First Interstate BancSystem (FIBK) 10-Q 6 May 16 2015 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information	3 Months Ended
	Mar. 31, 2016shares
Entity Registrant Name	FIRST INTERSTATE BANCSYSTEM INC
Entity Central Index Key	860,413
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2016
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q1
Amendment Flag	false
Class A Common Stock
Entity Common Stock, Shares Outstanding	21,007,483
Class B Common Stock
Entity Common Stock, Shares Outstanding	23,700,002

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Assets
Cash and due from banks	$ 113,755	$ 132,595
Federal funds sold	196	563
Interest bearing deposits in banks	541,577	647,299
Total cash and cash equivalents	655,528	780,457
Investment securities:
Available-for-sale	1,563,350	1,456,840
Held-to-maturity (estimated fair values of $593,904 and $607,550 at March 31, 2016 and December 31, 2015, respectively)	581,390	600,665
Total investment securities	2,144,740	2,057,505
Loans held for investment	5,191,469	5,193,321
Mortgage loans held for sale	52,989	52,875
Total loans	5,244,458	5,246,196
Less allowance for loan losses	79,924	76,817
Net loans	5,164,534	5,169,379
Goodwill	204,481	204,523
Premises and equipment, net of accumulated depreciation	188,714	190,812
Company-owned life insurance	188,396	187,253
Other real estate owned (OREO)	9,257	6,254
Accrued interest receivable	26,907	27,729
Core deposit intangibles, net of accumulated amortization	9,762	10,589
Mortgage servicing rights, net of accumulated amortization and impairment reserve	15,574	15,621
Other assets	82,787	78,074
Total assets	8,690,680	8,728,196
Deposits:
Non-interest bearing	1,860,472	1,823,716
Interest bearing	5,246,991	5,265,221
Total deposits	7,107,463	7,088,937
Securities sold under repurchase agreements	465,523	510,635
Accounts payable and accrued expenses	48,102	53,042
Accrued interest payable	5,184	4,960
Deferred tax liability	11,977	9,765
Long-term debt	27,907	27,885
Other borrowed funds	33	2
Subordinated debentures held by subsidiary trusts	82,477	82,477
Total liabilities	7,748,666	7,777,703
Stockholders' equity:
Nonvoting noncumulative preferred stock without par value; authorized 100,000 shares; no shares issued and outstanding as of March 31, 2016 or December 31, 2015	0	0
Common stock	288,782	311,720
Retained earnings	648,631	638,367
Accumulated other comprehensive income, net	4,601	406
Total stockholders' equity	942,014	950,493
Total liabilities and stockholders' equity	$ 8,690,680	$ 8,728,196

Consolidated Balance Sheets (U3

Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Investment securities:
Held-to-Maturity, Estimated Fair Value	$ 593,904	$ 607,550
Stockholders' equity:
Nonvoting noncumulative preferred stock, par value	$ 0	$ 0
Nonvoting noncumulative preferred stock, authorized shares	100,000	100,000
Nonvoting noncumulative preferred stock, issued shares	0	0
Nonvoting noncumulative preferred stock, outstanding shares	0	0

Consolidated Statements of Inco

Consolidated Statements of Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Interest income:
Interest and fees on loans	$ 62,816	$ 59,371
Interest and dividends on investment securities:
Taxable	8,038	7,971
Exempt from federal taxes	879	1,059
Interest on deposits in banks	645	389
Interest on federal funds sold	2	2
Total interest income	72,380	68,792
Interest expense:
Interest on deposits	3,228	3,309
Interest on securities sold under repurchase agreements	90	54
Interest on long-term debt	449	515
Interest on subordinated debentures held by subsidiary trusts	663	589
Total interest expense	4,430	4,467
Net interest income	67,950	64,325
Provision for loan losses	4,000	1,095
Net interest income after provision for loan losses	63,950	63,230
Non-interest income:
Payment services revenues	7,991	7,372
Other service charges, commissions and fees	2,608	2,495
Income from the origination and sale of loans	6,141	5,906
Investment Advisory, Management and Administrative Fees	4,575	4,937
Service charges on deposit accounts	4,463	3,944
Investment securities gains, net	(21)	6
Other income	1,486	3,122
Total non-interest income	27,243	27,782
Non-interest expense:
Salaries and wages	24,682	25,349
Employee benefits	8,802	7,780
Occupancy, net	4,664	4,492
Furniture and equipment	2,256	3,793
Outsourced technology services	4,832	2,463
OREO expense, net of income	(39)	(61)
Professional fees	1,308	1,301
FDIC insurance premiums	1,258	1,142
Mortgage servicing rights amortization	634	619
Mortgage servicing rights impairment recovery	15	(15)
Core deposit intangibles amortization	827	855
Other expenses	11,623	11,804
Non-core acquisition expenses	0	70
Total non-interest expense	60,862	59,592
Income before income tax expense	30,331	31,420
Income tax expense	10,207	10,440
Net income	$ 20,124	$ 20,980
Basic earnings per common share	$ 0.45	$ 0.46
Diluted earnings per common share	$ 0.45	$ 0.46

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Net income	$ 20,124	$ 20,980
Other comprehensive income (loss), before tax:
Change in net unrealized gains/losses during period	8,613	10,608
Reclassification adjustment for net (gains) losses included in income	21	(6)
Change in unamortized loss on available-for-sale securities transferred into held-to-maturity	465	451
Unrealized loss on derivatives	(2,197)	0
Defined benefit post-retirement benefits plans:
Change in net actuarial loss	15	15
Other comprehensive income (loss), before tax	6,917	11,068
Deferred tax benefit (expense) related to other comprehensive income	(2,722)	(4,355)
Other comprehensive income (loss), net of tax	4,195	6,713
Comprehensive income, net of tax	$ 24,319	$ 27,693

