe deposit box rental fees and lockbox services. Fees are recognized over time, on a monthly basis, as Synovus' performance obligation for services is satisfied. Payment is received upfront for safe deposit box rentals and in the following month for lockbox services.

Investment Securities Availab_2

Investment Securities Available for Sale (Tables)	9 Months Ended
	Sep. 30, 2018
Investments [Abstract]
Summary of Available-for-Sale Investment Securities	The amortized cost, gross unrealized gains and losses, and estimated fair values of investment securities available for sale at September 30, 2018 and December 31, 2017 are summarized below. September 30, 2018 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. Treasury securities $ 123,265 $ — $ (2,626 ) $ 120,639 U.S. Government agency securities 38,020 102 (258 ) 37,864 Mortgage-backed securities issued by U.S. Government agencies 104,933 75 (4,125 ) 100,883 Mortgage-backed securities issued by U.S. Government sponsored enterprises 2,592,827 70 (103,532 ) 2,489,365 Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises 1,168,378 — (50,675 ) 1,117,703 Corporate debt and other debt securities 17,000 155 (35 ) 17,120 Total investment securities available for sale $ 4,044,423 $ 402 $ (161,251 ) $ 3,883,574 December 31, 2017 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. Treasury securities $ 83,608 $ — $ (934 ) $ 82,674 U.S. Government agency securities 10,771 91 — 10,862 Mortgage-backed securities issued by U.S. Government agencies 121,283 519 (1,362 ) 120,440 Mortgage-backed securities issued by U.S. Government sponsored enterprises 2,666,818 5,059 (31,354 ) 2,640,523 Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises 1,135,259 144 (23,404 ) 1,111,999 State and municipal securities 180 — — 180 Corporate debt and other securities 20,320 294 (223 ) 20,391 Total investment securities available for sale $ 4,038,239 $ 6,107 $ (57,277 ) $ 3,987,069
Schedule of Unrealized Loss on Investments	Gross unrealized losses on investment securities and the fair value of the related securities, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position, at September 30, 2018 and December 31, 2017 are presented below. September 30, 2018 Less than 12 Months 12 Months or Longer Total (in thousands) Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses U.S. Treasury securities $ 38,352 $ 739 $ 62,905 $ 1,887 $ 101,257 $ 2,626 U.S. Government agency securities 29,727 258 — — 29,727 258 Mortgage-backed securities issued by U.S. Government agencies 15,655 364 73,555 3,761 89,210 4,125 Mortgage-backed securities issued by U.S. Government sponsored enterprises 830,455 24,765 1,618,843 78,767 2,449,298 103,532 Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises 214,420 3,406 903,283 47,269 1,117,703 50,675 Corporate debt and other debt securities — — 1,965 35 1,965 35 Total $ 1,128,609 $ 29,532 $ 2,660,551 $ 131,719 $ 3,789,160 $ 161,251 December 31, 2017 Less than 12 Months 12 Months or Longer Total (in thousands) Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses U.S. Treasury securities $ 34,243 $ 443 $ 29,562 $ 491 $ 63,805 $ 934 Mortgage-backed securities issued by U.S. Government agencies 36,810 357 55,740 1,005 92,550 1,362 Mortgage-backed securities issued by U.S. Government sponsored enterprises 1,271,012 10,263 929,223 21,091 2,200,235 31,354 Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises 653,781 9,497 426,237 13,907 1,080,018 23,404 Corporate debt and other securities — — 5,097 223 5,097 223 Total $ 1,995,846 $ 20,560 $ 1,445,859 $ 36,717 $ 3,441,705 $ 57,277
Amortized Cost and Estimated Fair Value by Contractual Maturity of Investment Securities Available-for-Sale	For purposes of the maturity table, mortgage-backed securities and CMOs, which are not due at a single maturity date, have been classified based on the final contractual maturity date. Distribution of Maturities at September 30, 2018 (in thousands) Within One 1 to 5 5 to 10 More Than Total Amortized Cost U.S. Treasury securities $ 19,382 $ 103,883 $ — $ — $ 123,265 U.S. Government agency securities 1,917 6,118 29,985 — 38,020 Mortgage-backed securities issued by U.S. Government agencies — — 25,659 79,274 104,933 Mortgage-backed securities issued by U.S. Government sponsored enterprises — 43,496 556,115 1,993,216 2,592,827 Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises — — 28,367 1,140,011 1,168,378 Corporate debt and other debt securities — — 15,000 2,000 17,000 Total amortized cost $ 21,299 $ 153,497 $ 655,126 $ 3,214,501 $ 4,044,423 Fair Value U.S. Treasury securities $ 19,382 $ 101,257 $ — $ — $ 120,639 U.S. Government agency securities 1,937 6,200 29,727 — 37,864 Mortgage-backed securities issued by U.S. Government agencies — — 25,154 75,729 100,883 Mortgage-backed securities issued by U.S. Government sponsored enterprises — 42,630 534,881 1,911,854 2,489,365 Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises — — 27,198 1,090,505 1,117,703 Corporate debt and other debt securities — — 15,155 1,965 17,120 Total fair value $ 21,319 $ 150,087 $ 632,115 $ 3,080,053 $ 3,883,574
Schedule of Activity for Available-for-Sale Securities	Proceeds from sales, gross gains, and gross losses on sales of securities available for sale for the three and nine months ended September 30, 2018 and 2017 are presented below. The specific identification method is used to reclassify gains and losses out of other comprehensive income at the time of sale. On January 1, 2018, Synovus transferred $3.2 million , at fair value, from investment securities available for sale to other assets upon adoption of ASU 2016-01. Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Proceeds from sales of investment securities available for sale $ — $ 473,912 $ 35,066 $ 812,293 Gross realized gains on sales — — — 7,942 Gross realized losses on sales — (7,956 ) (1,296 ) (8,231 ) Investment securities losses, net $ — $ (7,956 ) $ (1,296 ) $ (289 )

Loans and Allowance for Loan _2

Loans and Allowance for Loan Losses (Tables)	9 Months Ended
	Sep. 30, 2018
Loans and Allowance for Loan Losses [Abstract]
Schedule of Current, Accruing Past Due, and Nonaccrual Loans	The following is a summary of current, accruing past due, and non-accrual loans by portfolio class as of September 30, 2018 and December 31, 2017 . Current, Accruing Past Due, and Non-accrual Loans September 30, 2018 (in thousands) Current Accruing 30-89 Days Past Due Accruing 90 Days or Greater Past Due Total Accruing Past Due Non-accrual Total Commercial, financial and agricultural $ 7,185,447 $ 25,850 $ 1,159 $ 27,009 $ 69,010 $ 7,281,466 Owner-occupied 5,206,192 8,879 1,049 9,928 5,708 5,221,828 Total commercial and industrial 12,391,639 34,729 2,208 36,937 74,718 12,503,294 Investment properties 5,661,605 1,930 — 1,930 2,155 5,665,690 1-4 family properties 701,406 2,651 — 2,651 3,139 707,196 Land and development 333,709 765 217 982 4,829 339,520 Total commercial real estate 6,696,720 5,346 217 5,563 10,123 6,712,406 Home equity lines 1,442,451 7,819 651 8,470 14,498 1,465,419 Consumer mortgages 2,832,971 4,960 — 4,960 5,313 2,843,244 Credit cards 241,334 2,170 1,645 3,815 — 245,149 Other consumer loans 1,809,033 18,444 135 18,579 3,773 1,831,385 Total consumer 6,325,789 33,393 2,431 35,824 23,584 6,385,197 Total loans $ 25,414,148 $ 73,468 $ 4,856 $ 78,324 $ 108,425 $ 25,600,897 (1 ) December 31, 2017 (in thousands) Current Accruing 30-89 Days Past Due Accruing 90 Days or Greater Past Due Total Accruing Past Due Non-accrual Total Commercial, financial and agricultural $ 7,097,127 $ 11,214 $ 1,016 $ 12,230 $ 70,130 $ 7,179,487 Owner-occupied 4,830,150 6,880 479 7,359 6,654 4,844,163 Total commercial and industrial 11,927,277 18,094 1,495 19,589 76,784 12,023,650 Investment properties 5,663,665 2,506 90 2,596 3,804 5,670,065 1-4 family properties 775,023 3,545 202 3,747 2,849 781,619 Land and development 476,131 1,609 67 1,676 5,797 483,604 Total commercial real estate 6,914,819 7,660 359 8,019 12,450 6,935,288 Home equity lines 1,490,808 5,629 335 5,964 17,455 1,514,227 Consumer mortgages 2,622,061 3,971 268 4,239 7,203 2,633,503 Credit cards 229,015 1,930 1,731 3,661 — 232,676 Other consumer loans 1,461,223 10,333 226 10,559 1,669 1,473,451 Total consumer 5,803,107 21,863 2,560 24,423 26,327 5,853,857 Total loans $ 24,645,203 $ 47,617 $ 4,414 $ 52,031 $ 115,561 $ 24,812,795 (2 ) (1) Total before net deferred fees and costs of $23.8 million . (2) Total before net deferred fees and costs of $25.3 million .
Loan Portfolio Credit Exposure	In the following tables, consumer loans are generally assigned a risk grade similar to the classifications described above; however, upon reaching 90 days and 120 days past due, they are generally downgraded to Substandard and Loss, respectively, in accordance with the FFIEC Uniform Retail Credit Classification and Account Management Policy. Additionally, in accordance with the Interagency Supervisory Guidance on Allowance for Loan and Lease Losses Estimation Practices for Loans and Lines of Credit Secured by Junior Liens on 1-4 Family Residential Properties, the risk grade classifications of home equity lines and consumer mortgages secured by junior liens on 1-4 family residential properties also consider available information on the payment status of any associated senior liens with other financial institutions. Loan Portfolio Credit Exposure by Risk Grade September 30, 2018 (in thousands) Pass Special Substandard (1) Doubtful (2) Loss Total Commercial, financial and agricultural $ 6,986,930 $ 135,359 $ 157,922 $ 1,251 $ 4 (3) $ 7,281,466 Owner-occupied 5,077,397 79,967 64,038 426 — 5,221,828 Total commercial and industrial 12,064,327 215,326 221,960 1,677 4 12,503,294 Investment properties 5,587,389 47,667 30,634 — — 5,665,690 1-4 family properties 687,775 7,943 11,478 — — 707,196 Land and development 298,696 24,661 12,689 3,129 345 (3) 339,520 Total commercial real estate 6,573,860 80,271 54,801 3,129 345 6,712,406 Home equity lines 1,446,606 — 17,513 175 1,125 (3) 1,465,419 Consumer mortgages 2,836,972 — 6,171 101 — 2,843,244 Credit cards 243,503 — 570 — 1,076 (4) 245,149 Other consumer loans 1,827,487 — 3,640 257 1 (3) 1,831,385 Total consumer 6,354,568 — 27,894 533 2,202 6,385,197 Total loans $ 24,992,755 $ 295,597 $ 304,655 $ 5,339 $ 2,551 $ 25,600,897 (5 ) December 31, 2017 (in thousands) Pass Special Substandard (1) Doubtful (2) Loss Total Commercial, financial and agricultural $ 6,929,506 $ 115,912 $ 132,818 $ 1,251 $ — $ 7,179,487 Owner-occupied 4,713,877 50,140 80,073 73 — 4,844,163 Total commercial and industrial 11,643,383 166,052 212,891 1,324 — 12,023,650 Investment properties 5,586,792 64,628 18,645 — — 5,670,065 1-4 family properties 745,299 19,419 16,901 — — 781,619 Land and development 431,759 33,766 14,950 3,129 — 483,604 Total commercial real estate 6,763,850 117,813 50,496 3,129 — 6,935,288 Home equity lines 1,491,105 — 21,079 285 1,758 (3) 1,514,227 Consumer mortgages 2,622,499 — 10,607 291 106 (3) 2,633,503 Credit cards 230,945 — 399 — 1,332 (4) 232,676 Other consumer loans 1,470,944 — 2,168 329 10 (3) 1,473,451 Total consumer 5,815,493 — 34,253 905 3,206 5,853,857 Total loans $ 24,222,726 $ 283,865 $ 297,640 $ 5,358 $ 3,206 $ 24,812,795 (6 ) (1) Includes $204.1 million and $190.6 million of Substandard accruing loans at September 30, 2018 and December 31, 2017 , respectively. (2) The loans within this risk grade are on non-accrual status. Commercial loans generally have an allowance for loan losses in accordance with ASC 310, and retail loans generally have an allowance for loan losses equal to 50% of the loan amount. (3) The loans within this risk grade are on non-accrual status and have an allowance for loan losses equal to the full loan amount. (4) Represent amounts that were 120 days past due. These credits are downgraded to the Loss category with an allowance for loan losses equal to the full loan amount and are generally charged off upon reaching 181 days past due in accordance with the FFIEC Uniform Retail Credit Classification and Account Management Policy. (5) Total before net deferred fees and costs of $23.8 million . (6) Total before net deferred fees and costs of $25.3 million .
Schedule of Allowances for Loan Losses and Recorded Investment in Loans	The following table details the changes in the allowance for loan losses by loan segment for the three and nine months ended September 30, 2018 and 2017 . Allowance for Loan Losses and Recorded Investment in Loans As Of and For The Three Months Ended September 30, 2018 (in thousands) Commercial & Industrial Commercial Real Estate Consumer Total Allowance for loan losses: Beginning balance $ 130,335 $ 75,205 $ 46,185 $ 251,725 Charge-offs (13,526 ) (1,077 ) (3,993 ) (18,596 ) Recoveries 1,091 591 1,657 3,339 Provision for loan losses 11,417 (1,447 ) 5,012 14,982 Ending balance (1) $ 129,317 $ 73,272 $ 48,861 $ 251,450 Ending balance: individually evaluated for impairment $ 9,108 $ 3,317 $ 970 $ 13,395 Ending balance: collectively evaluated for impairment $ 120,209 $ 69,955 $ 47,891 $ 238,055 Loans: Ending balance: total loans (1)(2) $ 12,503,294 $ 6,712,406 $ 6,385,197 $ 25,600,897 Ending balance: individually evaluated for impairment $ 102,671 $ 37,988 $ 28,963 $ 169,622 Ending balance: collectively evaluated for impairment $ 12,400,623 $ 6,674,418 $ 6,356,234 $ 25,431,275 As Of and For The Three Months Ended September 30, 2017 (in thousands) Commercial & Industrial Commercial Real Estate Consumer Total Allowance for loan losses: Beginning balance $ 123,437 $ 77,527 $ 47,131 $ 248,095 Charge-offs (21,855 ) (8,129 ) (14,367 ) (44,351 ) Recoveries 1,899 2,543 1,811 6,253 Provision for loan losses 23,022 6,019 10,645 39,686 Ending balance (1) $ 126,503 $ 77,960 $ 45,220 $ 249,683 Ending balance: individually evaluated for impairment $ 7,360 $ 4,108 $ 783 $ 12,251 Ending balance: collectively evaluated for impairment $ 119,143 $ 73,852 $ 44,437 $ 237,432 Loans: Ending balance: total loans (1)(3) $ 11,727,142 $ 7,226,924 $ 5,557,572 $ 24,511,638 Ending balance: individually evaluated for impairment $ 109,434 $ 64,909 $ 30,132 $ 204,475 Ending balance: collectively evaluated for impairment $ 11,617,708 $ 7,162,015 $ 5,527,440 $ 24,307,163 (1) As of and for the three months ended September 30, 2018 and 2017 , there were no purchased credit-impaired loans and no allowance for loan losses for purchased credit-impaired loans. (2) Total before net deferred fees and costs of $23.8 million . (3) Total before net deferred fees and costs of $24.3 million . Allowance for Loan Losses and Recorded Investment in Loans As Of and For The Nine Months Ended September 30, 2018 (in thousands) Commercial & Industrial Commercial Real Estate Consumer Total Allowance for loan losses: Beginning balance $ 126,803 $ 74,998 $ 47,467 $ 249,268 Charge-offs (37,312 ) (3,523 ) (13,888 ) (54,723 ) Recoveries 5,086 7,555 4,716 17,357 Provision for loan losses 34,740 (5,758 ) 10,566 39,548 Ending balance (1) $ 129,317 $ 73,272 $ 48,861 $ 251,450 Ending balance: individually evaluated for impairment $ 9,108 $ 3,317 $ 970 $ 13,395 Ending balance: collectively evaluated for impairment $ 120,209 $ 69,955 $ 47,891 $ 238,055 Loans: Ending balance: total loans (1)(2) $ 12,503,294 $ 6,712,406 $ 6,385,197 $ 25,600,897 Ending balance: individually evaluated for impairment $ 102,671 $ 37,988 $ 28,963 $ 169,622 Ending balance: collectively evaluated for impairment $ 12,400,623 $ 6,674,418 $ 6,356,234 $ 25,431,275 As Of and For The Nine Months Ended September 30, 2017 (in thousands) Commercial & Industrial Commercial Real Estate Consumer Total Allowance for loan losses: Beginning balance $ 125,778 $ 81,816 $ 44,164 $ 251,758 Charge-offs (41,390 ) (11,336 ) (24,023 ) (76,749 ) Recoveries 5,181 6,191 4,682 16,054 Provision for loan losses 36,934 1,289 20,397 58,620 Ending balance (1) $ 126,503 $ 77,960 $ 45,220 $ 249,683 Ending balance: individually evaluated for impairment $ 7,360 $ 4,108 $ 783 $ 12,251 Ending balance: collectively evaluated for impairment $ 119,143 $ 73,852 $ 44,437 $ 237,432 Loans: Ending balance: total loans (1)(3) $ 11,727,142 $ 7,226,924 $ 5,557,572 $ 24,511,638 Ending balance: individually evaluated for impairment $ 109,434 $ 64,909 $ 30,132 $ 204,475 Ending balance: collectively evaluated for impairment $ 11,617,708 $ 7,162,015 $ 5,527,440 $ 24,307,163 (1) As of and for the nine months ended September 30, 2018 and 2017 , there were no purchased credit-impaired loans and no allowance for loan losses for purchased credit-impaired loans. (2) Total before net deferred fees and costs of $23.8 million . (3) Total before net deferred fees and costs of $24.3 million .
Schedule of Impaired Loans	The tables below summarize impaired loans (including accruing TDRs) as of September 30, 2018 and December 31, 2017 . Impaired Loans (including accruing TDRs) September 30, 2018 Three Months Ended September 30, 2018 Nine Months Ended September 30, 2018 (in thousands) Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized With no related allowance recorded Commercial, financial and agricultural $ 20,884 $ 26,878 $ — $ 21,118 $ — $ 14,458 $ — Owner-occupied — — — — — — — Total commercial and industrial 20,884 26,878 — 21,118 — 14,458 — Investment properties — — — — — — — 1-4 family properties — — — — — — — Land and development 265 1,110 — 88 — 42 — Total commercial real estate 265 1,110 — 88 — 42 — Home equity lines — — — — — 949 — Consumer mortgages 33 60 — 42 — 901 — Credit cards — — — — — — — Other consumer loans — — — — — — — Total consumer 33 60 — 42 — 1,850 — Total impaired loans with no related allowance recorded $ 21,182 $ 28,048 $ — $ 21,248 $ — $ 16,350 $ — With allowance recorded Commercial, financial and agricultural $ 35,181 $ 36,127 $ 6,024 $ 40,136 $ 143 $ 55,088 $ 571 Owner-occupied 46,606 47,292 3,084 44,366 435 40,171 1,165 Total commercial and industrial 81,787 83,419 9,108 84,502 578 95,259 1,736 Investment properties 13,846 13,846 1,566 14,103 179 20,437 597 1-4 family properties 8,307 8,307 191 9,697 176 10,876 619 Land and development 15,570 17,311 1,560 16,734 61 17,765 211 Total commercial real estate 37,723 39,464 3,317 40,534 416 49,078 1,427 Home equity lines 3,209 3,223 236 3,433 20 3,693 96 Consumer mortgages 20,201 20,201 575 19,924 225 19,496 618 Credit cards — — — — — — — Other consumer loans 5,520 5,520 159 5,284 69 5,220 212 Total consumer 28,930 28,944 970 28,641 314 28,409 926 Total impaired loans with allowance recorded $ 148,440 $ 151,827 $ 13,395 $ 153,677 $ 1,308 $ 172,746 $ 4,089 Total impaired loans Commercial, financial and agricultural $ 56,065 $ 63,005 $ 6,024 $ 61,254 $ 143 $ 69,546 $ 571 Owner-occupied 46,606 47,292 3,084 44,366 435 40,171 1,165 Total commercial and industrial 102,671 110,297 9,108 105,620 578 109,717 1,736 Investment properties 13,846 13,846 1,566 14,103 179 20,437 597 1-4 family properties 8,307 8,307 191 9,697 176 10,876 619 Land and development 15,835 18,421 1,560 16,822 61 17,807 211 Total commercial real estate 37,988 40,574 3,317 40,622 416 49,120 1,427 Home equity lines 3,209 3,223 236 3,433 20 4,642 96 Consumer mortgages 20,234 20,261 575 19,966 225 20,397 618 Credit cards — — — — — — — Other consumer loans 5,520 5,520 159 5,284 69 5,220 212 Total consumer 28,963 29,004 970 28,683 314 30,259 926 Total impaired loans $ 169,622 $ 179,875 $ 13,395 $ 174,925 $ 1,308 $ 189,096 $ 4,089 Impaired Loans (including accruing TDRs) December 31, 2017 Year Ended December 31, 2017 (in thousands) Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized With no related allowance recorded Commercial, financial and agricultural $ 8,220 $ 9,576 $ — $ 21,686 $ — Owner-occupied — — — 6,665 — Total commercial and industrial 8,220 9,576 — 28,351 — Investment properties — — — 123 — 1-4 family properties — — — 323 — Land and development 56 1,740 — 1,816 — Total commercial real estate 56 1,740 — 2,262 — Home equity lines 2,746 2,943 — 1,205 — Consumer mortgages — — — 496 — Credit cards — — — — — Other consumer loans — — — — — Total consumer 2,746 2,943 — 1,701 — Total impaired loans with no related allowance recorded $ 11,022 $ 14,259 $ — $ 32,314 $ — With allowance recorded Commercial, financial and agricultural $ 65,715 $ 65,851 $ 7,406 $ 50,468 $ 1,610 Owner-occupied 37,399 37,441 2,109 40,498 1,382 Total commercial and industrial 103,114 103,292 9,515 90,966 2,992 Investment properties 23,364 23,364 1,100 28,749 1,144 1-4 family properties 15,056 15,056 504 16,257 925 Land and development 18,420 18,476 2,636 23,338 404 Total commercial real estate 56,840 56,896 4,240 68,344 2,473 Home equity lines 5,096 5,096 114 7,476 334 Consumer mortgages 18,668 18,668 569 19,144 896 Credit cards — — — — — Other consumer loans 5,546 5,546 470 4,765 266 Total consumer 29,310 29,310 1,153 31,385 1,496 Total impaired loans with allowance recorded $ 189,264 $ 189,498 $ 14,908 $ 190,695 $ 6,961 Total impaired loans Commercial, financial and agricultural $ 73,935 $ 75,427 $ 7,406 $ 72,154 $ 1,610 Owner-occupied 37,399 37,441 2,109 47,163 1,382 Total commercial and industrial 111,334 112,868 9,515 119,317 2,992 Investment properties 23,364 23,364 1,100 28,872 1,144 1-4 family properties 15,056 15,056 504 16,580 925 Land and development 18,476 20,216 2,636 25,154 404 Total commercial real estate 56,896 58,636 4,240 70,606 2,473 Home equity lines 7,842 8,039 114 8,681 334 Consumer mortgages 18,668 18,668 569 19,640 896 Credit cards — — — — — Other consumer loans 5,546 5,546 470 4,765 266 Total consumer 32,056 32,253 1,153 33,086 1,496 Total impaired loans $ 200,286 $ 203,757 $ 14,908 $ 223,009 $ 6,961
Troubled Debt Restructurings	The following tables represent, by concession type, the post-modification balance for loans modified or renewed during the three and nine months ended September 30, 2018 and 2017 that were reported as accruing or non-accruing TDRs. TDRs by Concession Type Three Months Ended September 30, 2018 (in thousands, except contract data) Number of Contracts Principal Forgiveness Below Market Interest Rate Term Extensions and/or Other Concessions Total Commercial, financial and agricultural 7 $ — $ — $ 565 $ 565 Owner-occupied 3 — 727 4,839 5,566 Total commercial and industrial 10 — 727 5,404 6,131 Investment properties 1 — 42 — 42 1-4 family properties 5 — 445 766 1,211 Land and development 1 — — 71 71 Total commercial real estate 7 — 487 837 1,324 Home equity lines 1 — — 191 191 Consumer mortgages 2 — 670 — 670 Credit cards — — — — — Other consumer loans 44 — 695 2,784 3,479 Total consumer 47 — 1,365 2,975 4,340 Total TDRs 64 $ — $ 2,579 $ 9,216 $ 11,795 (1 ) Nine Months Ended September 30, 2018 (in thousands, except contract data) Number of Contracts Principal Forgiveness Below Market Interest Rate Term Extensions and/or Other Concessions Total Commercial, financial and agricultural 21 $ — $ — $ 2,130 $ 2,130 Owner-occupied 9 — 5,526 5,523 11,049 Total commercial and industrial 30 — 5,526 7,653 13,179 Investment properties 4 — 6,053 2,215 8,268 1-4 family properties 12 — 1,408 1,259 2,667 Land and development 4 — — 1,856 1,856 Total commercial real estate 20 — 7,461 5,330 12,791 Home equity lines 4 — 172 339 511 Consumer mortgages 16 — 5,365 87 5,452 Credit cards — — — — — Other consumer loans 75 — 1,621 3,606 5,227 Total consumer 95 — 7,158 4,032 11,190 Total TDRs 145 $ — $ 20,145 $ 17,015 $ 37,160 (1 ) (1) Net charge-offs of $88 thousand were recorded during both the three and nine months ended September 30, 2018 upon restructuring of these loans. TDRs by Concession Type Three Months Ended September 30, 2017 (in thousands, except contract data) Number of Contracts Principal Forgiveness Below Market Interest Rate Term Extensions and/or Other Concessions Total Commercial, financial and agricultural 22 $ — $ 2,943 $ 5,866 $ 8,809 Owner-occupied 3 — 35 1,683 1,718 Total commercial and industrial 25 — 2,978 7,549 10,527 Investment properties — — — — — 1-4 family properties 5 — — 964 964 Land and development 3 — 157 760 917 Total commercial real estate 8 — 157 1,724 1,881 Home equity lines — — — — — Consumer mortgages 7 — 248 1,181 1,429 Credit cards — — — — — Other consumer loans 17 — 682 388 1,070 Total consumer 24 — 930 1,569 2,499 Total TDRs 57 $ — $ 4,065 $ 10,842 $ 14,907 (2 ) Nine Months Ended September 30, 2017 (in thousands, except contract data) Number of Contracts Principal Forgiveness Below Market Interest Rate Term Extensions and/or Other Concessions Total Commercial, financial and agricultural 50 $ — $ 8,703 $ 12,145 $ 20,848 Owner-occupied 4 — 35 1,705 1,740 Total commercial and industrial 54 — 8,738 13,850 22,588 Investment properties — — — — — 1-4 family properties 21 — 2,090 1,477 3,567 Land and development 4 — 157 895 1,052 Total commercial real estate 25 — 2,247 2,372 4,619 Home equity lines — — — — — Consumer mortgages 8 — 248 1,190 1,438 Credit cards — — — — — Other consumer loans 25 — 682 958 1,640 Total consumer 33 — 930 2,148 3,078 Total TDRs 112 $ — $ 11,915 $ 18,370 $ 30,285 (2 ) (2) No net charge-offs were recorded during the three and nine months ended September 30, 2017 upon restructuring of these loans.