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders Equity (Unaudited) - USD ($) $ in Thousands	Total	Common stock	Retained earnings	Accumulated other comprehensive income
Beginning Balance at Dec. 31, 2014	$ 908,924	$ 323,596	$ 587,862	$ (2,534)
Comprehensive income:
Net income	20,980	0	20,980	0
Other comprehensive income, net of tax	6,713	0	0	6,713
Common stock transactions:
Common shares purchased and retired 789,743 and 387,967 in 2015 and 2014, respectively	(15,264)	(15,264)	0	0
Stock Issued During Period, 21,414 and 1,402,811 in 2015 and 2014, respectively	0	0	0	0
6,484 and 17,741 non-vested common shares forfeited in 2015 and 2014 respectively	0	0	0	0
158,828 and 372,880 stock options exercised, net of 58,996 and 166,780 shares tendered in payment of option price and income tax withholding amounts in 2015 and 2014 respectively	900	900	0	0
Tax benefit of stock-based compensation	480	480	0	0
Stock-based compensation expense	832	832	0	0
Cash dividends declared:
Common ($0.40 per share) in 2015 and ($0.32 per share) in 2014	(9,115)	0	(9,115)	0
Ending Balance at Mar. 31, 2015	914,450	310,544	599,727	4,179
Beginning Balance at Dec. 31, 2015	950,493	311,720	638,367	406
Comprehensive income:
Net income	20,124	0	20,124	0
Other comprehensive income, net of tax	4,195	0	0	4,195
Common stock transactions:
Common shares purchased and retired 789,743 and 387,967 in 2015 and 2014, respectively	(25,309)	(25,309)	0	0
Non-vested common shares issued 169,577 and 147,876 in 2015 and 2014 respectively	0	0	0	0
6,484 and 17,741 non-vested common shares forfeited in 2015 and 2014 respectively	0	0	0	0
158,828 and 372,880 stock options exercised, net of 58,996 and 166,780 shares tendered in payment of option price and income tax withholding amounts in 2015 and 2014 respectively	996	996	0	0
Tax benefit of stock-based compensation	420	420	0	0
Stock-based compensation expense	955	955	0	0
Cash dividends declared:
Common ($0.40 per share) in 2015 and ($0.32 per share) in 2014	(9,860)	0	(9,860)	0
Ending Balance at Mar. 31, 2016	$ 942,014	$ 288,782	$ 648,631	$ 4,601

Consolidated Statements of Cha7

Consolidated Statements of Changes in Stockholders Equity (Unaudited) (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Common stock
Common stock transactions:
Common shares purchased and retired	967,965	588,409
Common shares issued	0	0
Non-vested common shares issued	182,544	156,956
Non-vested common shares forfeited	12,347	838
Stock options exercised	77,028	73,344
Shares tendered in payment of option price and income tax withholding amounts	34,816	22,042
Retained earnings
Cash dividends declared:
Common (in dollars per share)	$ 0.22	$ 0.20

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Cash flows from operating activities:
Net income	$ 20,124	$ 20,980
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	4,000	1,095
Net (gain) loss on disposal of property and equipment	142	(204)
Depreciation and amortization	4,679	4,544
Net premium amortization on investment securities	3,238	3,684
Net gains on investment securities transactions	21	(6)
Net gains on sales of mortgage loans held for sale	(4,588)	(4,321)
Net gain on sale of OREO	(102)	(750)
Write-downs of OREO and other assets pending disposal	17	106
Net reversal of impairment of mortgage servicing rights	15	(15)
Deferred income tax expense	(517)	4,914
Net increase in cash surrender value of company-owned life insurance policies	(1,143)	(920)
Stock-based compensation expense	955	832
Tax benefits from stock-based compensation expense	420	480
Excess tax benefits from stock-based compensation	(307)	(292)
Originations of loans held for sale	(195,444)	(239,527)
Proceeds from sales of loans held for sale	199,316	228,259
Changes in operating assets and liabilities:
Increase in interest receivable	822	(179)
Increase in other assets	(4,567)	(3,630)
Decrease in accrued interest payable	224	(720)
Decrease in accounts payable and accrued expenses	(7,128)	(15,682)
Net cash provided by operating activities	20,177	(1,352)
Cash flows from investing activities:
Purchases of held-to-maturity investment securities	(4,870)	(11,733)
Purchases of available-for-sale investment securities	(254,098)	(153,953)
Proceeds from maturities and paydowns of held-to-maturity investment securities	23,925	22,826
Proceeds from maturities and paydowns of available-for-sale investment securities	153,703	95,996
Extensions of credit to customers, net of repayments	(5,677)	(20,050)
Recoveries of loans charged-off	3,409	1,901
Proceeds from sales of OREO	309	2,321
Capital expenditures, net of sales	(1,408)	(382)
Net cash used in investing activities	(84,707)	(63,074)
Cash flows from financing activities:
Net increase (decrease) in deposits	18,526	(38,053)
Net increase (decrease) in repurchase agreements	(45,112)	(40,177)
Net increase (decrease) in other borrowed funds	31	(5)
Repayments of long-term debt	(15)	(15)
Advances on long-term debt	37	4,996
Proceeds from issuance of common stock	996	900
Excess tax benefits from stock-based compensation	307	292
Purchase and retirement of common stock	(25,309)	(15,264)
Dividends paid to common stockholders	(9,860)	(9,115)
Net cash provided by (used in) financing activities	(60,399)	(96,441)
Net increase (decrease) in cash and cash equivalents	(124,929)	(160,867)
Cash and cash equivalents at beginning of period	780,457	798,670
Cash and cash equivalents at end of period	655,528	637,803
Supplemental disclosures of cash flow information:
Cash paid during the period for income taxes	4,206	5,100
Cash paid during the period for interest expense	15,390	5,187
Transfer of loans to other real estate owned	3,227	3,257
Capitalization of internally originated mortgage servicing rights	$ 602	$ 659

Basis of Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	In the opinion of management, the accompanying unaudited consolidated financial statements of First Interstate BancSystem, Inc. and subsidiaries (the “Company”) contain all adjustments (all of which are of a normal recurring nature) necessary to present fairly the financial position of the Company at March 31, 2016 and December 31, 2015 , and the results of operations and cash flows for each of the three month periods ended March 31, 2016 and 2015 in conformity with U.S. generally accepted accounting principles. The balance sheet information at December 31, 2015 is derived from audited consolidated financial statements. Certain reclassifications, none of which were material, have been made to conform prior year financial statements to the March 31, 2016 presentation. These reclassifications did not change previously reported net income or stockholders’ equity. These unaudited consolidated financial statements should be read in conjunction with the audited consolidated financial statements and related notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2015 . Operating results for the three months ended March 31, 2016 are not necessarily indicative of the results that may be expected for the year ending December 31, 2016 .