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Loss) (Tables)	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Schedule of Changes in Accumulated Other Comprehensive Income (Loss) by Component (Net of Income Taxes)	The following tables illustrate activity within the balances in accumulated other comprehensive income (loss) by component for the three and nine months ended September 30, 2018 and 2017 . Changes in Accumulated Other Comprehensive Income (Loss) by Component (Net of Income Taxes) (in thousands) Net unrealized losses on cash flow hedges Net unrealized gains (losses) on investment securities available for sale Post-retirement unfunded health benefit Total Balance as of July 1, 2018 $ (12,137 ) $ (114,565 ) $ 982 $ (125,720 ) Other comprehensive loss before reclassifications — (17,940 ) (34 ) (17,974 ) Amounts reclassified from accumulated other comprehensive income (loss) — — (26 ) (26 ) Net current period other comprehensive loss — (17,940 ) (60 ) (18,000 ) Balance as of September 30, 2018 $ (12,137 ) $ (132,505 ) $ 922 $ (143,720 ) Balance as of July 1, 2017 $ (12,137 ) $ (36,586 ) $ 858 $ (47,865 ) Other comprehensive income before reclassifications — 3,359 38 3,397 Amounts reclassified from accumulated other comprehensive income (loss) — 4,893 (21 ) 4,872 Net current period other comprehensive income — 8,252 17 8,269 Balance as of September 30, 2017 $ (12,137 ) $ (28,334 ) $ 875 $ (39,596 ) (in thousands) Net unrealized gains (losses) on cash flow hedges Net unrealized gains (losses) on investment securities available for sale Post-retirement unfunded health benefit Total Balance at December 31, 2017 $ (12,137 ) $ (43,470 ) $ 853 $ (54,754 ) Other comprehensive loss before reclassifications — (82,349 ) (34 ) (82,383 ) Amounts reclassified from accumulated other comprehensive income (loss) — 960 (72 ) 888 Net current period other comprehensive loss — (81,389 ) (106 ) (81,495 ) Reclassification from adoption of ASU 2018-02 — (7,763 ) 175 (7,588 ) Cumulative-effect adjustment from adoption of ASU 2016-01 — 117 — 117 Balance as of September 30, 2018 $ (12,137 ) $ (132,505 ) $ 922 $ (143,720 ) Balance at December 31, 2016 $ (12,217 ) $ (44,324 ) $ 882 $ (55,659 ) Other comprehensive income before reclassifications — 15,812 38 15,850 Amounts reclassified from accumulated other comprehensive income (loss) 80 178 (45 ) 213 Net current period other comprehensive income 80 15,990 (7 ) 16,063 Balance as of September 30, 2017 $ (12,137 ) $ (28,334 ) $ 875 $ (39,596 )

Fair Value Accounting (Tables)