Acquisitions

Acquisitions	3 Months Ended
	Mar. 31, 2016
Business Combinations [Abstract]
Acquisitions	Acquisitions Flathead Bank. On April 6, 2016 , the Company's bank subsidiary, First Interstate Bank, entered into a stock purchase agreement to acquire all of the outstanding stock of Flathead Bank of Bigfork ("Flathead Bank"), a Montana-based bank wholly owned by Flathead Holding Company. With total assets of $ 231,574 as of December 31, 2015, Flathead Bank operates seven branches in western and northwestern Montana. Upon closing of the transaction, which is expected to occur during the third quarter of 2016 subject to regulatory approval, all Flathead Bank branches will become branches of First Interstate Bank. Pursuant to the Purchase Agreement, First Interstate Bank will pay cash consideration of approximately $ 34,237 for the stock, subject to certain financial performance and other adjustments, the amount of which will be determined prior to the closing date of the transaction. Absarokee Bancorporation, Inc. On July 24, 2015 , the Company acquired all of the outstanding stock of Absarokee Bancorporation, Inc. ("Absarokee"), a Montana-based bank holding company that operated one subsidiary bank, United Bank. The Company merged United Bank with and into First Interstate Bank immediately subsequent to the acquisition. During March 2016 , the Company completed its review of Absarokee's tax items and finalized the fair value of the acquired deferred tax asset. Finalization of provisional estimates resulted in a $ 42 decrease in goodwill.

Investment Securities

Investment Securities	3 Months Ended
	Mar. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Investment Securities	he amortized cost and approximate fair values of investment securities are summarized as follows: March 31, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Available-for-Sale: U.S. Treasury notes $ 3,911 $ 24 $ — $ 3,935 Obligations of U.S. government agencies 530,037 1,719 (324 ) 531,432 U.S. agency residential mortgage-backed securities & collateralized mortgage obligations 1,010,675 14,550 (862 ) 1,024,363 Private mortgage-backed securities 144 1 (2 ) 143 Other investments 3,450 27 — 3,477 Total $ 1,548,217 $ 16,321 $ (1,188 ) $ 1,563,350 March 31, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Held-to-Maturity: State, county and municipal securities $ 167,975 $ 5,553 $ (14 ) $ 173,514 Corporate securities 51,918 292 (61 ) 52,149 U.S agency residential mortgage-backed securities & collateralized mortgage obligations 341,434 11,640 (5,145 ) 347,929 Obligations of U.S. government agencies 19,737 248 — 19,985 Other investments 326 1 — 327 Total $ 581,390 $ 17,734 $ (5,220 ) $ 593,904 December 31, 2015 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Available-for-Sale: U.S. Treasury notes $ 3,912 $ 3 $ (4 ) $ 3,911 Obligations of U.S. government agencies 521,079 712 (1,610 ) 520,181 U.S. agency residential mortgage-backed securities & collateralized mortgage obligations 921,699 9,448 (2,101 ) 929,046 Private mortgage-backed securities 156 1 (1 ) 156 Other investments 3,550 5 (9 ) 3,546 Total $ 1,450,396 $ 10,169 $ (3,725 ) $ 1,456,840 December 31, 2015 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Held-to-Maturity: State, county and municipal securities $ 173,785 $ 5,103 $ (227 ) $ 178,661 Corporate securities 50,046 64 (220 ) 49,890 U.S. agency residential mortgage-backed securities & collateralized mortgage obligations 356,742 7,686 (5,420 ) 359,008 Obligations of U.S. government agencies 19,738 — (102 ) 19,636 Other investments 354 1 — 355 Total $ 600,665 $ 12,854 $ (5,969 ) $ 607,550 Gross realized gains and losses from the disposition of investment securities are summarized in the following table: Three Months Ended March 31, 2016 2015 Gross realized gains $ 57 $ 6 Gross realized losses (78 ) — The following tables show the gross unrealized losses and fair values of investment securities, aggregated by investment category, and the length of time individual investment securities have been in a continuous unrealized loss position, as of March 31, 2016 and December 31, 2015 . Less than 12 Months 12 Months or More Total March 31, 2016 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Available-for-Sale: Obligations of U.S. government agencies $ 118,698 $ (226 ) $ 35,355 $ (98 ) $ 154,053 $ (324 ) U.S. agency residential mortgage-backed securities & collateralized mortgage obligations 146,840 (586 ) 25,708 (276 ) 172,548 (862 ) Private mortgage-backed securities — — 57 (2 ) 57 (2 ) Other investments — — — — — — Total $ 265,538 $ (812 ) $ 61,120 $ (376 ) $ 326,658 $ (1,188 ) Less than 12 Months 12 Months or More Total March 31, 2016 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Held-to-Maturity: State, county and municipal securities $ 3,379 $ (7 ) $ 3,606 $ (7 ) $ 6,985 $ (14 ) U.S. agency residential mortgage-backed securities & collateralized mortgage obligations 13,801 (4,364 ) 24,049 (781 ) 37,850 (5,145 ) Corporate securities 10,049 (61 ) — — 10,049 (61 ) Total $ 27,229 $ (4,432 ) $ 27,655 $ (788 ) $ 54,884 $ (5,220 ) Less than 12 Months 12 Months or More Total December 31, 2015 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Available-for-Sale: U.S. Treasury notes $ 2,092 $ (4 ) $ — $ — $ 2,092 $ (4 ) Obligations of U.S. government agencies 209,631 (1,077 ) 54,619 (533 ) 264,250 (1,610 ) U.S. agency residential mortgage-backed securities & collateralized mortgage obligations 343,875 (1,577 ) 28,010 (524 ) 371,885 (2,101 ) Private mortgage-backed securities — — 61 (1 ) 61 (1 ) Other investments 1,225 (9 ) — — 1,225 (9 ) Total $ 556,823 $ (2,667 ) $ 82,690 $ (1,058 ) $ 639,513 $ (3,725 ) Less than 12 Months 12 Months or More Total December 31, 2015 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Held-to-Maturity: State, county and municipal securities $ 10,182 $ (39 ) $ 9,476 $ (188 ) $ 19,658 $ (227 ) U.S. agency residential mortgage-backed securities & collateralized mortgage obligations 67,295 (4,288 ) 69,539 (1,132 ) 136,834 (5,420 ) Obligations of U.S. government agencies 19,738 (102 ) — — 19,738 (102 ) Corporate securities 31,135 (220 ) — — 31,135 (220 ) Total $ 128,350 $ (4,649 ) $ 79,015 $ (1,320 ) $ 207,365 $ (5,969 ) The investment portfolio is evaluated quarterly for other-than-temporary declines in the market value of each individual investment security. The Company had 109 and 198 individual investment securities that were in an unrealized loss position as of March 31, 2016 and December 31, 2015 , respectively. As of March 31, 2016 , the Company had the intent and ability to hold these investment securities for a period of time sufficient to allow for an anticipated recovery. Furthermore, the Company does not have the intent to sell any of the available-for-sale securities in the above table and it is more likely than not that the Company will not have to sell any securities before a recovery in cost. No impairment losses were recorded during three months ended March 31, 2016 and 2015 . Maturities of investment securities at March 31, 2016 are shown below. Maturities of mortgage-backed securities have been adjusted to reflect shorter maturities based upon estimated prepayments of principal. All other investment securities maturities are shown at contractual maturity dates. Available-for-Sale Held-to-Maturity March 31, 2016 Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair Value Within one year $ 317,502 $ 320,927 $ 87,930 $ 90,154 After one year but within five years 1,089,290 1,099,333 328,090 333,231 After five years but within ten years 70,534 71,242 125,412 128,977 After ten years 70,891 71,848 39,958 41,542 Total $ 1,548,217 $ 1,563,350 $ 581,390 $ 593,904 As of March 31, 2016 , the Company had investment securities callable within one year with amortized costs and estimated fair values of $ 277,491 and $ 277,837 , respectively, including callable structured notes with amortized costs and estimated fair values of $ 10,000 and $ 10,000 , respectively. These investment securities are primarily included in the after one year but within five years category in the table above.