Fair Value Accounting (Tables)	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Financial Instruments Measured at Fair Value on Recurring Basis	The following tables present all financial instruments measured at fair value on a recurring basis as of September 30, 2018 and December 31, 2017 . September 30, 2018 (in thousands) Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Assets and Liabilities at Fair Value Assets Trading securities: U.S. Government agency securities $ — $ 6,532 $ — $ 6,532 Mortgage-backed securities issued by U.S. Government agencies — 921 — 921 Collateralized mortgage obligations issued by U.S. Government sponsored enterprises — 183 — 183 State and municipal securities — 177 — 177 Other investments 998 38 — 1,036 Total trading securities $ 998 $ 7,851 $ — $ 8,849 Mortgage loans held for sale — 37,276 — 37,276 Investment securities available for sale: U.S. Treasury securities $ 120,639 $ — $ — $ 120,639 U.S. Government agency securities — 37,864 — 37,864 Mortgage-backed securities issued by U.S. Government agencies — 100,883 — 100,883 Mortgage-backed securities issued by U.S. Government sponsored enterprises — 2,489,365 — 2,489,365 Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises — 1,117,703 — 1,117,703 Corporate debt and other debt securities — 15,155 1,965 17,120 Total investment securities available for sale $ 120,639 $ 3,760,970 $ 1,965 $ 3,883,574 Private equity investments — — 13,112 13,112 Mutual funds 3,118 — — 3,118 Mutual funds held in rabbi trusts 14,100 — — 14,100 GGL/SBA loans servicing asset — — 3,761 3,761 Derivative assets: Interest rate contracts $ — $ 8,892 $ — $ 8,892 Mortgage derivatives (1) — 1,122 — 1,122 Total derivative assets $ — $ 10,014 $ — $ 10,014 Liabilities Trading account liabilities — 3,540 — 3,540 Earnout liability (2) — — 23,000 23,000 Derivative liabilities: Interest rate contracts $ — $ 20,822 $ — 20,822 Visa derivative — — 1,990 1,990 Total derivative liabilities $ — $ 20,822 $ 1,990 $ 22,812 December 31, 2017 (in thousands) Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Assets and Liabilities at Fair Value Assets Trading securities: Mortgage-backed securities issued by U.S. Government agencies $ — $ 3,002 $ — $ 3,002 Collateralized mortgage obligations issued by U.S. Government sponsored enterprises — 296 — 296 Other investments 522 — — 522 Total trading securities $ 522 $ 3,298 $ — $ 3,820 Mortgage loans held for sale — 48,024 — 48,024 Investment securities available for sale: U.S. Treasury securities $ 82,674 $ — $ — $ 82,674 U.S. Government agency securities — 10,862 — 10,862 Mortgage-backed securities issued by U.S. Government agencies — 120,440 — 120,440 Mortgage-backed securities issued by U.S. Government sponsored enterprises — 2,640,523 — 2,640,523 Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises — 1,111,999 — 1,111,999 State and municipal securities — 180 — 180 Corporate debt and other securities 3,162 15,294 1,935 20,391 Total investment securities available for sale $ 85,836 $ 3,899,298 $ 1,935 $ 3,987,069 Private equity investments — — 15,771 15,771 Mutual funds held in rabbi trusts 14,140 — — 14,140 GGL/SBA loan servicing asset — — 4,101 4,101 Derivative assets: Interest rate contracts $ — $ 10,786 $ — $ 10,786 Mortgage derivatives (1) — 936 — 936 Total derivative assets $ — $ 11,722 $ — $ 11,722 Liabilities Trading account liabilities — 1,000 — 1,000 Earnout liability (2) — — 11,348 11,348 Derivative liabilities: Interest rate contracts $ — $ 12,638 $ — $ 12,638 Mortgage derivatives (1) — 129 — 129 Visa derivative — — 4,330 4,330 Total derivative liabilities $ — $ 12,767 $ 4,330 $ 17,097 (1) Mortgage derivatives consist of customer interest rate lock commitments that relate to the potential origination of mortgage loans, which would be classified as held for sale and forward loan sales commitments with third-party investors. (2) Earnout liability consists of contingent consideration obligation related to the Global One acquisition.
Changes in Fair Value Included in Consolidated Statements of Income	The following table summarizes the difference between the fair value and the unpaid principal balance of mortgage loans held for sale measured at fair value and the changes in fair value of these loans. Mortgage loans held for sale are initially measured at fair value with subsequent changes in fair value recognized in earnings. Changes in fair value are recorded as a component of mortgage banking income in the consolidated statements of income. An immaterial portion of these changes in fair value was attributable to changes in instrument-specific credit risk. Changes in Fair Value Included in Net Income For the Three Months Ended September 30, For the Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Mortgage loans held for sale $ (569 ) $ (104 ) $ (414 ) $ 850 Mortgage Loans Held for Sale (in thousands) As of September 30, 2018 As of December 31, 2017 Fair value $ 37,276 $ 48,024 Unpaid principal balance 36,505 46,839 Fair value less aggregate unpaid principal balance $ 771 $ 1,185
Changes in Level 3 Fair Value Measurements	Three Months Ended September 30, 2018 (in thousands) Investment Securities Available for Sale Private Equity Investments GGL / SBA Loans Servicing Asset Earnout Visa Derivative Beginning balance, July 1, 2018 $ 1,857 $ 12,678 $ 4,186 $ (11,348 ) $ (5,943 ) Total (losses) gains realized/unrealized: Included in earnings — 434 (561 ) (11,652 ) — Unrealized gains (losses) included in OCI 108 — — — — Additions — — 136 — — Settlements — — — — 3,953 Ending balance, September 30, 2018 $ 1,965 $ 13,112 $ 3,761 $ (23,000 ) $ (1,990 ) Total net losses for the period included in earnings attributable to the change in unrealized losses relating to assets/liabilities still held at September 30, 2018 $ — $ 434 $ (561 ) $ (11,652 ) $ — Three Months Ended September 30, 2017 (in thousands) Investment Securities Available for Sale Private Equity Investments GGL / SBA Earnout Visa Derivative Beginning balance, July 1, 2017 $ 1,927 $ 15,698 $ 4,297 $ (13,941 ) $ (5,053 ) Total (losses) gains realized/unrealized: Included in earnings — (27 ) (27 ) (2,059 ) — Unrealized gains (losses) included in OCI (9 ) — — — — Settlements — — — — 360 Ending balance, September 30, 2017 $ 1,918 $ 15,671 $ 4,270 $ (16,000 ) $ (4,693 ) Total net losses for the period included in earnings attributable to the change in unrealized losses relating to assets/liabilities still held at September 30, 2017 $ — $ (27 ) $ (27 ) $ (2,059 ) $ — Nine Months Ended September 30, 2018 (in thousands) Investment Securities Available for Sale Private Equity Investments GGL / SBA Earnout Visa Derivative Beginning balance, January 1, 2018 $ 1,935 $ 15,771 $ 4,101 $ (11,348 ) $ (4,330 ) Total (losses) gains realized/unrealized: Included in earnings — (2,659 ) (1,295 ) (11,652 ) (2,328 ) Unrealized gains (losses) included in OCI 30 — — — — Additions — — 955 — — Settlements — — — — 4,668 Ending balance, September 30, 2018 $ 1,965 $ 13,112 $ 3,761 $ (23,000 ) $ (1,990 ) Total net losses for the period included in earnings attributable to the change in unrealized losses relating to assets/liabilities still held at September 30, 2018 $ — $ (2,659 ) $ (1,295 ) $ (11,652 ) $ (2,328 ) Nine Months Ended September 30, 2017 (in thousands) Investment Securities Available for Sale Private Equity Investments GGL / SBA Loans Servicing Asset Earnout Liability Visa Derivative Beginning balance, January 1, 2017 $ 1,796 $ 25,493 $ — $ (14,000 ) $ (5,768 ) Total (losses) gains realized/unrealized: Included in earnings — (3,193 ) (721 ) (3,766 ) — Unrealized gains (losses) included in OCI 122 — — — — Additions — — 539 — — Sales and settlements — (6,629 ) — — 1,075 Transfer from amortization method to fair value — — 4,452 — — Measurement period adjustments related to Global One — — — 1,766 — Ending balance, September 30, 2017 $ 1,918 $ 15,671 $ 4,270 $ (16,000 ) $ (4,693 ) Total net losses for the period included in earnings attributable to the change in unrealized losses relating to assets/liabilities still held at September 30, 2017 $ — $ (3,193 ) $ (721 ) $ (3,766 ) $ —
Fair Value Inputs, Assets, Quantitative Information	September 30, 2018 December 31, 2017 Assets and liabilities measured at fair value on a recurring basis Valuation Technique Significant Unobservable Input Level 3 Fair Value Range or Weighted Average Level 3 Fair Value Range or Weighted Average Investment Securities Available for Sale - Other Investments: Trust preferred securities Discounted cash flow analysis Credit spread embedded in discount rate $1,965 389 bps $1,935 398 bps Private equity investments Individual analysis of each investee company Multiple factors, including but not limited to, current operations, financial condition, cash flows, evaluation of business management and financial plans, and recently executed financing transactions related to the investee companies 13,112 N/A 15,771 N/A GGL/SBA loans servicing asset Discounted cash flow analysis Discount rate Prepayment speeds 3,761 13.40% 8.64% 4,101 13.16% 7.50% Earnout liability Option pricing methods and Monte Carlo simulation Earning projections of Global One 23,000 N/A 11,348 N/A Visa derivative liability Discounted cash flow analysis Estimated timing of resolution of covered litigation, future cumulative deposits to the litigation escrow for settlement of the covered litigation, and estimated future monthly fees payable to the derivative counterparty 1,990 1-2 years 4,330 1-4 years September 30, 2018 December 31, 2017 Assets measured at fair value on a non-recurring basis Valuation Technique Significant Unobservable Input Range (Weighted Average) (1) Range (Weighted Average) (1) Collateral dependent impaired loans Third-party appraised value of collateral less estimated selling costs Discount to appraised value Estimated selling costs 0% - 68% (25%) 0% - 10% (7%) 0%-50% (15%) 0%-10% (7%) Other loans held for sale Third-party appraised value of collateral less estimated selling costs Discount to appraised value Estimated selling costs N/A N/A 5% - 99% (54%) 0% - 10% (2%) Other real estate Third-party appraised value of real estate less estimated selling costs Discount to appraised value Estimated selling costs 0% - 7% (4%) 0% - 10% (7%) 0%-85% (35%) 0%-10% (7%) Other assets held for sale Third-party appraised value less estimated selling costs or BOV Discount to appraised value Estimated selling costs 0%-42% (42%) 0%-10% (7%) 21%-52% (25%) 0%-10% (7%) (1) The range represents management's estimate of the high and low of the value that would be assigned to a particular input. For assets measured at fair value on a non-recurring basis, the weighted average is the measure of central tendencies; it is not the value that management is using for the asset or liability.
Assets and Liabilities Measured at Fair Value on Non-Recurring Basis	The following table presents assets measured at fair value on a non-recurring basis as of the dates indicated for which there was a fair value adjustment during the nine months ended September 30, 2018 and year ended December 31, 2017 . September 30, 2018 December 31, 2017 (in thousands) Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Impaired loans (1) $ — $ — $ 17,270 $ 17,270 $ — $ — $ 3,603 $ 3,603 Other loans held for sale — — — — — — 10,197 10,197 Other real estate — — 507 507 — — 3,363 3,363 Other assets held for sale — — 302 302 — — 5,334 5,334 (1) Collateral-dependent impaired loans that were written down to fair value during the period.
Assets Measured at Fair Value on a Nonrecurring Basis	The following table presents fair value adjustments recognized in earnings for the three and nine months ended September 30, 2018 and 2017 for assets measured at fair value on a non-recurring basis still held at period-end. Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Impaired loans (1) $ 1,223 $ 83 $ 4,594 $ 1,075 Other loans held for sale — 25,051 — 25,051 Other real estate 61 5,165 61 5,165 Other assets held for sale — 1,683 499 1,683 (1) Collateral-dependent impaired loans that were written down to fair value during the period.
Carrying and Estimated Fair Values of Financial Instruments Carried on Balance Sheet	The following tables present the carrying and fair values of financial instruments, as well as the level within the fair value value hierarchy, at September 30, 2018 and December 31, 2017 . The fair values represent management’s estimates based on various methodologies and assumptions. For financial instruments that are not recorded at fair value on the balance sheet, such as loans held for investment, interest-bearing deposits, and long-term debt, the fair value amounts should not be taken as an estimate of the amount that would be realized if all such financial instruments were to be settled immediately. September 30, 2018 (in thousands) Carrying Value Fair Value Level 1 Level 2 Level 3 Financial assets Total cash, cash equivalents, restricted cash, and restricted cash equivalents $ 1,011,933 $ 1,011,933 $ 1,011,933 $ — $ — Trading account assets 8,849 8,849 998 7,851 — Mortgage loans held for sale 37,276 37,276 — 37,276 — Other loans held for sale 12 12 — — 12 Investment securities available for sale 3,883,574 3,883,574 120,639 3,760,970 1,965 Private equity investments 13,112 13,112 — — 13,112 Mutual funds 3,118 3,118 3,118 — — Mutual funds held in rabbi trusts 14,100 14,100 14,100 — — Loans, net 25,325,666 25,138,896 — — 25,138,896 GGL/SBA loans servicing asset 3,761 3,761 — — 3,761 Derivative assets 10,014 10,014 — 10,014 — Financial liabilities Trading account liabilities 3,540 3,540 — 3,540 — Non-interest bearing deposits $ 7,628,736 $ 7,628,736 $ — $ 7,628,736 $ — Non-time interest-bearing deposits 13,847,104 13,847,104 — 13,847,104 — Time deposits 4,957,818 4,937,216 — 4,937,216 — Total deposits $ 26,433,658 $ 26,413,056 $ — $ 26,413,056 $ — Federal funds purchased and securities sold under repurchase agreements 191,145 191,145 191,145 — — Other short-term borrowings 475,000 475,000 — 475,000 — Long-term debt 1,656,909 1,654,002 — 1,654,002 — Earnout liabilities 23,000 23,000 — — 23,000 Derivative liabilities $ 22,812 $ 22,812 $ — $ 20,822 $ 1,990 December 31, 2017 (in thousands) Carrying Value Fair Value Level 1 Level 2 Level 3 Financial assets Total cash, cash equivalents, restricted cash, and restricted cash equivalents $ 932,933 $ 932,933 $ 932,933 $ — $ — Trading account assets 3,820 3,820 522 3,298 — Mortgage loans held for sale 48,024 48,024 — 48,024 — Other loans for sale 11,356 11,356 11,356 Investment securities available for sale 3,987,069 3,987,069 85,836 3,899,298 1,935 Private equity investments 15,771 15,771 — — 15,771 Mutual funds held in rabbi trusts 14,140 14,140 14,140 — — Loans, net 24,538,196 24,507,141 — — 24,507,141 GGL/SBA loans servicing asset 4,101 4,101 — — 4,101 Derivative assets 11,722 11,722 — 11,722 — Financial liabilities Trading account liabilities 1,000 1,000 — 1,000 — Non-interest-bearing deposits $ 7,686,339 $ 7,686,339 $ — $ 7,686,339 $ — Non-time interest-bearing deposits 13,941,814 13,941,814 — 13,941,814 — Time deposits 4,519,747 4,523,661 — 4,523,661 — Total deposits $ 26,147,900 $ 26,151,814 $ — $ 26,151,814 $ — Federal funds purchased and securities sold under repurchase agreements 161,190 161,190 161,190 — — Other short-term borrowings 100,000 100,000 — 100,000 — Long-term debt 1,606,138 1,621,814 — 1,621,814 — Earnout liabilities 11,348 11,348 — — 11,348 Derivative liabilities $ 17,097 $ 17,097 $ — $ 12,767 $ 4,330

Derivative Instruments (Tables)

Derivative Instruments (Tables)	9 Months Ended
	Sep. 30, 2018
Summary of Derivative Instruments [Abstract]
Impact of Derivatives on Balance Sheet	The following table reflects the notional amount and fair value of derivative instruments included on the consolidated balance sheets. September 30, 2018 December 31, 2017 Fair Value Fair Value (in thousands) Notional Amount Derivative Assets (1) Derivative Liabilities (2) Notional Amount Derivative Assets (1) Derivative Liabilities (2) Derivatives not designated Interest rate contracts (3) $ 1,667,397 $ 8,892 $ 20,822 $ 1,466,059 10,786 $ 12,638 Mortgage derivatives - interest rate lock commitments 59,289 875 — 49,304 936 — Mortgage derivatives - forward commitments to sell fixed-rate mortgage loans 85,500 247 — 72,500 — 129 Visa derivative — — 1,990 — — 4,330 Total derivatives not designated as hedging instruments $ 10,014 $ 22,812 $ 11,722 $ 17,097 (1) Derivative assets are recorded in other assets on the consolidated balance sheets. (2) Derivative liabilities are recorded in other liabilities on the consolidated balance sheets. (3) Includes interest rate contracts for customer swaps and offsetting positions, net of variation margin payments.
Effect of Fair Value Hedges on Consolidated Statements of Income	The pre-tax effect of changes in fair value from derivative instruments not designated as hedging instruments on the consolidated statements of income for the three and nine months ended September 30, 2018 and 2017 is presented below. Gain (Loss) Recognized in Consolidated Statements of Income Three Months Ended September 30, Nine Months Ended September 30, (in thousands) Location in Consolidated Statements of Income 2018 2017 2018 2017 Derivatives not designated as hedging instruments: Interest rate contracts (1) Other non-interest income $ 1 $ (4 ) $ (8 ) $ (5 ) Mortgage derivatives - interest rate lock commitments Mortgage banking income (427 ) (180 ) (61 ) (595 ) Mortgage derivatives - forward commitments to sell fixed-rate mortgage loans Mortgage banking income 495 (271 ) 376 (1,929 ) Visa derivative Other non-interest expense — — (2,328 ) — Total $ 69 $ (455 ) $ (2,021 ) $ (2,529 ) (1) Gain (loss) represents net fair value adjustments (including credit-related adjustments) for customer swaps and offsetting positions.

Net Income Per Common Share (Ta

Net Income Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Schedule of Basic And Diluted Earnings per Share	The following table displays a reconciliation of the information used in calculating basic and diluted earnings per common share for the three and nine months ended September 30, 2018 and 2017 . Three Months Ended September 30, Nine Months Ended September 30, (in thousands, except per share data) 2018 2017 2018 2017 Basic Net Income Per Common Share: Net income available to common shareholders $ 99,330 $ 95,448 $ 308,559 $ 238,190 Weighted average common shares outstanding 117,241 120,900 118,096 121,796 Net income per common share, basic $ 0.85 $ 0.79 $ 2.61 $ 1.96 Diluted Net Income Per Common Share: Net income available to common shareholders $ 99,330 $ 95,448 $ 308,559 $ 238,190 Weighted average common shares outstanding 117,241 120,900 118,096 121,796 Potentially dilutive shares from outstanding equity-based awards and earnout payments 854 914 751 832 Weighted average diluted common shares 118,095 121,814 118,847 122,628 Net income per common share, diluted $ 0.84 $ 0.78 $ 2.60 $ 1.94

Income Taxes (Tables)

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Schedule of Provision for Income Tax and Effective Tax Rate	Synovus' provision for income taxes for the three and nine months ended September 30, 2018 and 2017 is based on the estimated annual effective tax rate, plus discrete items. The following table presents the provision for income taxes and the effective tax rates for the periods indicated. Three Months Ended September 30, Nine Months Ended September 30, (dollars in thousands) 2018 2017 2018 2017 Income before income tax expense $ 128,008 $ 152,675 $ 403,502 $ 376,171 Income tax expense 18,949 54,668 80,095 130,303 Effective tax rate 14.8 % 35.8 % 19.8 % 34.6 %

Non-interest Income (Tables)

Non-interest Income (Tables)	9 Months Ended
	Sep. 30, 2018
Revenue from Contract with Customer [Abstract]
Schedule of Non-interest Income	The following table reflects revenue disaggregated by revenue type and line of business for the three and nine months ended September 30, 2018 and 2017 . Non-interest Income by Line of Business For the Three Months Ended September 30, 2018 (in thousands) Community Banking Corporate Banking Retail Banking Financial Management Services Other Total Service charges on deposit accounts $ 5,660 $ 475 $ 13,792 $ — $ 655 $ 20,582 Fiduciary and asset management fees — — — 13,462 — 13,462 Card fees 208 — 10,400 — — 10,608 Brokerage revenue — — — 9,329 — 9,329 Insurance revenue — — — 1,148 — 1,148 Other fees — — 454 — 266 720 $ 5,868 $ 475 $ 24,646 $ 23,939 $ 921 $ 55,849 Other revenues (1) 1,142 1,836 1,645 5,994 5,202 15,819 Total non-interest income $ 7,010 $ 2,311 $ 26,291 $ 29,933 $ 6,123 $ 71,668 For the Three Months Ended September 30, 2017 (in thousands) Community Banking Corporate Banking Retail Banking Financial Management Services Other Total Service charges on deposit accounts $ 5,613 $ 432 $ 14,024 $ — $ 609 $ 20,678 Fiduciary and asset management fees — — — 12,615 — 12,615 Card fees 210 — 9,519 — — 9,729 Brokerage revenue — — — 7,511 — 7,511 Insurance revenue — — — 1,059 — 1,059 Other fees — — 463 — 265 728 $ 5,823 $ 432 $ 24,006 $ 21,185 $ 874 $ 52,320 Other revenues (1) 2,642 1,460 1,574 6,558 70,881 83,115 Total non-interest income $ 8,465 $ 1,892 $ 25,580 $ 27,743 $ 71,755 $ 135,435 ( 1) Other revenues primarily relate to revenues not derived from contracts with customers. Non-interest Income by Line of Business For the Nine Months Ended September 30, 2018 (in thousands) Community Banking Corporate Banking Retail Banking Financial Management Services Other Total Service charges on deposit accounts $ 17,064 $ 1,460 $ 40,310 $ — $ 1,687 $ 60,521 Fiduciary and asset management fees — — — 40,881 — 40,881 Card fees 628 — 31,012 — — 31,640 Brokerage revenue — — — 26,924 — 26,924 Insurance revenue — — — 4,240 — 4,240 Other fees — — 1,487 — 821 2,308 $ 17,692 $ 1,460 $ 72,809 $ 72,045 $ 2,508 $ 166,514 Other revenues (1) 6,983 5,417 4,887 17,402 10,898 45,587 Total non-interest income $ 24,675 $ 6,877 $ 77,696 $ 89,447 $ 13,406 $ 212,101 For the Nine Months Ended September 30, 2017 (in thousands) Community Banking Corporate Banking Retail Banking Financial Management Services Other Total Service charges on deposit accounts $ 17,028 $ 1,319 $ 40,994 $ — $ 1,707 $ 61,048 Fiduciary and asset management fees — — — 37,290 — 37,290 Card fees 647 — 28,967 — — 29,614 Brokerage revenue — — — 21,947 — 21,947 Insurance revenue — — — 3,424 — 3,424 Other fees — — 1,525 — 795 2,320 $ 17,675 $ 1,319 $ 71,486 $ 62,661 $ 2,502 $ 155,643 Other revenues (1) 7,283 5,836 4,756 19,971 82,485 120,331 Total non-interest income $ 24,958 $ 7,155 $ 76,242 $ 82,632 $ 84,987 $ 275,974 ( 1) Other revenues primarily relate to revenues not derived from contracts with customers.

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Loan Commitments and Letters of Credit	Unfunded letters of credit and lending commitments at September 30, 2018 and December 31, 2017 are presented below. (in thousands) September 30, 2018 December 31, 2017 Letters of credit* $ 167,969 $ 153,372 Commitments to fund commercial and industrial loans 5,688,192 5,090,827 Commitments to fund commercial real estate, construction, and land development loans 1,763,006 1,567,583 Commitments under home equity lines of credit 1,211,861 1,137,714 Unused credit card lines 766,521 779,254 Other loan commitments 394,428 351,358 Total unfunded lending commitments and letters of credit $ 9,991,977 $ 9,080,108 * Represent the contractual amount net of risk participations of approximately $70 million and $77 million at September 30, 2018 and December 31, 2017 , respectively.