Loans

Loans	3 Months Ended
	Mar. 31, 2016
Receivables [Abstract]
Loans	Loans The following table presents loans by class as of the dates indicated: March 31, December 31, Real estate loans: Commercial $ 1,764,492 $ 1,793,258 Construction: Land acquisition & development 219,450 224,066 Residential 113,317 111,763 Commercial 102,382 94,890 Total construction loans 435,149 430,719 Residential 1,021,443 1,032,851 Agricultural 153,054 156,234 Total real estate loans 3,374,138 3,413,062 Consumer: Indirect consumer 651,057 622,529 Other consumer 150,774 153,717 Credit card 63,624 68,107 Total consumer loans 865,455 844,353 Commercial 825,043 792,416 Agricultural 126,290 142,151 Other, including overdrafts 543 1,339 Loans held for investment 5,191,469 5,193,321 Mortgage loans held for sale 52,989 52,875 Total loans $ 5,244,458 $ 5,246,196 Loans from business combinations included in the table above include certain loans that had evidence of deterioration in credit quality since origination and for which it was probable, at acquisition, that all contractually required payments would not be collected. The following table displays the outstanding unpaid principal balance, accrued interest receivable and accrual status of loans acquired with credit impairment as of March 31, 2016 and 2015 : As of March 31, 2016 2015 Outstanding balance $ 33,175 $ 32,445 Carrying value Loans on accrual status 21,064 23,909 Loans on non-accrual status — — Total carrying value $ 21,064 $ 23,909 The following table summarizes changes in the accretable yield for loans acquired credit impaired for the three months ended March 31, 2016 and 2015 : Three Months Ended March 31, 2016 2015 Beginning balance $ 6,713 $ 5,781 Accretion income (614 ) (548 ) Reductions due to exit events (147 ) (396 ) Reclassifications from nonaccretable differences 726 2,143 Ending balance $ 6,678 $ 6,980 Loans are considered past due if the required principal and interest payments have not been received as of the date such payments were due. The following tables present the contractual aging of the Company’s recorded investment in past due loans by class as of the dates indicated: Total Loans 30 - 59 60 - 89 > 90 30 or More Days Days Days Days Current Non-accrual Total As of March 31, 2016 Past Due Past Due Past Due Past Due Loans Loans Loans Real estate Commercial $ 2,302 $ 2,975 $ 5 $ 5,282 $ 1,736,374 $ 22,836 $ 1,764,492 Construction: Land acquisition & development 951 351 857 2,159 210,994 6,297 219,450 Residential 96 — — 96 112,166 1,055 113,317 Commercial 184 — — 184 101,915 283 102,382 Total construction loans 1,231 351 857 2,439 425,075 7,635 435,149 Residential 4,804 985 1,750 7,539 1,010,803 3,101 1,021,443 Agricultural 27 — — 27 147,423 5,604 153,054 Total real estate loans 8,364 4,311 2,612 15,287 3,319,675 39,176 3,374,138 Consumer: Indirect consumer 4,448 1,075 188 5,711 644,517 829 651,057 Other consumer 613 226 38 877 149,419 478 150,774 Credit card 412 346 529 1,287 62,325 12 63,624 Total consumer loans 5,473 1,647 755 7,875 856,261 1,319 865,455 Commercial 2,144 763 232 3,139 799,325 22,579 825,043 Agricultural 1,972 322 451 2,745 122,782 763 126,290 Other, including overdrafts — 5 312 317 226 — 543 Loans held for investment 17,953 7,048 4,362 29,363 5,098,269 63,837 5,191,469 Mortgage loans originated for sale — — — — 52,989 — 52,989 Total loans $ 17,953 $ 7,048 $ 4,362 $ 29,363 $ 5,151,258 $ 63,837 $ 5,244,458 Total Loans 30 - 59 60 - 89 > 90 30 or More Days Days Days Days Current Non-accrual Total As of December 31, 2015 Past Due Past Due Past Due Past Due Loans Loans Loans Real estate Commercial $ 6,051 $ 724 $ 418 $ 7,193 $ 1,762,294 $ 23,771 $ 1,793,258 Construction: Land acquisition & development 3,190 163 1,325 4,678 212,757 6,631 224,066 Residential 1,288 — — 1,288 110,182 293 111,763 Commercial 3,232 — — 3,232 90,703 955 94,890 Total construction loans 7,710 163 1,325 9,198 413,642 7,879 430,719 Residential 5,991 1,196 2,063 9,250 1,018,359 5,242 1,032,851 Agricultural 176 17 — 193 150,686 5,355 156,234 Total real estate loans 19,928 2,100 3,806 25,834 3,344,981 42,247 3,413,062 Consumer: Indirect consumer 6,675 1,089 210 7,974 614,029 526 622,529 Other consumer 1,312 331 34 1,677 151,381 659 153,717 Credit card 533 317 477 1,327 66,768 12 68,107 Total consumer loans 8,520 1,737 721 10,978 832,178 1,197 844,353 Commercial 8,493 1,060 699 10,252 759,851 22,313 792,416 Agricultural 879 152 62 1,093 140,430 628 142,151 Other, including overdrafts — — 314 314 1,025 — 1,339 Loans held for investment 37,820 5,049 5,602 48,471 5,078,465 66,385 5,193,321 Mortgage loans originated for sale — — — — 52,875 — 52,875 Total loans $ 37,820 $ 5,049 $ 5,602 $ 48,471 $ 5,131,340 $ 66,385 $ 5,246,196 Acquired loans that met the criteria for nonaccrual of interest prior to acquisition were considered performing upon acquisition. If interest on non-accrual loans had been accrued, such income would have been approximately $ 790 and $ 832 for the three months ended March 31, 2016 and 2015 . The Company considers impaired loans to include all originated and acquired loans, except consumer loans, that are risk rated as doubtful, or have been placed on non-accrual status or renegotiated in troubled debt restructurings. The following tables present