Basis of Presentation (Details)

Basis of Presentation (Details) $ in Thousands	Jan. 01, 2018USD ($)	Dec. 31, 2017USD ($)	Sep. 30, 2018USD ($)ATMbranch	Sep. 30, 2017USD ($)
Accounting Policies [Abstract]
Number of branches | branch			249
Number of ATMs | ATM			334
Reclassification from AOCI to retained earnings, tax effect	$ 7,600	$ 7,600
Future minimum lease commitments		230,000
Deferred gains on sale-leaseback transactions			$ 5,200
Basis Of Presentation [Line Items]
Adjustment from adoption of ASU			(685)	$ 0
ASU 2014-09
Basis Of Presentation [Line Items]
Adjustment from adoption of ASU		(685)
ASU 2016-01
Basis Of Presentation [Line Items]
Adjustment from adoption of ASU	$ 3,200	0	$ 3,200
ASU 2016-01 | Accumulated Other Comprehensive Income (Loss)
Basis Of Presentation [Line Items]
Adjustment from adoption of ASU		$ 117

Acquisitions (Details)

Acquisitions (Details) - USD ($) $ in Thousands	Sep. 25, 2017	Oct. 01, 2016	Nov. 30, 2017	Sep. 30, 2018	Sep. 30, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Common stock, shares issued (in shares)				143,093,317	143,093,317	142,677,449
Common stock				$ 143,093	$ 143,093	$ 142,678
Minimum
Business Acquisition [Line Items]
Period of additional annual payments					3 years
Maximum
Business Acquisition [Line Items]
Period of additional annual payments					5 years
World's Foremost Bank (WFB)
Business Acquisition [Line Items]
Brokered deposits	$ 1,100,000
Deposits portfolio, weighted average maturity, period	2 years 6 months 11 days
Weighted average rate of deposit, brokered	1.83%
Proceeds from fees	$ 75,000
Global One
Business Acquisition [Line Items]
Consideration transferred		$ 30,000
Common stock, shares issued (in shares)		821,000
Common stock		$ 26,600
Cash paid		$ 3,400
Earnout payment of stock and cash			$ 6,400
Increase in earnout liabilities				11,700
Earnout liability				$ 23,000	$ 23,000
Global One | Minimum
Business Acquisition [Line Items]
Potential additional payments based on earnings, period		3 years
Global One | Maximum
Business Acquisition [Line Items]
Potential additional payments based on earnings, period		5 years

Investment Securities Availab_3

Investment Securities Available for Sale (Summary Of Available For Sale Investment Securities) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 4,044,423	$ 4,038,239
Gross Unrealized Gains	402	6,107
Gross Unrealized Losses	(161,251)	(57,277)
Fair Value	3,883,574	3,987,069
U.S. Treasury securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	123,265	83,608
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(2,626)	(934)
Fair Value	120,639	82,674
U.S. Government agency securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	38,020	10,771
Gross Unrealized Gains	102	91
Gross Unrealized Losses	(258)	0
Fair Value	37,864	10,862
Mortgage-backed securities issued by U.S. Government agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	104,933	121,283
Gross Unrealized Gains	75	519
Gross Unrealized Losses	(4,125)	(1,362)
Fair Value	100,883	120,440
Mortgage-backed securities issued by U.S. Government sponsored enterprises
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,592,827	2,666,818
Gross Unrealized Gains	70	5,059
Gross Unrealized Losses	(103,532)	(31,354)
Fair Value	2,489,365	2,640,523
Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,168,378	1,135,259
Gross Unrealized Gains	0	144
Gross Unrealized Losses	(50,675)	(23,404)
Fair Value	1,117,703	1,111,999
State and municipal securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		180
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Fair Value		180
Corporate debt and other debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	17,000	20,320
Gross Unrealized Gains	155	294
Gross Unrealized Losses	(35)	(223)
Fair Value	$ 17,120	$ 20,391

Investment Securities Availab_4

Investment Securities Available for Sale (Narrative) (Details) $ in Thousands	Sep. 30, 2018USD ($)position	Jan. 01, 2018USD ($)	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)
Financing Receivable, Impaired [Line Items]
Investment securities in a loss position for less than twelve months | position	43
Investment securities in a loss position for twelve months or longer | position	100
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adjustment from adoption of ASU	$ (685)			$ 0
Collateral Pledged
Financing Receivable, Impaired [Line Items]
Pledged to secure deposits	1,290,000		$ 2,000,000
ASU 2016-01
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adjustment from adoption of ASU	$ 3,200	$ 3,200	$ 0

Investment Securities Availab_5

Investment Securities Available for Sale (Schedule Of Unrealized Loss On Investments) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Fair Value	$ 1,128,609	$ 1,995,846
Less than 12 Months, Unrealized Losses	29,532	20,560
12 Months or Longer, Fair Value	2,660,551	1,445,859
12 Months or Longer, Unrealized Losses	131,719	36,717
Total Fair Value, Fair Value	3,789,160	3,441,705
Total Fair Value, Unrealized Losses	161,251	57,277
U.S. Treasury securities
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Fair Value	38,352	34,243
Less than 12 Months, Unrealized Losses	739	443
12 Months or Longer, Fair Value	62,905	29,562
12 Months or Longer, Unrealized Losses	1,887	491
Total Fair Value, Fair Value	101,257	63,805
Total Fair Value, Unrealized Losses	2,626	934
U.S. Government agency securities
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Fair Value	29,727
Less than 12 Months, Unrealized Losses	258
12 Months or Longer, Fair Value	0
12 Months or Longer, Unrealized Losses	0
Total Fair Value, Fair Value	29,727
Total Fair Value, Unrealized Losses	258
Mortgage-backed securities issued by U.S. Government agencies
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Fair Value	15,655	36,810
Less than 12 Months, Unrealized Losses	364	357
12 Months or Longer, Fair Value	73,555	55,740
12 Months or Longer, Unrealized Losses	3,761	1,005
Total Fair Value, Fair Value	89,210	92,550
Total Fair Value, Unrealized Losses	4,125	1,362
Mortgage-backed securities issued by U.S. Government sponsored enterprises
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Fair Value	830,455	1,271,012
Less than 12 Months, Unrealized Losses	24,765	10,263
12 Months or Longer, Fair Value	1,618,843	929,223
12 Months or Longer, Unrealized Losses	78,767	21,091
Total Fair Value, Fair Value	2,449,298	2,200,235
Total Fair Value, Unrealized Losses	103,532	31,354
Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Fair Value	214,420	653,781
Less than 12 Months, Unrealized Losses	3,406	9,497
12 Months or Longer, Fair Value	903,283	426,237
12 Months or Longer, Unrealized Losses	47,269	13,907
Total Fair Value, Fair Value	1,117,703	1,080,018
Total Fair Value, Unrealized Losses	50,675	23,404
Corporate debt and other debt securities
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Fair Value	0	0
Less than 12 Months, Unrealized Losses	0	0
12 Months or Longer, Fair Value	1,965	5,097
12 Months or Longer, Unrealized Losses	35	223
Total Fair Value, Fair Value	1,965	5,097
Total Fair Value, Unrealized Losses	$ 35	$ 223

Investment Securities Availab_6

Investment Securities Available for Sale (Amortized Cost And Estimated Fair Value By Contractual Maturity Of Investment Securities Available For Sale) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Amortized Cost
Within One year, Amortized Cost	$ 21,299
1 to 5 Years, Amortized Cost	153,497
5 to 10 Years, Amortized Cost	655,126
More Than 10 years, Amortized Cost	3,214,501
Amortized Cost	4,044,423	$ 4,038,239
Fair Value
Within One Year, Fair Value	21,319
1 to 5 Years, Fair Value	150,087
5 to 10 Years, Fair Value	632,115
More Than 10 years, Fair Value	3,080,053
Total, Fair Value	3,883,574	3,987,069
U.S. Treasury securities
Amortized Cost
Within One year, Amortized Cost	19,382
1 to 5 Years, Amortized Cost	103,883
5 to 10 Years, Amortized Cost	0
More Than 10 years, Amortized Cost	0
Amortized Cost	123,265	83,608
Fair Value
Within One Year, Fair Value	19,382
1 to 5 Years, Fair Value	101,257
5 to 10 Years, Fair Value	0
More Than 10 years, Fair Value	0
Total, Fair Value	120,639	82,674
U.S. Government agency securities
Amortized Cost
Within One year, Amortized Cost	1,917
1 to 5 Years, Amortized Cost	6,118
5 to 10 Years, Amortized Cost	29,985
More Than 10 years, Amortized Cost	0
Amortized Cost	38,020	10,771
Fair Value
Within One Year, Fair Value	1,937
1 to 5 Years, Fair Value	6,200
5 to 10 Years, Fair Value	29,727
More Than 10 years, Fair Value	0
Total, Fair Value	37,864	10,862
Mortgage-backed securities issued by U.S. Government agencies
Amortized Cost
Within One year, Amortized Cost	0
1 to 5 Years, Amortized Cost	0
5 to 10 Years, Amortized Cost	25,659
More Than 10 years, Amortized Cost	79,274
Amortized Cost	104,933	121,283
Fair Value
Within One Year, Fair Value	0
1 to 5 Years, Fair Value	0
5 to 10 Years, Fair Value	25,154
More Than 10 years, Fair Value	75,729
Total, Fair Value	100,883	120,440
Mortgage-backed securities issued by U.S. Government sponsored enterprises
Amortized Cost
Within One year, Amortized Cost	0
1 to 5 Years, Amortized Cost	43,496
5 to 10 Years, Amortized Cost	556,115
More Than 10 years, Amortized Cost	1,993,216
Amortized Cost	2,592,827	2,666,818
Fair Value
Within One Year, Fair Value	0
1 to 5 Years, Fair Value	42,630
5 to 10 Years, Fair Value	534,881
More Than 10 years, Fair Value	1,911,854
Total, Fair Value	2,489,365	2,640,523
Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises
Amortized Cost
Within One year, Amortized Cost	0
1 to 5 Years, Amortized Cost	0
5 to 10 Years, Amortized Cost	28,367
More Than 10 years, Amortized Cost	1,140,011
Amortized Cost	1,168,378
Fair Value
Within One Year, Fair Value	0
1 to 5 Years, Fair Value	0
5 to 10 Years, Fair Value	27,198
More Than 10 years, Fair Value	1,090,505
Total, Fair Value	1,117,703
Corporate debt and other debt securities
Amortized Cost
Within One year, Amortized Cost	0
1 to 5 Years, Amortized Cost	0
5 to 10 Years, Amortized Cost	15,000
More Than 10 years, Amortized Cost	2,000
Amortized Cost	17,000	20,320
Fair Value
Within One Year, Fair Value	0
1 to 5 Years, Fair Value	0
5 to 10 Years, Fair Value	15,155
More Than 10 years, Fair Value	1,965
Total, Fair Value	$ 17,120	$ 20,391

Investment Securities Availab_7

Investment Securities Available for Sale (Summary Of Sales Transactions In The Investment Securities Available For Sale Portfolio) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Investments [Abstract]
Proceeds from sales of investment securities available for sale	$ 0	$ 473,912	$ 35,066	$ 812,293
Gross realized gains on sales	0	0	0	7,942
Gross realized losses on sales	0	(7,956)	(1,296)	(8,231)
Investment securities losses, net	$ 0	$ (7,956)	$ (1,296)	$ (289)

Loans and Allowance for Loan _3

Loans and Allowance for Loan Losses (Schedule Of Current, Accruing Past Due And Nonaccrual Loans) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	$ 25,577,116	$ 24,787,464
Non-accrual	108,425	115,561
Total loans	25,600,897	24,812,795	$ 24,511,638
Deferred fees and costs, net	(23,800)	(25,300)	$ (24,300)
Total commercial and industrial
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Non-accrual	74,718	76,784
Total loans	12,503,294	12,023,650
Total commercial and industrial | Commercial, financial and agricultural
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Non-accrual	69,010	70,130
Total loans	7,281,466	7,179,487
Total commercial and industrial | Owner-occupied
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Non-accrual	5,708	6,654
Total loans	5,221,828	4,844,163
Total commercial real estate
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Non-accrual	10,123	12,450
Total loans	6,712,406	6,935,288
Total commercial real estate | Investment properties
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Non-accrual	2,155	3,804
Total loans	5,665,690	5,670,065
Total commercial real estate | 1-4 family properties
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Non-accrual	3,139	2,849
Total loans	707,196	781,619
Total commercial real estate | Land and development
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Non-accrual	4,829	5,797
Total loans	339,520	483,604
Total consumer
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Non-accrual	23,584	26,327
Total loans	6,385,197	5,853,857
Total consumer | Home equity lines
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Non-accrual	14,498	17,455
Total loans	1,465,419	1,514,227
Total consumer | Consumer mortgages
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Non-accrual	5,313	7,203
Total loans	2,843,244	2,633,503
Total consumer | Credit cards
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Non-accrual	0	0
Total loans	245,149	232,676
Total consumer | Other consumer loans
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Non-accrual	3,773	1,669
Total loans	1,831,385	1,473,451
Current
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	25,414,148	24,645,203
Current | Total commercial and industrial
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	12,391,639	11,927,277
Current | Total commercial and industrial | Commercial, financial and agricultural
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	7,185,447	7,097,127
Current | Total commercial and industrial | Owner-occupied
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	5,206,192	4,830,150
Current | Total commercial real estate
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	6,696,720	6,914,819
Current | Total commercial real estate | Investment properties
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	5,661,605	5,663,665
Current | Total commercial real estate | 1-4 family properties
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	701,406	775,023
Current | Total commercial real estate | Land and development
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	333,709	476,131
Current | Total consumer
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	6,325,789	5,803,107
Current | Total consumer | Home equity lines
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	1,442,451	1,490,808
Current | Total consumer | Consumer mortgages
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	2,832,971	2,622,061
Current | Total consumer | Credit cards
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	241,334	229,015
Current | Total consumer | Other consumer loans
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	1,809,033	1,461,223
Accruing 30-89 Days Past Due
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	73,468	47,617
Accruing 30-89 Days Past Due | Total commercial and industrial
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	34,729	18,094
Accruing 30-89 Days Past Due | Total commercial and industrial | Commercial, financial and agricultural
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	25,850	11,214
Accruing 30-89 Days Past Due | Total commercial and industrial | Owner-occupied
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	8,879	6,880
Accruing 30-89 Days Past Due | Total commercial real estate
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	5,346	7,660
Accruing 30-89 Days Past Due | Total commercial real estate | Investment properties
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	1,930	2,506
Accruing 30-89 Days Past Due | Total commercial real estate | 1-4 family properties
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	2,651	3,545
Accruing 30-89 Days Past Due | Total commercial real estate | Land and development
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	765	1,609
Accruing 30-89 Days Past Due | Total consumer
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	33,393	21,863
Accruing 30-89 Days Past Due | Total consumer | Home equity lines
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	7,819	5,629
Accruing 30-89 Days Past Due | Total consumer | Consumer mortgages
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	4,960	3,971
Accruing 30-89 Days Past Due | Total consumer | Credit cards
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	2,170	1,930
Accruing 30-89 Days Past Due | Total consumer | Other consumer loans
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	18,444	10,333
Accruing 90 Days or Greater Past Due
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	4,856	4,414
Accruing 90 Days or Greater Past Due | Total commercial and industrial
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	2,208	1,495
Accruing 90 Days or Greater Past Due | Total commercial and industrial | Commercial, financial and agricultural
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	1,159	1,016
Accruing 90 Days or Greater Past Due | Total commercial and industrial | Owner-occupied
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	1,049	479
Accruing 90 Days or Greater Past Due | Total commercial real estate
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	217	359
Accruing 90 Days or Greater Past Due | Total commercial real estate | Investment properties
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	0	90
Accruing 90 Days or Greater Past Due | Total commercial real estate | 1-4 family properties
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	0	202
Accruing 90 Days or Greater Past Due | Total commercial real estate | Land and development
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	217	67
Accruing 90 Days or Greater Past Due | Total consumer
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	2,431	2,560
Accruing 90 Days or Greater Past Due | Total consumer | Home equity lines
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	651	335
Accruing 90 Days or Greater Past Due | Total consumer | Consumer mortgages
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	0	268
Accruing 90 Days or Greater Past Due | Total consumer | Credit cards
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	1,645	1,731
Accruing 90 Days or Greater Past Due | Total consumer | Other consumer loans
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	135	226
Total Accruing Past Due
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	78,324	52,031
Total Accruing Past Due | Total commercial and industrial
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	36,937	19,589
Total Accruing Past Due | Total commercial and industrial | Commercial, financial and agricultural
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	27,009	12,230
Total Accruing Past Due | Total commercial and industrial | Owner-occupied
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	9,928	7,359
Total Accruing Past Due | Total commercial real estate
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	5,563	8,019
Total Accruing Past Due | Total commercial real estate | Investment properties
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	1,930	2,596
Total Accruing Past Due | Total commercial real estate | 1-4 family properties
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	2,651	3,747
Total Accruing Past Due | Total commercial real estate | Land and development
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	982	1,676
Total Accruing Past Due | Total consumer
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	35,824	24,423
Total Accruing Past Due | Total consumer | Home equity lines
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	8,470	5,964
Total Accruing Past Due | Total consumer | Consumer mortgages
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	4,960	4,239
Total Accruing Past Due | Total consumer | Credit cards
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	3,815	3,661
Total Accruing Past Due | Total consumer | Other consumer loans
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Loans and leases receivables	$ 18,579	$ 10,559

Loans and Allowance for Loan _4

Loans and Allowance for Loan Losses (Narrative) (Details)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018USD ($)contract	Sep. 30, 2017USD ($)contract	Sep. 30, 2018USD ($)contract	Sep. 30, 2017USD ($)contract	Dec. 31, 2017USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans pledged as collateral	$ 8,110,000,000		$ 8,110,000,000		$ 7,930,000,000
Average recorded investment in impaired loans	174,925,000	$ 218,700,000	189,096,000	$ 228,900,000	223,009,000
Interest income recognized	1,308,000	0	4,089,000	0	6,961,000
Interest income recognized for accruing TDRs	1,700,000	1,700,000		5,200,000
Non-accrual status	54,900,000		54,900,000		49,000,000
Recorded investment	11,795,000	14,907,000	37,160,000	30,285,000
Provision for loan losses	14,982,000	$ 39,686,000	39,548,000	$ 58,620,000
Accruing TDRs With Modifications And Renewals Completed
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision for loan losses			$ 6,900,000		8,700,000
Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retail loan substandard period (in days)			90 days
Loss And Charged Off
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retail loans downgraded to loss (in days)			120 days
Accruing TDRs With Modifications And Renewals Completed
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing troubled debt restructuring	$ 114,700,000		$ 114,700,000		$ 151,300,000
Accruing TDRs With Modifications And Renewals Completed | Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial-type impaired loans			$ 1,000,000
Troubled Debt Restructuring That Subsequently Defaults
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of contracts | contract	0	1	8	4
Recorded investment	$ 0	$ 206,000	$ 10,500,000	$ 498,000

Loans and Allowance for Loan _5

Loans and Allowance for Loan Losses (Loan Portfolio Credit Exposure) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 25,600,897	$ 24,812,795	$ 24,511,638
Accrual substandard loans	204,100	190,600
Deferred fees and costs, net	$ (23,800)	(25,300)	$ (24,300)
Maximum
Financing Receivable, Recorded Investment [Line Items]
Allowance for loan losses, percent of loan amount	50.00%
Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 24,992,755	24,222,726
Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	295,597	283,865
Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	304,655	297,640
Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans	5,339	5,358
Loss
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,551	3,206
Total commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total loans	12,503,294	12,023,650
Total commercial and industrial | Commercial, financial and agricultural
Financing Receivable, Recorded Investment [Line Items]
Total loans	7,281,466	7,179,487
Total commercial and industrial | Owner-occupied
Financing Receivable, Recorded Investment [Line Items]
Total loans	5,221,828	4,844,163
Total commercial and industrial | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	12,064,327	11,643,383
Total commercial and industrial | Pass | Commercial, financial and agricultural
Financing Receivable, Recorded Investment [Line Items]
Total loans	6,986,930	6,929,506
Total commercial and industrial | Pass | Owner-occupied
Financing Receivable, Recorded Investment [Line Items]
Total loans	5,077,397	4,713,877
Total commercial and industrial | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	215,326	166,052
Total commercial and industrial | Special Mention | Commercial, financial and agricultural
Financing Receivable, Recorded Investment [Line Items]
Total loans	135,359	115,912
Total commercial and industrial | Special Mention | Owner-occupied
Financing Receivable, Recorded Investment [Line Items]
Total loans	79,967	50,140
Total commercial and industrial | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	221,960	212,891
Total commercial and industrial | Substandard | Commercial, financial and agricultural
Financing Receivable, Recorded Investment [Line Items]
Total loans	157,922	132,818
Total commercial and industrial | Substandard | Owner-occupied
Financing Receivable, Recorded Investment [Line Items]
Total loans	64,038	80,073
Total commercial and industrial | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,677	1,324
Total commercial and industrial | Doubtful | Commercial, financial and agricultural
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,251	1,251
Total commercial and industrial | Doubtful | Owner-occupied
Financing Receivable, Recorded Investment [Line Items]
Total loans	426	73
Total commercial and industrial | Loss
Financing Receivable, Recorded Investment [Line Items]
Total loans	4	0
Total commercial and industrial | Loss | Commercial, financial and agricultural
Financing Receivable, Recorded Investment [Line Items]
Total loans	4	0
Total commercial and industrial | Loss | Owner-occupied
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Total commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	6,712,406	6,935,288
Total commercial real estate | Investment properties
Financing Receivable, Recorded Investment [Line Items]
Total loans	5,665,690	5,670,065
Total commercial real estate | 1-4 family properties
Financing Receivable, Recorded Investment [Line Items]
Total loans	707,196	781,619
Total commercial real estate | Land and development
Financing Receivable, Recorded Investment [Line Items]
Total loans	339,520	483,604
Total commercial real estate | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	6,573,860	6,763,850
Total commercial real estate | Pass | Investment properties
Financing Receivable, Recorded Investment [Line Items]
Total loans	5,587,389	5,586,792
Total commercial real estate | Pass | 1-4 family properties
Financing Receivable, Recorded Investment [Line Items]
Total loans	687,775	745,299
Total commercial real estate | Pass | Land and development
Financing Receivable, Recorded Investment [Line Items]
Total loans	298,696	431,759
Total commercial real estate | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	80,271	117,813
Total commercial real estate | Special Mention | Investment properties
Financing Receivable, Recorded Investment [Line Items]
Total loans	47,667	64,628
Total commercial real estate | Special Mention | 1-4 family properties
Financing Receivable, Recorded Investment [Line Items]
Total loans	7,943	19,419
Total commercial real estate | Special Mention | Land and development
Financing Receivable, Recorded Investment [Line Items]
Total loans	24,661	33,766
Total commercial real estate | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	54,801	50,496
Total commercial real estate | Substandard | Investment properties
Financing Receivable, Recorded Investment [Line Items]
Total loans	30,634	18,645
Total commercial real estate | Substandard | 1-4 family properties
Financing Receivable, Recorded Investment [Line Items]
Total loans	11,478	16,901
Total commercial real estate | Substandard | Land and development
Financing Receivable, Recorded Investment [Line Items]
Total loans	12,689	14,950
Total commercial real estate | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,129	3,129
Total commercial real estate | Doubtful | Investment properties
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Total commercial real estate | Doubtful | 1-4 family properties
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Total commercial real estate | Doubtful | Land and development
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,129	3,129
Total commercial real estate | Loss
Financing Receivable, Recorded Investment [Line Items]
Total loans	345	0
Total commercial real estate | Loss | Investment properties
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Total commercial real estate | Loss | 1-4 family properties
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Total commercial real estate | Loss | Land and development
Financing Receivable, Recorded Investment [Line Items]
Total loans	345	0
Total consumer
Financing Receivable, Recorded Investment [Line Items]
Total loans	6,385,197	5,853,857
Total consumer | Home equity lines
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,465,419	1,514,227
Total consumer | Consumer mortgages
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,843,244	2,633,503
Total consumer | Credit cards
Financing Receivable, Recorded Investment [Line Items]
Total loans	245,149	232,676
Total consumer | Other consumer loans
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,831,385	1,473,451
Total consumer | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	6,354,568	5,815,493
Total consumer | Pass | Home equity lines
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,446,606	1,491,105
Total consumer | Pass | Consumer mortgages
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,836,972	2,622,499
Total consumer | Pass | Credit cards
Financing Receivable, Recorded Investment [Line Items]
Total loans	243,503	230,945
Total consumer | Pass | Other consumer loans
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,827,487	1,470,944
Total consumer | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Total consumer | Special Mention | Home equity lines
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Total consumer | Special Mention | Consumer mortgages
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Total consumer | Special Mention | Credit cards
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Total consumer | Special Mention | Other consumer loans
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Total consumer | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	27,894	34,253
Total consumer | Substandard | Home equity lines
Financing Receivable, Recorded Investment [Line Items]
Total loans	17,513	21,079
Total consumer | Substandard | Consumer mortgages
Financing Receivable, Recorded Investment [Line Items]
Total loans	6,171	10,607
Total consumer | Substandard | Credit cards
Financing Receivable, Recorded Investment [Line Items]
Total loans	570	399
Total consumer | Substandard | Other consumer loans
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,640	2,168
Total consumer | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans	533	905
Total consumer | Doubtful | Home equity lines
Financing Receivable, Recorded Investment [Line Items]
Total loans	175	285
Total consumer | Doubtful | Consumer mortgages
Financing Receivable, Recorded Investment [Line Items]
Total loans	101	291
Total consumer | Doubtful | Credit cards
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Total consumer | Doubtful | Other consumer loans
Financing Receivable, Recorded Investment [Line Items]
Total loans	257	329
Total consumer | Loss
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,202	3,206
Total consumer | Loss | Home equity lines
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,125	1,758
Total consumer | Loss | Consumer mortgages
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	106
Total consumer | Loss | Credit cards
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,076	1,332
Total consumer | Loss | Other consumer loans
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 1	$ 10

Loans and Allowance for Loan _6

Loans and Allowance for Loan Losses (Schedule Of Allowances For Loan Losses And Recorded Investment In Loans) (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Allowance for loan losses:
Beginning balance, allowance	$ 251,725,000	$ 248,095,000	$ 249,268,000	$ 251,758,000	$ 251,758,000
Charge-offs	(18,596,000)	(44,351,000)	(54,723,000)	(76,749,000)
Recoveries	3,339,000	6,253,000	17,357,000	16,054,000
Provision for loan losses	14,982,000	39,686,000	39,548,000	58,620,000
Ending balance, allowance	251,450,000	249,683,000	251,450,000	249,683,000	249,268,000
Ending balance: individually evaluated for impairment, allowance	13,395,000	12,251,000	13,395,000	12,251,000
Ending balance: collectively evaluated for impairment, allowance	238,055,000	237,432,000	238,055,000	237,432,000
Total loans	25,600,897,000	24,511,638,000	25,600,897,000	24,511,638,000	24,812,795,000
Ending balance: individually evaluated for impairment, loans	169,622,000	204,475,000	169,622,000	204,475,000
Ending balance: collectively evaluated for impairment, loans	25,431,275,000	24,307,163,000	25,431,275,000	24,307,163,000
Purchased credit-impaired loans	0	0	0	0
Allowance for purchased credit-impaired loans	0	0		0
Deferred fees and costs, net	(23,800,000)	(24,300,000)	(23,800,000)	(24,300,000)	(25,300,000)
Commercial & Industrial
Allowance for loan losses:
Beginning balance, allowance	130,335,000	123,437,000	126,803,000	125,778,000	125,778,000
Charge-offs	(13,526,000)	(21,855,000)	(37,312,000)	(41,390,000)
Recoveries	1,091,000	1,899,000	5,086,000	5,181,000
Provision for loan losses	11,417,000	23,022,000	34,740,000	36,934,000
Ending balance, allowance	129,317,000	126,503,000	129,317,000	126,503,000	126,803,000
Ending balance: individually evaluated for impairment, allowance	9,108,000	7,360,000	9,108,000	7,360,000
Ending balance: collectively evaluated for impairment, allowance	120,209,000	119,143,000	120,209,000	119,143,000
Total loans	12,503,294,000	11,727,142,000	12,503,294,000	11,727,142,000
Ending balance: individually evaluated for impairment, loans	102,671,000	109,434,000	102,671,000	109,434,000
Ending balance: collectively evaluated for impairment, loans	12,400,623,000	11,617,708,000	12,400,623,000	11,617,708,000
Commercial Real Estate
Allowance for loan losses:
Beginning balance, allowance	75,205,000	77,527,000	74,998,000	81,816,000	81,816,000
Charge-offs	(1,077,000)	(8,129,000)	(3,523,000)	(11,336,000)
Recoveries	591,000	2,543,000	7,555,000	6,191,000
Provision for loan losses	(1,447,000)	6,019,000	(5,758,000)	1,289,000
Ending balance, allowance	73,272,000	77,960,000	73,272,000	77,960,000	74,998,000
Ending balance: individually evaluated for impairment, allowance	3,317,000	4,108,000	3,317,000	4,108,000
Ending balance: collectively evaluated for impairment, allowance	69,955,000	73,852,000	69,955,000	73,852,000
Total loans	6,712,406,000	7,226,924,000	6,712,406,000	7,226,924,000
Ending balance: individually evaluated for impairment, loans	37,988,000	64,909,000	37,988,000	64,909,000
Ending balance: collectively evaluated for impairment, loans	6,674,418,000	7,162,015,000	6,674,418,000	7,162,015,000
Consumer
Allowance for loan losses:
Beginning balance, allowance	46,185,000	47,131,000	47,467,000	44,164,000	44,164,000
Charge-offs	(3,993,000)	(14,367,000)	(13,888,000)	(24,023,000)
Recoveries	1,657,000	1,811,000	4,716,000	4,682,000
Provision for loan losses	5,012,000	10,645,000	10,566,000	20,397,000
Ending balance, allowance	48,861,000	45,220,000	48,861,000	45,220,000	$ 47,467,000
Ending balance: individually evaluated for impairment, allowance	970,000	783,000	970,000	783,000
Ending balance: collectively evaluated for impairment, allowance	47,891,000	44,437,000	47,891,000	44,437,000
Total loans	6,385,197,000	5,557,572,000	6,385,197,000	5,557,572,000
Ending balance: individually evaluated for impairment, loans	28,963,000	30,132,000	28,963,000	30,132,000
Ending balance: collectively evaluated for impairment, loans	$ 6,356,234,000	$ 5,527,440,000	$ 6,356,234,000	$ 5,527,440,000

Loans and Allowance for Loan _7

Loans and Allowance for Loan Losses (Schedule Of Impaired Loans) (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	$ 21,182,000		$ 21,182,000		$ 11,022,000
Recorded Investment, With allowance recorded	148,440,000		148,440,000		189,264,000
Recorded Investment	169,622,000		169,622,000		200,286,000
Unpaid Principal Balance, With no related allowance recorded	28,048,000		28,048,000		14,259,000
Unpaid Principal Balance, With allowance recorded	151,827,000		151,827,000		189,498,000
Unpaid Principal Balance	179,875,000		179,875,000		203,757,000
Related Allowance	13,395,000		13,395,000		14,908,000
Average Recorded Investment, With no related allowance recorded	21,248,000		16,350,000		32,314,000
Average Recorded Investment, With allowance recorded	153,677,000		172,746,000		190,695,000
Average Recorded Investment	174,925,000	$ 218,700,000	189,096,000	$ 228,900,000	223,009,000
Interest Income Recognized, With no related allowance recorded	0		0		0
Interest Income Recognized, With allowance recorded	1,308,000		4,089,000		6,961,000
Interest Income Recognized	1,308,000	$ 0	4,089,000	$ 0	6,961,000
Total commercial and industrial
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	20,884,000		20,884,000		8,220,000
Recorded Investment, With allowance recorded	81,787,000		81,787,000		103,114,000
Recorded Investment	102,671,000		102,671,000		111,334,000
Unpaid Principal Balance, With no related allowance recorded	26,878,000		26,878,000		9,576,000
Unpaid Principal Balance, With allowance recorded	83,419,000		83,419,000		103,292,000
Unpaid Principal Balance	110,297,000		110,297,000		112,868,000
Related Allowance	9,108,000		9,108,000		9,515,000
Average Recorded Investment, With no related allowance recorded	21,118,000		14,458,000		28,351,000
Average Recorded Investment, With allowance recorded	84,502,000		95,259,000		90,966,000
Average Recorded Investment	105,620,000		109,717,000		119,317,000
Interest Income Recognized, With no related allowance recorded	0		0		0
Interest Income Recognized, With allowance recorded	578,000		1,736,000		2,992,000
Interest Income Recognized	578,000		1,736,000		2,992,000
Total commercial and industrial | Commercial, financial and agricultural
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	20,884,000		20,884,000		8,220,000
Recorded Investment, With allowance recorded	35,181,000		35,181,000		65,715,000
Recorded Investment	56,065,000		56,065,000		73,935,000
Unpaid Principal Balance, With no related allowance recorded	26,878,000		26,878,000		9,576,000
Unpaid Principal Balance, With allowance recorded	36,127,000		36,127,000		65,851,000
Unpaid Principal Balance	63,005,000		63,005,000		75,427,000
Related Allowance	6,024,000		6,024,000		7,406,000
Average Recorded Investment, With no related allowance recorded	21,118,000		14,458,000		21,686,000
Average Recorded Investment, With allowance recorded	40,136,000		55,088,000		50,468,000
Average Recorded Investment	61,254,000		69,546,000		72,154,000
Interest Income Recognized, With no related allowance recorded	0		0		0
Interest Income Recognized, With allowance recorded	143,000		571,000		1,610,000
Interest Income Recognized	143,000		571,000		1,610,000
Total commercial and industrial | Owner-occupied
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	0		0		0
Recorded Investment, With allowance recorded	46,606,000		46,606,000		37,399,000
Recorded Investment	46,606,000		46,606,000		37,399,000
Unpaid Principal Balance, With no related allowance recorded	0		0		0
Unpaid Principal Balance, With allowance recorded	47,292,000		47,292,000		37,441,000
Unpaid Principal Balance	47,292,000		47,292,000		37,441,000
Related Allowance	3,084,000		3,084,000		2,109,000
Average Recorded Investment, With no related allowance recorded	0		0		6,665,000
Average Recorded Investment, With allowance recorded	44,366,000		40,171,000		40,498,000
Average Recorded Investment	44,366,000		40,171,000		47,163,000
Interest Income Recognized, With no related allowance recorded	0		0		0
Interest Income Recognized, With allowance recorded	435,000		1,165,000		1,382,000
Interest Income Recognized	435,000		1,165,000		1,382,000
Total commercial real estate
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	265,000		265,000		56,000
Recorded Investment, With allowance recorded	37,723,000		37,723,000		56,840,000
Recorded Investment	37,988,000		37,988,000		56,896,000
Unpaid Principal Balance, With no related allowance recorded	1,110,000		1,110,000		1,740,000
Unpaid Principal Balance, With allowance recorded	39,464,000		39,464,000		56,896,000
Unpaid Principal Balance	40,574,000		40,574,000		58,636,000
Related Allowance	3,317,000		3,317,000		4,240,000
Average Recorded Investment, With no related allowance recorded	88,000		42,000		2,262,000
Average Recorded Investment, With allowance recorded	40,534,000		49,078,000		68,344,000
Average Recorded Investment	40,622,000		49,120,000		70,606,000
Interest Income Recognized, With no related allowance recorded	0		0		0
Interest Income Recognized, With allowance recorded	416,000		1,427,000		2,473,000
Interest Income Recognized	416,000		1,427,000		2,473,000
Total commercial real estate | Investment properties
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	0		0		0
Recorded Investment, With allowance recorded	13,846,000		13,846,000		23,364,000
Recorded Investment	13,846,000		13,846,000		23,364,000
Unpaid Principal Balance, With no related allowance recorded	0		0		0
Unpaid Principal Balance, With allowance recorded	13,846,000		13,846,000		23,364,000
Unpaid Principal Balance	13,846,000		13,846,000		23,364,000
Related Allowance	1,566,000		1,566,000		1,100,000
Average Recorded Investment, With no related allowance recorded	0		0		123,000
Average Recorded Investment, With allowance recorded	14,103,000		20,437,000		28,749,000
Average Recorded Investment	14,103,000		20,437,000		28,872,000
Interest Income Recognized, With no related allowance recorded	0		0		0
Interest Income Recognized, With allowance recorded	179,000		597,000		1,144,000
Interest Income Recognized	179,000		597,000		1,144,000
Total commercial real estate | 1-4 family properties
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	0		0		0
Recorded Investment, With allowance recorded	8,307,000		8,307,000		15,056,000
Recorded Investment	8,307,000		8,307,000		15,056,000
Unpaid Principal Balance, With no related allowance recorded	0		0		0
Unpaid Principal Balance, With allowance recorded	8,307,000		8,307,000		15,056,000
Unpaid Principal Balance	8,307,000		8,307,000		15,056,000
Related Allowance	191,000		191,000		504,000
Average Recorded Investment, With no related allowance recorded	0		0		323,000
Average Recorded Investment, With allowance recorded	9,697,000		10,876,000		16,257,000
Average Recorded Investment	9,697,000		10,876,000		16,580,000
Interest Income Recognized, With no related allowance recorded	0		0		0
Interest Income Recognized, With allowance recorded	176,000		619,000		925,000
Interest Income Recognized	176,000		619,000		925,000
Total commercial real estate | Land and development
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	265,000		265,000		56,000
Recorded Investment, With allowance recorded	15,570,000		15,570,000		18,420,000
Recorded Investment	15,835,000		15,835,000		18,476,000
Unpaid Principal Balance, With no related allowance recorded	1,110,000		1,110,000		1,740,000
Unpaid Principal Balance, With allowance recorded	17,311,000		17,311,000		18,476,000
Unpaid Principal Balance	18,421,000		18,421,000		20,216,000
Related Allowance	1,560,000		1,560,000		2,636,000
Average Recorded Investment, With no related allowance recorded	88,000		42,000		1,816,000
Average Recorded Investment, With allowance recorded	16,734,000		17,765,000		23,338,000
Average Recorded Investment	16,822,000		17,807,000		25,154,000
Interest Income Recognized, With no related allowance recorded	0		0		0
Interest Income Recognized, With allowance recorded	61,000		211,000		404,000
Interest Income Recognized	61,000		211,000		404,000
Total consumer
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	33,000		33,000		2,746,000
Recorded Investment, With allowance recorded	28,930,000		28,930,000		29,310,000
Recorded Investment	28,963,000		28,963,000		32,056,000
Unpaid Principal Balance, With no related allowance recorded	60,000		60,000		2,943,000
Unpaid Principal Balance, With allowance recorded	28,944,000		28,944,000		29,310,000
Unpaid Principal Balance	29,004,000		29,004,000		32,253,000
Related Allowance	970,000		970,000		1,153,000
Average Recorded Investment, With no related allowance recorded	42,000		1,850,000		1,701,000
Average Recorded Investment, With allowance recorded	28,641,000		28,409,000		31,385,000
Average Recorded Investment	28,683,000		30,259,000		33,086,000
Interest Income Recognized, With no related allowance recorded	0		0		0
Interest Income Recognized, With allowance recorded	314,000		926,000		1,496,000
Interest Income Recognized	314,000		926,000		1,496,000
Total consumer | Home equity lines
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	0		0		2,746,000
Recorded Investment, With allowance recorded	3,209,000		3,209,000		5,096,000
Recorded Investment	3,209,000		3,209,000		7,842,000
Unpaid Principal Balance, With no related allowance recorded	0		0		2,943,000
Unpaid Principal Balance, With allowance recorded	3,223,000		3,223,000		5,096,000
Unpaid Principal Balance	3,223,000		3,223,000		8,039,000
Related Allowance	236,000		236,000		114,000
Average Recorded Investment, With no related allowance recorded	0		949,000		1,205,000
Average Recorded Investment, With allowance recorded	3,433,000		3,693,000		7,476,000
Average Recorded Investment	3,433,000		4,642,000		8,681,000
Interest Income Recognized, With no related allowance recorded	0		0		0
Interest Income Recognized, With allowance recorded	20,000		96,000		334,000
Interest Income Recognized	20,000		96,000		334,000
Total consumer | Consumer mortgages
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	33,000		33,000		0
Recorded Investment, With allowance recorded	20,201,000		20,201,000		18,668,000
Recorded Investment	20,234,000		20,234,000		18,668,000
Unpaid Principal Balance, With no related allowance recorded	60,000		60,000		0
Unpaid Principal Balance, With allowance recorded	20,201,000		20,201,000		18,668,000
Unpaid Principal Balance	20,261,000		20,261,000		18,668,000
Related Allowance	575,000		575,000		569,000
Average Recorded Investment, With no related allowance recorded	42,000		901,000		496,000
Average Recorded Investment, With allowance recorded	19,924,000		19,496,000		19,144,000
Average Recorded Investment	19,966,000		20,397,000		19,640,000
Interest Income Recognized, With no related allowance recorded	0		0		0
Interest Income Recognized, With allowance recorded	225,000		618,000		896,000
Interest Income Recognized	225,000		618,000		896,000
Total consumer | Credit cards
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	0		0		0
Recorded Investment, With allowance recorded	0		0		0
Recorded Investment	0		0		0
Unpaid Principal Balance, With no related allowance recorded	0		0		0
Unpaid Principal Balance, With allowance recorded	0		0		0
Unpaid Principal Balance	0		0		0
Related Allowance	0		0		0
Average Recorded Investment, With no related allowance recorded	0		0		0
Average Recorded Investment, With allowance recorded	0		0		0
Average Recorded Investment	0		0		0
Interest Income Recognized, With no related allowance recorded	0		0		0
Interest Income Recognized, With allowance recorded	0		0		0
Interest Income Recognized	0		0		0
Total consumer | Other consumer loans
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	0		0		0
Recorded Investment, With allowance recorded	5,520,000		5,520,000		5,546,000
Recorded Investment	5,520,000		5,520,000		5,546,000
Unpaid Principal Balance, With no related allowance recorded	0		0		0
Unpaid Principal Balance, With allowance recorded	5,520,000		5,520,000		5,546,000
Unpaid Principal Balance	5,520,000		5,520,000		5,546,000
Related Allowance	159,000		159,000		470,000
Average Recorded Investment, With no related allowance recorded	0		0		0
Average Recorded Investment, With allowance recorded	5,284,000		5,220,000		4,765,000
Average Recorded Investment	5,284,000		5,220,000		4,765,000
Interest Income Recognized, With no related allowance recorded	0		0		0
Interest Income Recognized, With allowance recorded	69,000		212,000		266,000
Interest Income Recognized	$ 69,000		$ 212,000		$ 266,000