information on the Company’s recorded investment in impaired loans as of dates indicated: As of March 31, 2016 Unpaid Total Principal Balance Recorded Investment With No Allowance Recorded Investment With Allowance Total Recorded Investment Related Allowance Real estate: Commercial $ 55,222 $ 25,759 $ 18,117 $ 43,876 $ 4,526 Construction: Land acquisition & development 15,252 7,742 322 8,064 150 Residential 988 282 — 282 — Commercial 1,370 446 731 1,177 739 Total construction loans 17,610 8,470 1,053 9,523 889 Residential 5,664 3,019 1,152 4,171 160 Agricultural 6,685 5,816 201 6,017 7 Total real estate loans 85,181 43,064 20,523 63,587 5,582 Commercial 28,782 8,113 16,150 24,263 8,176 Agricultural 908 250 544 794 189 Total $ 114,871 $ 51,427 $ 37,217 $ 88,644 $ 13,947 As of December 31, 2015 Unpaid Total Principal Balance Recorded Investment With No Allowance Recorded Investment With Allowance Total Recorded Investment Related Allowance Real estate: Commercial $ 58,179 $ 27,882 $ 17,614 $ 45,496 $ 3,401 Construction: Land acquisition & development 15,503 7,245 778 8,023 282 Residential 992 293 — 293 — Commercial 1,264 340 739 1,079 739 Total construction loans 17,759 7,878 1,517 9,395 1,021 Residential 7,073 3,547 2,317 5,864 367 Agricultural 6,434 5,563 198 5,761 5 Total real estate loans 89,445 44,870 21,646 66,516 4,794 Commercial 29,593 10,744 13,727 24,471 6,487 Agricultural 1,349 622 356 978 294 Total $ 120,387 $ 56,236 $ 35,729 $ 91,965 $ 11,575 The following table presents the average recorded investment in and income recognized on impaired loans for the periods indicated: Three Months Ended March 31, 2016 2015 Average Recorded Investment Income Recognized Average Recorded Investment Income Recognized Real estate: Commercial $ 33,483 $ 36 $ 42,077 $ 150 Construction: Land acquisition & development 7,508 7 8,930 10 Residential 288 — 308 — Commercial 1,067 — 3,055 2 Total construction loans 8,863 7 12,293 12 Residential 4,206 1 3,127 1 Agricultural 5,748 1 8,655 22 Total real estate loans 52,300 45 66,152 185 Commercial 23,379 15 17,533 8 Agricultural 856 — 914 5 Total $ 76,535 $ 60 $ 84,599 $ 198 The amount of interest income recognized by the Company within the period that the loans were impaired was primarily related to loans modified in a troubled debt restructuring that remained on accrual status. Interest payments received on non-accrual impaired loans are applied to principal. Interest income is subsequently recognized only to the extent cash payments are received in excess of principal due. If interest on impaired loans had been accrued, interest income on impaired loans would have been approximately $ 929 and $ 1,035 for the three months ended March 31, 2016 and 2015 . Collateralized impaired loans are generally recorded at the fair value of the underlying collateral using discounted cash flows, independent appraisals and management estimates based upon current market conditions. For loans measured under the present value of cash flows method, the change in present value attributable to the passage of time, if applicable, is recognized in the provision for loan losses and thus no interest income is recognized. Modifications of performing loans are made in the ordinary course of business and are completed on a case-by-case basis as negotiated with the borrower. Loan modifications typically include interest rate concessions, interest only periods of less than twelve months, short-term payment deferrals and extension of amortization periods to provide payment relief. A loan modification is considered a troubled debt restructuring if the borrower is experiencing financial difficulties and the Company, for economic or legal reasons, grants a concession to the borrower that it would not otherwise consider. Certain troubled debt restructurings are on non-accrual status at the time of restructuring and are typically returned to accrual status after considering the borrower's sustained repayment performance in accordance with the restructuring agreement for a period of at least six months and management is reasonably assured of future performance. If the troubled debt restructuring meets these performance criteria and the interest rate granted at the modification is equal to or greater than the rate that the Company was willing to accept at the time of the restructuring for a new loan with comparable risk, then the loan will return to performing status and the accrual of interest will resume. The Company had loans renegotiated in troubled debt restructurings of $ 34,344 as of March 31, 2016 , of which $ 22,274 were included in non-accrual loans and $ 12,070 were on accrual status. The Company had loans renegotiated in troubled debt restructurings of $ 40,330 as of December 31, 2015 , of which $ 24,911 were included in non-accrual loans and $ 15,419 were on accrual status. The following table presents information on the Company's troubled debt restructurings that occurred during the three months ended March 31, 2016 . Number of Notes Type of Concession Principal Balance at Restructure Date Three Months Ended March 31, 2016 Interest only period Extension of terms or maturity Commercial Real Estate 3 $ 576 $ 204 $ 780 Total loans restructured during period 3 $ 576 $ 204 $ 780 For troubled debt