Loans and Allowance for Loan _8

Loans and Allowance for Loan Losses (Troubled Debt Restructurings) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2018USD ($)Contract	Sep. 30, 2017USD ($)Contract	Sep. 30, 2018USD ($)Contract	Sep. 30, 2017USD ($)Contract
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	64	57	145	112
Recorded Investment	$ 11,795,000	$ 14,907,000	$ 37,160,000	$ 30,285,000
Net charge-offs	$ 88,000	$ 0	$ 88,000	$ 0
Total commercial and industrial
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	10	25	30	54
Recorded Investment	$ 6,131,000	$ 10,527,000	$ 13,179,000	$ 22,588,000
Total commercial and industrial | Commercial, financial and agricultural
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	7	22	21	50
Recorded Investment	$ 565,000	$ 8,809,000	$ 2,130,000	$ 20,848,000
Total commercial and industrial | Owner-occupied
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	3	3	9	4
Recorded Investment	$ 5,566,000	$ 1,718,000	$ 11,049,000	$ 1,740,000
Total commercial real estate
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	7	8	20	25
Recorded Investment	$ 1,324,000	$ 1,881,000	$ 12,791,000	$ 4,619,000
Total commercial real estate | Investment properties
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	1	0	4	0
Recorded Investment	$ 42,000	$ 0	$ 8,268,000	$ 0
Total commercial real estate | 1-4 family properties
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	5	5	12	21
Recorded Investment	$ 1,211,000	$ 964,000	$ 2,667,000	$ 3,567,000
Total commercial real estate | Land and development
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	1	3	4	4
Recorded Investment	$ 71,000	$ 917,000	$ 1,856,000	$ 1,052,000
Total consumer
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	47	24	95	33
Recorded Investment	$ 4,340,000	$ 2,499,000	$ 11,190,000	$ 3,078,000
Total consumer | Home equity lines
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	1	0	4	0
Recorded Investment	$ 191,000	$ 0	$ 511,000	$ 0
Total consumer | Consumer mortgages
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	2	7	16	8
Recorded Investment	$ 670,000	$ 1,429,000	$ 5,452,000	$ 1,438,000
Total consumer | Credit cards
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0	0	0
Recorded Investment	$ 0	$ 0	$ 0	$ 0
Total consumer | Other consumer loans
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	44	17	75	25
Recorded Investment	$ 3,479,000	$ 1,070,000	$ 5,227,000	$ 1,640,000
Principal Forgiveness
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Principal Forgiveness | Total commercial and industrial
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Principal Forgiveness | Total commercial and industrial | Commercial, financial and agricultural
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Principal Forgiveness | Total commercial and industrial | Owner-occupied
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Principal Forgiveness | Total commercial real estate
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Principal Forgiveness | Total commercial real estate | Investment properties
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Principal Forgiveness | Total commercial real estate | 1-4 family properties
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Principal Forgiveness | Total commercial real estate | Land and development
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Principal Forgiveness | Total consumer
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Principal Forgiveness | Total consumer | Home equity lines
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Principal Forgiveness | Total consumer | Consumer mortgages
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Principal Forgiveness | Total consumer | Credit cards
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Principal Forgiveness | Total consumer | Other consumer loans
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Below Market Interest Rate
Financing Receivable, Modifications [Line Items]
Recorded Investment	2,579,000	4,065,000	20,145,000	11,915,000
Below Market Interest Rate | Total commercial and industrial
Financing Receivable, Modifications [Line Items]
Recorded Investment	727,000	2,978,000	5,526,000	8,738,000
Below Market Interest Rate | Total commercial and industrial | Commercial, financial and agricultural
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	2,943,000	0	8,703,000
Below Market Interest Rate | Total commercial and industrial | Owner-occupied
Financing Receivable, Modifications [Line Items]
Recorded Investment	727,000	35,000	5,526,000	35,000
Below Market Interest Rate | Total commercial real estate
Financing Receivable, Modifications [Line Items]
Recorded Investment	487,000	157,000	7,461,000	2,247,000
Below Market Interest Rate | Total commercial real estate | Investment properties
Financing Receivable, Modifications [Line Items]
Recorded Investment	42,000	0	6,053,000	0
Below Market Interest Rate | Total commercial real estate | 1-4 family properties
Financing Receivable, Modifications [Line Items]
Recorded Investment	445,000	0	1,408,000	2,090,000
Below Market Interest Rate | Total commercial real estate | Land and development
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	157,000	0	157,000
Below Market Interest Rate | Total consumer
Financing Receivable, Modifications [Line Items]
Recorded Investment	1,365,000	930,000	7,158,000	930,000
Below Market Interest Rate | Total consumer | Home equity lines
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	172,000	0
Below Market Interest Rate | Total consumer | Consumer mortgages
Financing Receivable, Modifications [Line Items]
Recorded Investment	670,000	248,000	5,365,000	248,000
Below Market Interest Rate | Total consumer | Credit cards
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Below Market Interest Rate | Total consumer | Other consumer loans
Financing Receivable, Modifications [Line Items]
Recorded Investment	695,000	682,000	1,621,000	682,000
Term Extensions and/or Other Concessions
Financing Receivable, Modifications [Line Items]
Recorded Investment	9,216,000	10,842,000	17,015,000	18,370,000
Term Extensions and/or Other Concessions | Total commercial and industrial
Financing Receivable, Modifications [Line Items]
Recorded Investment	5,404,000	7,549,000	7,653,000	13,850,000
Term Extensions and/or Other Concessions | Total commercial and industrial | Commercial, financial and agricultural
Financing Receivable, Modifications [Line Items]
Recorded Investment	565,000	5,866,000	2,130,000	12,145,000
Term Extensions and/or Other Concessions | Total commercial and industrial | Owner-occupied
Financing Receivable, Modifications [Line Items]
Recorded Investment	4,839,000	1,683,000	5,523,000	1,705,000
Term Extensions and/or Other Concessions | Total commercial real estate
Financing Receivable, Modifications [Line Items]
Recorded Investment	837,000	1,724,000	5,330,000	2,372,000
Term Extensions and/or Other Concessions | Total commercial real estate | Investment properties
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	2,215,000	0
Term Extensions and/or Other Concessions | Total commercial real estate | 1-4 family properties
Financing Receivable, Modifications [Line Items]
Recorded Investment	766,000	964,000	1,259,000	1,477,000
Term Extensions and/or Other Concessions | Total commercial real estate | Land and development
Financing Receivable, Modifications [Line Items]
Recorded Investment	71,000	760,000	1,856,000	895,000
Term Extensions and/or Other Concessions | Total consumer
Financing Receivable, Modifications [Line Items]
Recorded Investment	2,975,000	1,569,000	4,032,000	2,148,000
Term Extensions and/or Other Concessions | Total consumer | Home equity lines
Financing Receivable, Modifications [Line Items]
Recorded Investment	191,000	0	339,000	0
Term Extensions and/or Other Concessions | Total consumer | Consumer mortgages
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	1,181,000	87,000	1,190,000
Term Extensions and/or Other Concessions | Total consumer | Credit cards
Financing Receivable, Modifications [Line Items]
Recorded Investment	0	0	0	0
Term Extensions and/or Other Concessions | Total consumer | Other consumer loans
Financing Receivable, Modifications [Line Items]
Recorded Investment	$ 2,784,000	$ 388,000	$ 3,606,000	$ 958,000

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Loss) (Changes in Accumulated Other Comprehensive Income (Loss) by Component (Net of Income Taxes)) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Changes in Accumulated Other Comprehensive Income (Loss) by Component [Roll Forward]
Balance			$ 2,961,566	$ 2,927,924
Other comprehensive income (loss), Net of Tax Amount	$ (18,000)	$ 8,269	(81,495)	16,063
Balance	3,040,073	2,997,078	3,040,073	2,997,078
Total
Changes in Accumulated Other Comprehensive Income (Loss) by Component [Roll Forward]
Balance	(125,720)	(47,865)	(54,754)	(55,659)
Other comprehensive income (loss) before reclassifications	(17,974)	3,397	(82,383)	15,850
Amounts reclassified from accumulated other comprehensive income (loss)	(26)	4,872	888	213
Other comprehensive income (loss), Net of Tax Amount	(18,000)	8,269	(81,495)	16,063
Reclassification from adoption of ASU 2018-02			(7,588)
Cumulative-effect adjustment from adoption of ASU 2016-01			117
Balance	(143,720)	(39,596)	(143,720)	(39,596)
Net unrealized losses on cash flow hedges
Changes in Accumulated Other Comprehensive Income (Loss) by Component [Roll Forward]
Balance	(12,137)	(12,137)	(12,137)	(12,217)
Other comprehensive income (loss) before reclassifications	0	0	0	0
Amounts reclassified from accumulated other comprehensive income (loss)	0	0	0	80
Other comprehensive income (loss), Net of Tax Amount	0	0	0	80
Reclassification from adoption of ASU 2018-02			0
Cumulative-effect adjustment from adoption of ASU 2016-01			0
Balance	(12,137)	(12,137)	(12,137)	(12,137)
Net unrealized gains (losses) on investment securities available for sale
Changes in Accumulated Other Comprehensive Income (Loss) by Component [Roll Forward]
Balance	(114,565)	(36,586)	(43,470)	(44,324)
Other comprehensive income (loss) before reclassifications	(17,940)	3,359	(82,349)	15,812
Amounts reclassified from accumulated other comprehensive income (loss)	0	4,893	960	178
Other comprehensive income (loss), Net of Tax Amount	(17,940)	8,252	(81,389)	15,990
Reclassification from adoption of ASU 2018-02			(7,763)
Cumulative-effect adjustment from adoption of ASU 2016-01			117
Balance	(132,505)	(28,334)	(132,505)	(28,334)
Post-retirement unfunded health benefit
Changes in Accumulated Other Comprehensive Income (Loss) by Component [Roll Forward]
Balance	982	858	853	882
Other comprehensive income (loss) before reclassifications	(34)	38	(34)	38
Amounts reclassified from accumulated other comprehensive income (loss)	(26)	(21)	(72)	(45)
Other comprehensive income (loss), Net of Tax Amount	(60)	17	(106)	(7)
Reclassification from adoption of ASU 2018-02			175
Cumulative-effect adjustment from adoption of ASU 2016-01			0
Balance	$ 922	$ 875	$ 922	$ 875

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive Income (Loss) (Narrative) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Class of Stock [Line Items]
Accumulated other comprehensive income (loss)	$ (143,720)	$ (54,754)
Net unrealized losses on cash flow hedges | Valuation Allowance of Deferred Tax Assets
Class of Stock [Line Items]
Accumulated other comprehensive income (loss)	(12,100)
Net unrealized gains (losses) on investment securities available for sale | Valuation Allowance of Deferred Tax Assets
Class of Stock [Line Items]
Accumulated other comprehensive income (loss)	$ (13,300)