restructurings that were on non-accrual status or otherwise deemed impaired before the modification, a specific reserve may already be recorded. In periods subsequent to modification, the Company continues to evaluate all troubled debt restructurings for possible impairment and recognizes impairment through the allowance. Additionally these loans continue to work their way through the credit cycle through charge-off, pay-off or foreclosure. Financial effects of modifications of troubled debt restructurings may include principal loan forgiveness or other charge-offs directly related to the restructuring. The Company had no charge-offs directly related to modifying troubled debt restructurings during the three months ended March 31, 2016 or 2015 . The following table presents information on the Company's troubled debt restructurings during the previous 12 months for which there was a payment default during the three months ended March 31, 2016 . The Company considers a payment default to occur on troubled debt restructurings when the loan is 90 days or more past due or was placed on non-accrual status after the modification. Three Months Ended March 31, 2016 Number of Notes Balance Commercial Real Estate 1 $ 203 Total 1 $ 203 At March 31, 2016 , there were no material commitments to lend additional funds to borrowers whose existing loans have been renegotiated or are classified as non-accrual. As part of the on-going and continuous monitoring of the credit quality of the Company’s loan portfolio, management tracks internally assigned risk classifications of loans. The Company adheres to a Uniform Classification System developed jointly by the various bank regulatory agencies to internally risk rate loans. The Uniform Classification System defines three broad categories of criticized assets, which the Company uses as credit quality indicators: Other Assets Especially Mentioned — includes loans that exhibit weaknesses in financial condition, loan structure or documentation, which if not promptly corrected, may lead to the development of abnormal risk elements. Substandard — includes loans that are inadequately protected by the current sound worth and paying capacity of the borrower. Although the primary source of repayment for a substandard loan is not currently sufficient, collateral or other sources of repayment are sufficient to satisfy the debt. Continuance of a substandard loan is not warranted unless positive steps are taken to improve the worthiness of the credit. Doubtful — includes loans that exhibit pronounced weaknesses to a point where collection or liquidation in full, on the basis of currently existing facts, conditions and values, is highly questionable and improbable. Doubtful loans are required to be placed on non-accrual status and are assigned specific loss exposure. Company management undertakes the same process for assigning risk ratings to acquired loans as it does for originated loans. Acquired loans rated as substandard or lower or that were on non-accrual status or designated as troubled debt restructurings at the time of acquisition are deemed to be acquired credit impaired loans accounted for under ASC Topic 310-30, regardless of whether they are classified as performing or non-performing loans. The following tables present the Company’s recorded investment in criticized loans by class and credit quality indicator based on the most recent analysis performed as of the dates indicated: As of March 31, 2016 Other Assets Especially Mentioned Substandard Doubtful Total Criticized Loans Real estate: Commercial $ 77,147 $ 82,536 $ 14,311 $ 173,994 Construction: Land acquisition & development 11,854 11,226 1,515 24,595 Residential 2,003 389 — 2,392 Commercial 4,056 429 748 5,233 Total construction loans 17,913 12,044 2,263 32,220 Residential 5,681 10,107 477 16,265 Agricultural 7,519 18,920 — 26,439 Total real estate loans 108,260 123,607 17,051 248,918 Consumer: Indirect consumer 704 1,446 144 2,294 Other consumer 1,024 914 211 2,149 Total consumer loans 1,728 2,360 355 4,443 Commercial 31,392 34,039 16,629 82,060 Agricultural 3,613 7,820 543 11,976 Total $ 144,993 $ 167,826 $ 34,578 $ 347,397 As of December 31, 2015 Other Assets Especially Mentioned Substandard Doubtful Total Criticized Loans Real estate: Commercial $ 61,787 $ 84,556 $ 10,609 $ 156,952 Construction: Land acquisition & development 16,593 12,482 591 29,666 Residential 1,640 1,886 — 3,526 Commercial 166 323 756 1,245 Total construction loans 18,399 14,691 1,347 34,437 Residential 4,453 9,661 2,540 16,654 Agricultural 6,114 16,529 — 22,643 Total real estate loans 90,753 125,437 14,496 230,686 Consumer: Indirect consumer 644 1,131 154 1,929 Other consumer 651 1,130 198 1,979 Total consumer loans 1,295 2,261 352 3,908 Commercial 32,975 27,982 15,085 76,042 Agricultural 2,247 7,105 417 9,769 Total $ 127,270 $ 162,785 $ 30,350 $ 320,405 The Company maintains a credit review function, which is independent of the credit approval process, to assess assigned internal risk classifications and monitor compliance with internal lending policies and procedures. Written action plans with firm target dates for resolution of identified problems are maintained and reviewed on a quarterly basis for all categories of criticized loans.

Allowance For Loan Losses

Allowance For Loan Losses	3 Months Ended
	Mar. 31, 2016
Receivables [Abstract]
Allowance For Loan Losses	The following tables present a summary of changes in the allowance for loan losses by portfolio segment for the periods indicated. Three Months Ended March 31, 2016 Real Estate Consumer Commercial Agriculture Other Total Allowance for loan losses: Beginning balance $ 52,296 $ 5,144 $ 18,775 $ 602 $ — $ 76,817 Provision charged to operating expense (16,081 ) 1,229 17,690 1,162 — 4,000 Less loans charged-off (1,922 ) (1,892 ) (488 ) — — (4,302 ) Add back recoveries of loans previously charged-off 2,359 775 275 — — 3,409 Ending balance $ 36,652 $ 5,256 $ 36,252 $ 1,764 $ — $ 79,924 As of March 31, 2016 Real Estate Consumer Commercial Agriculture Other Total Allowance for loan losses: Loans individually evaluated for impairment $ 5,582 $ — $ 8,176 $ 189 $ — $ 13,947 Loans collectively evaluated for impairment 31,070 5,256 28,076 1,575 — 65,977 Allowance for loan losses $ 36,652 $ 5,256 $ 36,252 $ 1,764 $ — $ 79,924 Individually evaluated for impairment $ 63,587 $ — $ 24,263 $ 794 $ — $ 88,644 Collectively evaluated for impairment 3,310,551 865,455 800,780 125,496 543 5,102,825 Total loans $ 3,374,138 $ 865,455 $ 825,043 $ 126,290 $ 543 $ 5,191,469 Three Months Ended March 31, 2015 Real Estate Consumer Commercial Agriculture Other Total Allowance for loan losses: Beginning balance $ 53,884 $ 5,035 $ 14,307 $ 974 $ — $ 74,200 Provision charged to operating expense (1,031 ) 1,125 993 8 — 1,095 Less loans charged-off (186 ) (1,301 ) (374 ) — — (1,861 ) Add back recoveries of loans previously charged-off 992 640 270 — — 1,902 Ending balance $ 53,659 $ 5,499 $ 15,196 $ 982 $ — $ 75,336 As of December 31, 2015 Real Estate Consumer Commercial Agriculture Other Total Allowance for loan losses: Loans individually evaluated for impairment $ 4,794 $ — $ 6,487 $ 294 $ — $ 11,575 Loans collectively evaluated for impairment 47,502 5,144 12,288 308 — 65,242 Allowance for loan losses $ 52,296 $ 5,144 $ 18,775 $ 602 $ — $ 76,817 Total loans: Individually evaluated for impairment $ 66,516 $ — $ 24,471 $ 978 $ — $ 91,965 Collectively evaluated for impairment 3,346,546 844,353 767,945 141,173 1,339 5,101,356 Total loans $ 3,413,062 $ 844,353 $ 792,416 $ 142,151 $ 1,339 $ 5,193,321 The Company performs a quarterly assessment of the adequacy of its allowance for loan losses in accordance with generally accepted accounting principles. The methodology used to assess the adequacy is consistently applied to the Company's loan portfolio and consists of three elements: (1) specific valuation allowances based on probable losses on impaired loans; (2) historical valuation allowances based on loan loss experience for similar loans with similar characteristics and trends; and (3) general valuation allowances determined based on changes in the nature of the loan portfolio, overall portfolio quality, industry concentrations, delinquency trends, general economic conditions and other qualitative risk factors both internal and external to the Company. Specific allowances are established for loans where management has determined that probability of a loss exists by analyzing the borrower’s ability to repay amounts owed, collateral deficiencies and any relevant qualitative or economic factors impacting the loan. Historical valuation allowances are determined by applying percentage loss factors to the credit exposures from outstanding loans. For commercial, agricultural and real estate loans, loss factors are applied based on the internal risk classifications of these loans. For consumer loans, loss factors are applied on a portfolio basis. For commercial, agriculture and real estate loans, loss factor percentages are based on a migration analysis of our historical loss experience, designed to account for credit deterioration. For consumer loans, loss factor percentages are based on a one-year loss history. General valuation allowances are determined by evaluating, on a quarterly basis, changes in the nature and volume of the loan portfolio, overall portfolio quality, industry concentrations, current economic and regulatory conditions and the estimated impact of these factors on historical loss rates. An allowance for loan losses is established for loans acquired credit impaired and for which the Company projects a decrease in the expected cash flows in periods subsequent to the acquisition of such loans. As of March 31, 2016 and December 31, 2015 , the Company's allowance for loan losses included $393 and $287 , respectively, related to loans acquired credit impaired.

OREO

OREO	3 Months Ended
	Mar. 31, 2016
Repossessed Assets [Abstract]
Other Real Estate Owned	Other Real Estate Owned Information with respect to the Company's other real estate owned follows: Three Months Ended March 31, 2016 2015 Beginning balance $ 6,254 $ 13,554 Additions 3,227 3,257 Valuation adjustments (17 ) (106 ) Dispositions (207 ) (1,571 ) Ending balance $ 9,257 $ 15,134 Foreclosed residential real estate properties of $ 4,087 and $1,686 were included in other real estate owned as of March 31, 2016 and December 31, 2015, respectively. The Company did not have any consumer mortgage loans collateralized by residential real estate property that were in the process of foreclosure as of March 31, 2016 or December 31, 2015.