Fair Value Accounting (Financia

Fair Value Accounting (Financial Instruments Measured At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	$ 3,883,574	$ 3,987,069
Mortgage-backed securities issued by U.S. Government agencies
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	100,883	120,440
Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	1,117,703	1,111,999
State and municipal securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale		180
Corporate debt and other debt securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	17,120	20,391
U.S. Treasury securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	120,639	82,674
Mortgage-backed securities issued by U.S. Government sponsored enterprises
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	2,489,365	2,640,523
Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	998	522
Investment securities available for sale	120,639	85,836
Private equity investments	0	0
Mutual funds held in rabbi trusts	14,100	14,140
GGL/SBA loans servicing asset	0	0
Derivative assets	0	0
Earnout liabilities	0	0
Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	7,851	3,298
Investment securities available for sale	3,760,970	3,899,298
Private equity investments	0	0
Mutual funds held in rabbi trusts	0	0
GGL/SBA loans servicing asset	0	0
Derivative assets	10,014	11,722
Earnout liabilities	0	0
Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0	0
Investment securities available for sale	1,965	1,935
Private equity investments	13,112	15,771
Mutual funds held in rabbi trusts	0	0
GGL/SBA loans servicing asset	3,761	4,101
Derivative assets	0	0
Earnout liabilities	23,000	11,348
Fair Value, Measurements, Recurring Basis
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	8,849	3,820
Mortgage loans held for sale	37,276	48,024
Investment securities available for sale	3,883,574	3,987,069
Private equity investments	13,112	15,771
Mutual funds held in rabbi trusts	14,100	14,140
GGL/SBA loans servicing asset	3,761	4,101
Derivative assets	10,014	11,722
Trading account liabilities	3,540	1,000
Earnout liabilities	23,000	11,348
Derivative liabilities	22,812	17,097
Fair Value, Measurements, Recurring Basis | U.S. Government agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	6,532
Investment securities available for sale	37,864	10,862
Fair Value, Measurements, Recurring Basis | Mortgage-backed securities issued by U.S. Government agencies
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	921	3,002
Investment securities available for sale	100,883	120,440
Fair Value, Measurements, Recurring Basis | Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	183	296
Investment securities available for sale	1,117,703	1,111,999
Fair Value, Measurements, Recurring Basis | State and municipal securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	177
Investment securities available for sale		180
Fair Value, Measurements, Recurring Basis | Corporate debt and other debt securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	1,036	522
Investment securities available for sale	17,120	20,391
Fair Value, Measurements, Recurring Basis | U.S. Treasury securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	120,639	82,674
Fair Value, Measurements, Recurring Basis | Mortgage-backed securities issued by U.S. Government sponsored enterprises
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	2,489,365	2,640,523
Fair Value, Measurements, Recurring Basis | Mutual funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mutual funds	3,118
Fair Value, Measurements, Recurring Basis | Interest rate contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	8,892	10,786
Derivative liabilities	20,822	12,638
Fair Value, Measurements, Recurring Basis | Mortgage derivatives
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	1,122	936
Derivative liabilities		129
Fair Value, Measurements, Recurring Basis | Visa derivative
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liabilities	1,990	4,330
Fair Value, Measurements, Recurring Basis | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	998	522
Mortgage loans held for sale	0	0
Investment securities available for sale	120,639	85,836
Private equity investments	0	0
Mutual funds held in rabbi trusts	14,100	14,140
GGL/SBA loans servicing asset	0	0
Derivative assets	0	0
Trading account liabilities	0	0
Earnout liabilities	0	0
Derivative liabilities	0	0
Fair Value, Measurements, Recurring Basis | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | U.S. Government agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0
Investment securities available for sale	0	0
Fair Value, Measurements, Recurring Basis | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | Mortgage-backed securities issued by U.S. Government agencies
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0	0
Investment securities available for sale	0	0
Fair Value, Measurements, Recurring Basis | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0	0
Investment securities available for sale	0	0
Fair Value, Measurements, Recurring Basis | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | State and municipal securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0
Investment securities available for sale		0
Fair Value, Measurements, Recurring Basis | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | Corporate debt and other debt securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	998	522
Investment securities available for sale	0	3,162
Fair Value, Measurements, Recurring Basis | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | U.S. Treasury securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	120,639	82,674
Fair Value, Measurements, Recurring Basis | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | Mortgage-backed securities issued by U.S. Government sponsored enterprises
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	0	0
Fair Value, Measurements, Recurring Basis | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | Mutual funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mutual funds	3,118
Fair Value, Measurements, Recurring Basis | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | Interest rate contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	0	0
Derivative liabilities	0	0
Fair Value, Measurements, Recurring Basis | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | Mortgage derivatives
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	0	0
Derivative liabilities		0
Fair Value, Measurements, Recurring Basis | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | Visa derivative
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liabilities	0	0
Fair Value, Measurements, Recurring Basis | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	7,851	3,298
Mortgage loans held for sale	37,276	48,024
Investment securities available for sale	3,760,970	3,899,298
Private equity investments	0	0
Mutual funds held in rabbi trusts	0	0
GGL/SBA loans servicing asset	0	0
Derivative assets	10,014	11,722
Trading account liabilities	3,540	1,000
Earnout liabilities	0	0
Derivative liabilities	20,822	12,767
Fair Value, Measurements, Recurring Basis | Significant Other Observable Inputs (Level 2) | U.S. Government agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	6,532
Investment securities available for sale	37,864	10,862
Fair Value, Measurements, Recurring Basis | Significant Other Observable Inputs (Level 2) | Mortgage-backed securities issued by U.S. Government agencies
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	921	3,002
Investment securities available for sale	100,883	120,440
Fair Value, Measurements, Recurring Basis | Significant Other Observable Inputs (Level 2) | Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	183	296
Investment securities available for sale	1,117,703	1,111,999
Fair Value, Measurements, Recurring Basis | Significant Other Observable Inputs (Level 2) | State and municipal securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	177
Investment securities available for sale		180
Fair Value, Measurements, Recurring Basis | Significant Other Observable Inputs (Level 2) | Corporate debt and other debt securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	38	0
Investment securities available for sale	15,155	15,294
Fair Value, Measurements, Recurring Basis | Significant Other Observable Inputs (Level 2) | U.S. Treasury securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	0	0
Fair Value, Measurements, Recurring Basis | Significant Other Observable Inputs (Level 2) | Mortgage-backed securities issued by U.S. Government sponsored enterprises
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	2,489,365	2,640,523
Fair Value, Measurements, Recurring Basis | Significant Other Observable Inputs (Level 2) | Mutual funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mutual funds	0
Fair Value, Measurements, Recurring Basis | Significant Other Observable Inputs (Level 2) | Interest rate contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	8,892	10,786
Derivative liabilities	20,822	12,638
Fair Value, Measurements, Recurring Basis | Significant Other Observable Inputs (Level 2) | Mortgage derivatives
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	1,122	936
Derivative liabilities		129
Fair Value, Measurements, Recurring Basis | Significant Other Observable Inputs (Level 2) | Visa derivative
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liabilities	0	0
Fair Value, Measurements, Recurring Basis | Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0	0
Mortgage loans held for sale	0	0
Investment securities available for sale	1,965	1,935
Private equity investments	13,112	15,771
Mutual funds held in rabbi trusts	0	0
GGL/SBA loans servicing asset	3,761	4,101
Derivative assets	0	0
Trading account liabilities	0	0
Earnout liabilities	23,000	11,348
Derivative liabilities	1,990	4,330
Fair Value, Measurements, Recurring Basis | Significant Unobservable Inputs (Level 3) | U.S. Government agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0
Investment securities available for sale	0	0
Fair Value, Measurements, Recurring Basis | Significant Unobservable Inputs (Level 3) | Mortgage-backed securities issued by U.S. Government agencies
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0	0
Investment securities available for sale	0	0
Fair Value, Measurements, Recurring Basis | Significant Unobservable Inputs (Level 3) | Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0	0
Investment securities available for sale	0	0
Fair Value, Measurements, Recurring Basis | Significant Unobservable Inputs (Level 3) | State and municipal securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0
Investment securities available for sale		0
Fair Value, Measurements, Recurring Basis | Significant Unobservable Inputs (Level 3) | Corporate debt and other debt securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0	0
Investment securities available for sale	1,965	1,935
Fair Value, Measurements, Recurring Basis | Significant Unobservable Inputs (Level 3) | U.S. Treasury securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	0	0
Fair Value, Measurements, Recurring Basis | Significant Unobservable Inputs (Level 3) | Mortgage-backed securities issued by U.S. Government sponsored enterprises
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale	0	0
Fair Value, Measurements, Recurring Basis | Significant Unobservable Inputs (Level 3) | Mutual funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mutual funds	0
Fair Value, Measurements, Recurring Basis | Significant Unobservable Inputs (Level 3) | Interest rate contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	0	0
Derivative liabilities	0	0
Fair Value, Measurements, Recurring Basis | Significant Unobservable Inputs (Level 3) | Mortgage derivatives
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	0	0
Derivative liabilities		0
Fair Value, Measurements, Recurring Basis | Significant Unobservable Inputs (Level 3) | Visa derivative
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liabilities	$ 1,990	$ 4,330

Fair Value Accounting (Changes

Fair Value Accounting (Changes In Fair Value Included In Consolidated Statements Of Income) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Mortgage loans held for sale	$ (569)	$ (104)	$ (414)	$ 850
Fair value	37,276		37,276		$ 48,024
Unpaid principal balance	36,505		36,505		46,839
Fair value less aggregate unpaid principal balance	$ 771		$ 771		$ 1,185

Fair Value Accounting (Change_2

Fair Value Accounting (Changes In Level 3 Fair Value Measurements) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Losses included in earnings attributable to the change in unrealized losses relating to assets/liabilities	$ 11,800,000	$ 2,100,000	$ 17,900,000	$ 7,700,000
GGL / SBA Loans Servicing Asset
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	4,186,000	4,297,000	4,101,000	0
Included in earnings	(561,000)	(27,000)	(1,295,000)	(721,000)
Unrealized gains (losses) included in OCI	0	0	0	0
Additions	136,000		955,000	539,000
Settlements	0	0	0
Sales and settlements				0
Transfer from amortization method to fair value				4,452,000
Measurement period adjustments related to Global One				0
Ending balance	3,761,000	4,270,000	3,761,000	4,270,000
Total net losses for the period included in earnings attributable to the change in unrealized losses relating to assets/liabilities still held	(561,000)	(27,000)	(1,295,000)	(721,000)
Earnout Liability
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	(11,348,000)	(13,941,000)	(11,348,000)	(14,000,000)
Included in earnings	(11,652,000)	(2,059,000)	(11,652,000)	(3,766,000)
Unrealized gains (losses) included in OCI	0	0	0	0
Additions	0		0	0
Settlements	0	0	0
Sales and settlements				0
Transfer from amortization method to fair value				0
Measurement period adjustments related to Global One				1,766,000
Ending balance	(23,000,000)	(16,000,000)	(23,000,000)	(16,000,000)
Total net losses for the period included in earnings attributable to the change in unrealized losses relating to assets/liabilities still held	(11,652,000)	(2,059,000)	(11,652,000)	(3,766,000)
Visa Derivative
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	(5,943,000)	(5,053,000)	(4,330,000)	(5,768,000)
Included in earnings	0	0	(2,328,000)	0
Unrealized gains (losses) included in OCI	0	0	0	0
Additions	0		0	0
Settlements	3,953,000	360,000	4,668,000
Sales and settlements				1,075,000
Transfer from amortization method to fair value				0
Measurement period adjustments related to Global One				0
Ending balance	(1,990,000)	(4,693,000)	(1,990,000)	(4,693,000)
Total net losses for the period included in earnings attributable to the change in unrealized losses relating to assets/liabilities still held	0	0	(2,328,000)	0
Investment Securities Available for Sale
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	1,857,000	1,927,000	1,935,000	1,796,000
Included in earnings	0	0	0	0
Unrealized gains (losses) included in OCI	108,000	(9,000)	30,000	122,000
Additions	0		0	0
Settlements	0	0	0
Sales and settlements				0
Transfer from amortization method to fair value				0
Measurement period adjustments related to Global One				0
Ending balance	1,965,000	1,918,000	1,965,000	1,918,000
Total net losses for the period included in earnings attributable to the change in unrealized losses relating to assets/liabilities still held	0	0	0	0
Private Equity Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	12,678,000	15,698,000	15,771,000	25,493,000
Included in earnings	434,000	(27,000)	(2,659,000)	(3,193,000)
Unrealized gains (losses) included in OCI	0	0	0	0
Additions	0		0	0
Settlements	0	0	0
Sales and settlements				(6,629,000)
Transfer from amortization method to fair value				0
Measurement period adjustments related to Global One				0
Ending balance	13,112,000	15,671,000	13,112,000	15,671,000
Total net losses for the period included in earnings attributable to the change in unrealized losses relating to assets/liabilities still held	$ 434,000	$ (27,000)	$ (2,659,000)	$ (3,193,000)

Fair Value Accounting (Fair Val

Fair Value Accounting (Fair Value Inputs, Assets, Quantitative Information) (Details) - Significant Unobservable Inputs (Level 3) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Measurements, Recurring Basis | Earnout Liabilities | Option pricing methods and Monte Carlo simulation
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Liabilities, fair value disclosure	$ 23,000	$ 11,348
Fair Value, Measurements, Recurring Basis | Visa derivative | Discounted cash flow analysis
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Liabilities, fair value disclosure	$ 1,990	$ 4,330
Fair Value, Measurements, Recurring Basis | Visa derivative | Discounted cash flow analysis | Minimum
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Estimated future monthly fees payable to the derivative counterparty, period	1 year	1 year
Fair Value, Measurements, Recurring Basis | Visa derivative | Discounted cash flow analysis | Maximum
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Estimated future monthly fees payable to the derivative counterparty, period	2 years	4 years
Fair Value, Measurements, Recurring Basis | Trust preferred securities | Discounted cash flow analysis
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Assets, fair value disclosure	$ 1,965	$ 1,935
Credit spread embedded in discount rate	3.89%	3.98%
Fair Value, Measurements, Recurring Basis | Private equity investments | Individual Analysis of Each Investee Company
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Assets, fair value disclosure	$ 13,112	$ 15,771
Fair Value, Measurements, Recurring Basis | GGL / SBA Loans Servicing Asset | Discounted cash flow analysis
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Assets, fair value disclosure	$ 3,761	$ 4,101
Discount rate	13.40%	13.16%
Prepayment speeds	8.64%	7.50%
Fair Value, Measurements, Nonrecurring Basis | Collateral dependent impaired loans | Third-party appraised value of collateral less estimated selling costs | Minimum
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Discount to appraised value	0.00%	0.00%
Estimated selling costs	0.00%	0.00%
Fair Value, Measurements, Nonrecurring Basis | Collateral dependent impaired loans | Third-party appraised value of collateral less estimated selling costs | Maximum
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Discount to appraised value	68.00%	50.00%
Estimated selling costs	10.00%	10.00%
Fair Value, Measurements, Nonrecurring Basis | Collateral dependent impaired loans | Third-party appraised value of collateral less estimated selling costs | Weighted Average
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Discount to appraised value	25.00%	15.00%
Estimated selling costs	7.00%	7.00%
Fair Value, Measurements, Nonrecurring Basis | Other loans held for sale | Third-party appraised value of collateral less estimated selling costs | Minimum
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Discount to appraised value		5.00%
Estimated selling costs		0.00%
Fair Value, Measurements, Nonrecurring Basis | Other loans held for sale | Third-party appraised value of collateral less estimated selling costs | Maximum
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Discount to appraised value		99.00%
Estimated selling costs		10.00%
Fair Value, Measurements, Nonrecurring Basis | Other loans held for sale | Third-party appraised value of collateral less estimated selling costs | Weighted Average
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Discount to appraised value		54.00%
Estimated selling costs		2.00%
Fair Value, Measurements, Nonrecurring Basis | Other real estate | Third-party appraised value of collateral less estimated selling costs | Minimum
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Discount to appraised value	0.00%	0.00%
Estimated selling costs	0.00%	0.00%
Fair Value, Measurements, Nonrecurring Basis | Other real estate | Third-party appraised value of collateral less estimated selling costs | Maximum
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Discount to appraised value	7.00%	85.00%
Estimated selling costs	10.00%	10.00%
Fair Value, Measurements, Nonrecurring Basis | Other real estate | Third-party appraised value of collateral less estimated selling costs | Weighted Average
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Discount to appraised value	4.00%	35.00%
Estimated selling costs	7.00%	7.00%
Fair Value, Measurements, Nonrecurring Basis | Other assets held for sale | Third-party appraised value less estimated selling costs or BOV | Minimum
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Discount to appraised value	0.00%	21.00%
Estimated selling costs	0.00%	0.00%
Fair Value, Measurements, Nonrecurring Basis | Other assets held for sale | Third-party appraised value less estimated selling costs or BOV | Maximum
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Discount to appraised value	42.00%	52.00%
Estimated selling costs	10.00%	10.00%
Fair Value, Measurements, Nonrecurring Basis | Other assets held for sale | Third-party appraised value less estimated selling costs or BOV | Weighted Average
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Discount to appraised value	42.00%	25.00%
Estimated selling costs	7.00%	7.00%

Fair Value Accounting (Assets A

Fair Value Accounting (Assets And Liabilities Measured At Fair Value On A Non-Recurring Basis) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	$ 169,622	$ 200,286
Other assets held for sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate	8,500	3,800
Fair Value, Measurements, Nonrecurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	17,270	3,603
Other loans held for sale	0	10,197
Other real estate	507	3,363
Other assets held for sale	302	5,334
Fair Value, Measurements, Nonrecurring Basis | Quoted Prices in Active Markets for Identical Assets (Level 1 )
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Other loans held for sale	0	0
Other real estate	0	0
Other assets held for sale	0	0
Fair Value, Measurements, Nonrecurring Basis | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Other loans held for sale	0	0
Other real estate	0	0
Other assets held for sale	0	0
Fair Value, Measurements, Nonrecurring Basis | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	17,270	3,603
Other loans held for sale	0	10,197
Other real estate	507	3,363
Other assets held for sale	$ 302	$ 5,334

Fair Value Accounting (Assets M

Fair Value Accounting (Assets Measured at Fair Value on Nonrecurring Basis) (Details) - Fair Value, Measurements, Nonrecurring Basis - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value adjustment	$ 1,223	$ 83	$ 4,594	$ 1,075
Other loans held for sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value adjustment	0	25,051	0	25,051
Other real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value adjustment	61	5,165	61	5,165
Other assets held for sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value adjustment	$ 0	$ 1,683	$ 499	$ 1,683

Fair Value Accounting (Carrying

Fair Value Accounting (Carrying And Estimated Fair Values Of Financial Instruments Carried On Balance Sheet) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Financial assets
Mortgage loans held for sale	$ 37,276	$ 48,024
Investment securities available for sale	3,883,574	3,987,069
Loans, net	25,325,666	24,538,196
Financial liabilities
Non-interest-bearing deposits	7,628,736	7,686,339
Non-time interest-bearing deposits	18,804,922	18,461,561
Total deposits	26,433,658	26,147,900
Federal funds purchased and securities sold under repurchase agreements	191,145	161,190
Other short-term borrowings	478,540	100,000
Long-term debt	1,656,909	1,606,138
Quoted Prices in Active Markets for Identical Assets (Level 1 )
Financial assets
Total cash, cash equivalents, restricted cash, and restricted cash equivalents	1,011,933	932,933
Trading account assets	998	522
Mortgage loans held for sale	0	0
Other loans held for sale	0
Investment securities available for sale	120,639	85,836
Private equity investments	0	0
Mutual funds	3,118
Mutual funds held in rabbi trusts	14,100	14,140
Loans, net	0	0
GGL/SBA loans servicing asset	0	0
Derivative assets	0	0
Financial liabilities
Trading account liabilities	0	0
Non-interest-bearing deposits	0	0
Non-time interest-bearing deposits	0	0
Time deposits	0	0
Total deposits	0	0
Federal funds purchased and securities sold under repurchase agreements	191,145	161,190
Other short-term borrowings	0	0
Long-term debt	0	0
Earnout liabilities	0	0
Derivative liabilities	0	0
Significant Other Observable Inputs (Level 2)
Financial assets
Total cash, cash equivalents, restricted cash, and restricted cash equivalents	0	0
Trading account assets	7,851	3,298
Mortgage loans held for sale	37,276	48,024
Other loans held for sale	0
Investment securities available for sale	3,760,970	3,899,298
Private equity investments	0	0
Mutual funds	0
Mutual funds held in rabbi trusts	0	0
Loans, net	0	0
GGL/SBA loans servicing asset	0	0
Derivative assets	10,014	11,722
Financial liabilities
Trading account liabilities	3,540	1,000
Non-interest-bearing deposits	7,628,736	7,686,339
Non-time interest-bearing deposits	13,847,104	13,941,814
Time deposits	4,937,216	4,523,661
Total deposits	26,413,056	26,151,814
Federal funds purchased and securities sold under repurchase agreements	0	0
Other short-term borrowings	475,000	100,000
Long-term debt	1,654,002	1,621,814
Earnout liabilities	0	0
Derivative liabilities	20,822	12,767
Significant Unobservable Inputs (Level 3)
Financial assets
Total cash, cash equivalents, restricted cash, and restricted cash equivalents	0	0
Trading account assets	0	0
Mortgage loans held for sale	0	0
Other loans held for sale	12	11,356
Investment securities available for sale	1,965	1,935
Private equity investments	13,112	15,771
Mutual funds	0
Mutual funds held in rabbi trusts	0	0
Loans, net	25,138,896	24,507,141
GGL/SBA loans servicing asset	3,761	4,101
Derivative assets	0	0
Financial liabilities
Trading account liabilities	0	0
Non-interest-bearing deposits	0	0
Non-time interest-bearing deposits	0	0
Time deposits	0	0
Total deposits	0	0
Federal funds purchased and securities sold under repurchase agreements	0	0
Other short-term borrowings	0	0
Long-term debt	0	0
Earnout liabilities	23,000	11,348
Derivative liabilities	1,990	4,330
Carrying Value
Financial assets
Total cash, cash equivalents, restricted cash, and restricted cash equivalents	1,011,933	932,933
Trading account assets	8,849	3,820
Mortgage loans held for sale	37,276	48,024
Other loans held for sale	12	11,356
Investment securities available for sale	3,883,574	3,987,069
Private equity investments	13,112	15,771
Mutual funds	3,118
Mutual funds held in rabbi trusts	14,100	14,140
Loans, net	25,325,666	24,538,196
GGL/SBA loans servicing asset	3,761	4,101
Derivative assets	10,014	11,722
Financial liabilities
Trading account liabilities	3,540	1,000
Non-interest-bearing deposits	7,628,736	7,686,339
Non-time interest-bearing deposits	13,847,104	13,941,814
Time deposits	4,957,818	4,519,747
Total deposits	26,433,658	26,147,900
Federal funds purchased and securities sold under repurchase agreements	191,145	161,190
Other short-term borrowings	475,000	100,000
Long-term debt	1,656,909	1,606,138
Earnout liabilities	23,000	11,348
Derivative liabilities	22,812	17,097
Fair Value
Financial assets
Total cash, cash equivalents, restricted cash, and restricted cash equivalents	1,011,933	932,933
Trading account assets	8,849	3,820
Mortgage loans held for sale	37,276	48,024
Other loans held for sale	12	11,356
Investment securities available for sale	3,883,574	3,987,069
Private equity investments	13,112	15,771
Mutual funds	3,118
Mutual funds held in rabbi trusts	14,100	14,140
Loans, net	25,138,896	24,507,141
GGL/SBA loans servicing asset	3,761	4,101
Derivative assets	10,014	11,722
Financial liabilities
Trading account liabilities	3,540	1,000
Non-interest-bearing deposits	7,628,736	7,686,339
Non-time interest-bearing deposits	13,847,104	13,941,814
Time deposits	4,937,216	4,523,661
Total deposits	26,413,056	26,151,814
Federal funds purchased and securities sold under repurchase agreements	191,145	161,190
Other short-term borrowings	475,000	100,000
Long-term debt	1,654,002	1,621,814
Earnout liabilities	23,000	11,348
Derivative liabilities	$ 22,812	$ 17,097

Derivative Instruments (Narrati

Derivative Instruments (Narrative) (Details) - USD ($)	Sep. 30, 2018	Dec. 31, 2017
Derivative [Line Items]
Collateral requirements	$ 31,100,000
Variation margin, amount reducing derivative asset	11,600,000	$ 1,500,000
Cash Flow Hedges
Derivative [Line Items]
Derivative instruments	0	0
Fair Value Hedges
Derivative [Line Items]
Derivative instruments	$ 0	$ 0

Derivative Instruments (Impact

Derivative Instruments (Impact Of Derivatives On Balance Sheet) (Details) - Derivatives not designated as hedging instruments - USD ($)	Sep. 30, 2018	Dec. 31, 2017
Derivative [Line Items]
Fair value of derivative assets	$ 10,014,000	$ 11,722,000
Fair value of derivative liabilities	22,812,000	17,097,000
Interest rate contracts
Derivative [Line Items]
Derivative, Notional Amount	1,667,397,000	1,466,059,000
Fair value of derivative assets	8,892,000	10,786,000
Fair value of derivative liabilities	20,822,000	12,638,000
Mortgage derivatives | Interest rate lock commitments
Derivative [Line Items]
Derivative, Notional Amount	59,289,000	49,304,000
Fair value of derivative assets	875,000	936,000
Fair value of derivative liabilities	0	0
Mortgage derivatives | Frward commitments to sell fixed-rate mortgage loans
Derivative [Line Items]
Derivative, Notional Amount	85,500,000	72,500,000
Fair value of derivative assets	247,000	0
Fair value of derivative liabilities	0	129,000
Visa derivative
Derivative [Line Items]
Fair value of derivative assets	0	0
Fair value of derivative liabilities	$ 1,990,000	$ 4,330,000

Derivative Instruments (Effect

Derivative Instruments (Effect Of Fair Value Hedges On Consolidated Statements Of Income) (Details) - Derivatives not designated as hedging instruments - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Derivative [Line Items]
Gain (Loss) Recognized in Income	$ 69	$ (455)	$ (2,021)	$ (2,529)
Interest rate contracts | Other non-interest income
Derivative [Line Items]
Gain (Loss) Recognized in Income	1	(4)	(8)	(5)
Mortgage derivatives | Interest rate lock commitments | Mortgage banking income
Derivative [Line Items]
Gain (Loss) Recognized in Income	(427)	(180)	(61)	(595)
Mortgage derivatives | Frward commitments to sell fixed-rate mortgage loans | Mortgage banking income
Derivative [Line Items]
Gain (Loss) Recognized in Income	495	(271)	376	(1,929)
Visa derivative | Other non-interest expense
Derivative [Line Items]
Gain (Loss) Recognized in Income	$ 0	$ 0	$ (2,328)	$ 0

Shareholders' Equity (Details)

Shareholders' Equity (Details) - USD ($)	Aug. 01, 2018	Jun. 21, 2018	Oct. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Oct. 31, 2018	Sep. 30, 2018	Sep. 30, 2017	Jan. 23, 2018
Redemption of Series C Preferred Stock
Proceeds from issuance of stock									$ 195,138,000	$ 0
Cash dividends paid on preferred stock										7,678,000
Extinguishment loss				$ 9,729,000		$ 2,559,000			14,848,000	7,678,000
Authorized amount											$ 150,000,000
Value repurchased							$ 134,800,000		134,804,000	$ 135,914,000
Shares repurchased (in shares)							2,600,000
Shares repurchased, average cost per share (in dollars per share)							$ 51.85
Remaining authorized repurchase amount				$ 15,200,000			$ 15,200,000		15,200,000
Subsequent Event
Redemption of Series C Preferred Stock
Value repurchased			$ 15,200,000
Shares repurchased (in shares)			345,000					2,900,000
Shares repurchased, average cost per share (in dollars per share)								$ 50.96
Series D Preferred Stock
Redemption of Series C Preferred Stock
Proceeds from issuance of stock		$ 200,000,000
Cash dividends paid on preferred stock									3,150,000
Series C Preferred Stock
Redemption of Series C Preferred Stock
Preferred stock, redemption price per share (in usd per share)	$ 25
Cash dividends paid on preferred stock	$ 2,600,000								7,678,000
Value repurchased									130,000,000
Series C Preferred Stock | Preferred Stock
Redemption of Series C Preferred Stock
Sale of stock (in dollars per share)		$ 25
Consideration received on transaction		$ 195,100,000
Redemption period from regulatory capital treatment		90 days
Stock redeemed during period (in shares)	5,200,000
Stock redeemed during period	$ 130,000,000
Extinguishment loss					$ 4,000,000
Value repurchased									$ 125,980,000
Series C Preferred Stock | Preferred Stock | Till June 20, 2023
Redemption of Series C Preferred Stock
Preferred stock, dividend rate, percentage		6.30%
Series C Preferred Stock | Preferred Stock | From June 21, 2023 | Three-month LIBOR
Redemption of Series C Preferred Stock
Preferred stock, dividend rate, percentage		3.352%

Net Income Per Common Share (Sc

Net Income Per Common Share (Schedule Of Basic And Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Basic Net Income Per Common Share:
Net income available to common shareholders	$ 99,330	$ 95,448	$ 308,559	$ 238,190
Weighted average common shares outstanding (in shares)	117,241	120,900	118,096	121,796
Net income per common share, basic (in dollars per share)	$ 0.85	$ 0.79	$ 2.61	$ 1.96
Diluted Net Income Per Common Share:
Net income available to common shareholders	$ 99,330	$ 95,448	$ 308,559	$ 238,190
Weighted average common shares outstanding (in shares)	117,241	120,900	118,096	121,796
Potentially dilutive shares from outstanding equity-based awards and earnout payments (in shares)	854	914	751	832
Weighted average number of diluted common shares (in shares)	118,095	121,814	118,847	122,628
Net income per common share, diluted (in dollars per share)	$ 0.84	$ 0.78	$ 2.60	$ 1.94

Net Income Per Common Share (Na

Net Income Per Common Share (Narrative) (Details) - shares shares in Millions	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Earnings Per Share [Abstract]
Potentially dilutive shares (in shares)	2.2	2.2

Share-based Compensation (Detai

Share-based Compensation (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 4.2	$ 3.7	$ 12.5	$ 10.6
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Other equity compensation, shares granted (in shares)			0
Options outstanding (in options)	643,000		643,000
Weighted-average exercise price, options (in dollars per share)	$ 16.94		$ 16.94
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)			3 years
Other equity compensation, shares granted (in shares)			236,000
Weighted-average exercise price, shares granted during period (in dollars per share)			$ 47.69
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Other equity compensation, shares granted (in shares)			87,000
Weighted-average exercise price, shares granted during period (in dollars per share)			$ 47.67
Market Restricted Stock Units (MRSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)			3 years
Other equity compensation, shares granted (in shares)			58,000
Weighted-average exercise price, shares granted during period (in dollars per share)			$ 47.67
Market Restricted Stock Units (MRSUs) | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range based on shareholder return	75.00%		75.00%
Market Restricted Stock Units (MRSUs) | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range based on shareholder return	125.00%		125.00%
Performance Share Units (PSUs) | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range based on return on average assets (ROAA)	0.00%		0.00%
Performance Share Units (PSUs) | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range based on return on average assets (ROAA)	150.00%		150.00%
Non-Vested Synovus Shares And Restricted Share Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Other equity compensation, non-vested shares outstanding (in shares)	909,000		909,000
Weighted-average exercise price, non-vested shares outstanding (in dollars per share)	$ 40.86		$ 40.86
2013 Omnibus Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of authorized but unissued common stock reserved for future grants (in shares)	8,600,000		8,600,000
Equivalents authorized (in shares)	4,900,000		4,900,000
Contractual term (years)			10 years
Minimum age of plan participants			65 years
Plan participants, minimum period of service			10 years
2013 Omnibus Plan | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)			3 years
2013 Omnibus Plan | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)			5 years
2013 Omnibus Plan | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share equivalents ratio (in shares)	1		1
2013 Omnibus Plan | Value Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share equivalents ratio (in shares)	2		2

Income Taxes (Provision for Inc

Income Taxes (Provision for Income Tax and Effective Tax Rate) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Income before income taxes	$ 128,008	$ 152,675	$ 403,502	$ 376,171
Income tax expense	$ 18,949	$ 54,668	$ 80,095	$ 130,303
Effective tax rate	14.80%	35.80%	19.80%	34.60%

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Discrete tax benefits	$ 12,700
Tax Cuts and Jobs Act of 2017, provisional income tax expense (benefit)	(3,900)				$ 47,200
Return to provision benefit associated with finalizing tax returns	5,500
Benefit associated with insignificant adjustments to tax returns from prior years	3,300
Benefits associated with the exercise and vesting of employee equity awards			$ 2,800
Income tax expense (benefit)	$ 18,949	$ 54,668	$ 80,095	$ 130,303

Non-interest Income (Details)

Non-interest Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation of Revenue [Line Items]
Non-interest income	$ 55,849	$ 52,320	$ 166,514	$ 155,643
Other revenues	15,819	83,115	45,587	120,331
Total non-interest income	71,668	135,435	212,101	275,974
Service charges on deposit accounts
Disaggregation of Revenue [Line Items]
Non-interest income	20,582	20,678	60,521	61,048
Fiduciary and asset management fees
Disaggregation of Revenue [Line Items]
Non-interest income	13,462	12,615	40,881	37,290
Card fees
Disaggregation of Revenue [Line Items]
Non-interest income	10,608	9,729	31,640	29,614
Brokerage revenue
Disaggregation of Revenue [Line Items]
Non-interest income	9,329	7,511	26,924	21,947
Insurance revenue
Disaggregation of Revenue [Line Items]
Non-interest income	1,148	1,059	4,240	3,424
Other fees
Disaggregation of Revenue [Line Items]
Non-interest income	720	728	2,308	2,320
Community Banking
Disaggregation of Revenue [Line Items]
Non-interest income	5,868	5,823	17,692	17,675
Other revenues	1,142	2,642	6,983	7,283
Total non-interest income	7,010	8,465	24,675	24,958
Community Banking | Service charges on deposit accounts
Disaggregation of Revenue [Line Items]
Non-interest income	5,660	5,613	17,064	17,028
Community Banking | Fiduciary and asset management fees
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Community Banking | Card fees
Disaggregation of Revenue [Line Items]
Non-interest income	208	210	628	647
Community Banking | Brokerage revenue
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Community Banking | Insurance revenue
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Community Banking | Other fees
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Corporate Banking
Disaggregation of Revenue [Line Items]
Non-interest income	475	432	1,460	1,319
Other revenues	1,836	1,460	5,417	5,836
Total non-interest income	2,311	1,892	6,877	7,155
Corporate Banking | Service charges on deposit accounts
Disaggregation of Revenue [Line Items]
Non-interest income	475	432	1,460	1,319
Corporate Banking | Fiduciary and asset management fees
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Corporate Banking | Card fees
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Corporate Banking | Brokerage revenue
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Corporate Banking | Insurance revenue
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Corporate Banking | Other fees
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Retail Banking
Disaggregation of Revenue [Line Items]
Non-interest income	24,646	24,006	72,809	71,486
Other revenues	1,645	1,574	4,887	4,756
Total non-interest income	26,291	25,580	77,696	76,242
Retail Banking | Service charges on deposit accounts
Disaggregation of Revenue [Line Items]
Non-interest income	13,792	14,024	40,310	40,994
Retail Banking | Fiduciary and asset management fees
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Retail Banking | Card fees
Disaggregation of Revenue [Line Items]
Non-interest income	10,400	9,519	31,012	28,967
Retail Banking | Brokerage revenue
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Retail Banking | Insurance revenue
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Retail Banking | Other fees
Disaggregation of Revenue [Line Items]
Non-interest income	454	463	1,487	1,525
Financial Management Services
Disaggregation of Revenue [Line Items]
Non-interest income	23,939	21,185	72,045	62,661
Other revenues	5,994	6,558	17,402	19,971
Total non-interest income	29,933	27,743	89,447	82,632
Financial Management Services | Service charges on deposit accounts
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Financial Management Services | Fiduciary and asset management fees
Disaggregation of Revenue [Line Items]
Non-interest income	13,462	12,615	40,881	37,290
Financial Management Services | Card fees
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Financial Management Services | Brokerage revenue
Disaggregation of Revenue [Line Items]
Non-interest income	9,329	7,511	26,924	21,947
Financial Management Services | Insurance revenue
Disaggregation of Revenue [Line Items]
Non-interest income	1,148	1,059	4,240	3,424
Financial Management Services | Other fees
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Other
Disaggregation of Revenue [Line Items]
Non-interest income	921	874	2,508	2,502
Other revenues	5,202	70,881	10,898	82,485
Total non-interest income	6,123	71,755	13,406	84,987
Other | Service charges on deposit accounts
Disaggregation of Revenue [Line Items]
Non-interest income	655	609	1,687	1,707
Other | Fiduciary and asset management fees
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Other | Card fees
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Other | Brokerage revenue
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Other | Insurance revenue
Disaggregation of Revenue [Line Items]
Non-interest income	0	0	0	0
Other | Other fees
Disaggregation of Revenue [Line Items]
Non-interest income	$ 266	$ 265	$ 821	$ 795

Commitments and Contingencies_2

Commitments and Contingencies (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Loss Contingencies [Line Items]
Contractual amount net of risk participations	$ 70,000,000		$ 70,000,000		$ 77,000,000
Minimum
Loss Contingencies [Line Items]
Total unfunded lending commitments and letters of credit	0		0
Maximum
Loss Contingencies [Line Items]
Total unfunded lending commitments and letters of credit	5,000,000		5,000,000
Guarantee obligations
Loss Contingencies [Line Items]
Total unfunded lending commitments and letters of credit	9,991,977,000		9,991,977,000		9,080,108,000
Maximum potential exposure for sponsored transactions	17,690,000,000	$ 15,840,000,000	52,040,000,000	$ 46,260,000,000
Letters of credit
Loss Contingencies [Line Items]
Total unfunded lending commitments and letters of credit	167,969,000		167,969,000		153,372,000
Commitments to fund commercial and industrial loans
Loss Contingencies [Line Items]
Total unfunded lending commitments and letters of credit	5,688,192,000		5,688,192,000		5,090,827,000
Commitments to fund commercial real estate, construction, and land development loans
Loss Contingencies [Line Items]
Total unfunded lending commitments and letters of credit	1,763,006,000		1,763,006,000		1,567,583,000
Commitments under home equity lines of credit
Loss Contingencies [Line Items]
Total unfunded lending commitments and letters of credit	1,211,861,000		1,211,861,000		1,137,714,000
Unused credit card lines
Loss Contingencies [Line Items]
Total unfunded lending commitments and letters of credit	766,521,000		766,521,000		779,254,000
Other loan commitments
Loss Contingencies [Line Items]
Total unfunded lending commitments and letters of credit	$ 394,428,000		$ 394,428,000		$ 351,358,000

Pending Acquisition and Pendi_2

Pending Acquisition and Pending Branch Sales (Details) $ / shares in Units, $ in Thousands	Sep. 30, 2018USD ($)branch$ / shares	Aug. 28, 2018USD ($)branch	Jul. 23, 2018branch$ / shares	Jun. 30, 2018USD ($)	Dec. 31, 2017USD ($)$ / shares
Pending Acquisition of FCB Financial Holdings, Inc.
Assets	$ 32,075,120				$ 31,221,837
Common stock, par value (in dollars per share) | $ / shares	$ 1				$ 1
Number of branches | branch	249
Loans	$ 25,325,666				$ 24,538,196
Deposits	$ 26,433,658				$ 26,147,900
Plan | Disposed of by Sale
Pending Acquisition of FCB Financial Holdings, Inc.
Number of branches disposed | branch		3
Loans		$ 138,000
Deposits		107,000
Deposit premium		$ 14,500
Plan | Disposed of by Sale | Mobile, Alabama
Pending Acquisition of FCB Financial Holdings, Inc.
Number of branches disposed | branch		2
Plan | Disposed of by Sale | Daphne, Alabama
Pending Acquisition of FCB Financial Holdings, Inc.
Number of branches disposed | branch		1
FCB Financial Holdings, Inc.
Pending Acquisition of FCB Financial Holdings, Inc.
Assets				$ 12,190,000
Common stock, par value (in dollars per share) | $ / shares			$ 0.001
FCB Financial Holdings, Inc.
Pending Acquisition of FCB Financial Holdings, Inc.
Number of branches | branch			50
FCB Financial Holdings, Inc. | Synovus Brand
Pending Acquisition of FCB Financial Holdings, Inc.
Common stock, par value (in dollars per share) | $ / shares			$ 1
Conversion ratio for common share			1.055