Derivatives and Hedging

Derivatives and Hedging	3 Months Ended
	Mar. 31, 2016
Derivative [Line Items]
Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block]	March 31, 2016 December 31, 2015 Notional Amount Estimated Fair Value Notional Amount Estimated Fair Value Derivative Assets (included in other assets on balance sheet): Derivatives designated as hedges: Interest rate swap contracts $ — $ — $ 100,000 $ 165 Non-hedging interest rate derivatives: Interest rate swap contracts 9,281 1,102 9,369 788 Interest rate lock commitments 112,705 1,036 — — Total derivative assets $ 121,986 $ 2,138 $ 109,369 $ 953 Derivative Liabilities (included in accounts payable and accrued expenses on balance sheet): Derivatives designated as hedges: Interest rate swap contracts $ 100,000 $ 2,032 $ — $ — Non-hedging interest rate derivatives: Interest rate swap contracts 9,281 1,173 9,369 829 Forward loan sales contracts 77,329 414 — — Total derivative liabilities $ 186,610 $ 3,619 $ 9,369 $ 829
Derivative Instruments and Hedging Activities Disclosure [Text Block]	Derivatives and Hedging Activities Interest Rate Swap Contracts Designated as Hedges. For asset and liability management purposes, the Company has entered into interest rate swap contracts to hedge against changes in forecasted cash flows due to interest rate exposures. The swap agreements are derivative instruments and convert a portion of the Company’s forecasted variable rate debt to a fixed rate (i.e., cash flow hedge) over the payment term of the interest rate swap. The effective portion of the gain or loss on cash flow hedging instruments is initially reported as a component of other comprehensive income and subsequently reclassified into earnings in the same period during which the transaction affects earnings. The ineffective portion of the gain or loss on derivative instruments, if any, is recognized in earnings. The Company does not enter into interest rate swap agreements for trading or speculative purposes. On September 22, 2015 , the Company entered into an interest rate swap contract with a notional amount of $100,000 that was designated as a cash flow hedge. Under the terms of the interest rate swap contract, the Company pays a fixed interest rate of 1.94% and the counterparty pays to the Company a variable interest rate equal to the three-month LIBOR. No cash is exchanged until the effective date, which begins on September 15, 2017 and ends on September 15, 2020 . The Company designated the interest payments related to Federal Home Loan Bank borrowings as the cash flow hedge. The hedge was fully effective during the current period. As such, no amount of ineffectiveness was included in the Company's income statement for the three months ended March 31, 2016. The Company expects the hedge to remain highly effective during the remaining term of the interest rate swap. Non-Hedging Interest Rate Swap Contracts. The Company enters into certain interest rate swap contracts that are not designated as hedging instruments. These derivative contracts relate to transactions in which the Company enters into an interest rate swap with a customer while at the same time entering into an offsetting interest rate swap with a third party financial institution. Because the Company acts as an intermediary for the customer, changes in the fair value of the underlying derivative contracts for the most part offset each other and do not significantly impact the Company's results of operations. Interest Rate Lock Commitments and Forward Loan Sales Contracts. In the normal course of business, the Company enters into interest rate lock commitments to finance residential mortgage loans that are not designated as accounting hedges. These commitments, which contain fixed expiration dates, offer the borrower an interest rate guarantee provided the loan meets underwriting guidelines and closes within the timeframe established by the Company. Interest rate risk arises on these commitments and subsequently closed loans if interest rates change between the time of the interest rate lock and the delivery of the loan to the investor. Loan commitments related to residential mortgage loans intended to be sold are considered derivatives and are marked to market through earnings. In addition to the effects of the change in market interest rate, the fair value measurement of the derivative also contemplates the expected cash flows to be received from the counterparty to the future sale of the loan. The Company sells residential mortgage loans on either a best efforts or mandatory delivery basis. The Company mitigates the effect of the interest rate risk inherent in providing interest rate lock commitments by entering into a forward loan sales contract. During the interest rate lock commitment period, these forward loan sales contracts are marked to market through earnings and are not designated as accounting hedges. Exclusive of the fair value component associated with the projected cash flows from the loan delivery to the investor, the changes in fair value related to movements in market rates of the interest rate lock commitments and the forward loan sales contracts generally move in opposite directions, and the net impact of changes in these valuations on net income during the loan commitment period is generally inconsequential. When the loan is funded to the borrower, the interest rate lock commitment derivative expires and the Company records a loan held for sale. The forward loan sales contract acts as a hedge against the variability in cash to be received from the loan sale. The changes in measurement of the estimated fair values of the interest rate lock commitments and forward loan sales contracts are included in mortgage banking revenues in the accompanying consolidated statements of income. The notional amounts and estimated fair values of the Company's derivatives are presented in the following table. Fair value estimates are obtained from third parties and are based on pricing models. March 31, 2016 December 31, 2015 Notional Amount Estimated Fair Value Notional Amount Estimated Fair Value Derivative Assets (included in other assets on balance sheet): Derivatives designated as hedges: Interest rate swap contracts $ — $ — $ 100,000 $ 165 Non-hedging interest rate derivatives: Interest rate swap contracts 9,281 1,102 9,369 788 Interest rate lock commitments 112,705 1,036 — — Total derivative assets $ 121,986 $ 2,138 $ 109,369 $ 953 Derivative Liabilities (included in accounts payable and accrued expenses on balance sheet): Derivatives designated as hedges: Interest rate swap contracts $ 100,000 $ 2,032 $ — $ — Non-hedging interest rate derivatives: Interest rate swap contracts 9,281 1,173 9,369 829 Forward loan sales contracts 77,329 414 — — Total derivative liabilities $ 186,610 $ 3,619 $ 9,369 $ 829 The following table presents the pre-tax gains or losses related to derivative contracts that were recorded in accumulated other comprehensive income and other non-interest income in the Company's statements of income for the periods indicated: Three months ended March 31, 2016 March 31, 2015 Derivatives designated as hedges: Amount of loss recognized in other comprehensive income (effective portion) $ (2,197 ) $ — Non-hedging interest rate derivatives: Amount of loss recognized in other non-interest income (29 ) (7 ) Amount of gains recognized in mortgage banking revenues 695 —

Capital Stock

Capital Stock	3 Months Ended
	Mar. 31, 2016
Equity [Abstract]
Common Stock	Capital Stock The Company had 21,007,483 shares of Class A common stock and 23,700,002 shares of Class B common stock outstanding as of March 31, 2016 . The Company had 21,698,594 shares of Class A common stock and 23,729,631 shares of Class B common stock outstanding as of December 31, 2015 . During the three months ended March 31, 2016 , the Company repurchased and retired 948,242 shares of its Class A common stock in open market transactions at an aggregate purchase price of $ 24,792 . During the three months ended March 31, 2015 , the Company repurchased and retired 565,875 shares of its Class A common stock in a privately negotiated transaction at an aggregate purchase price of $14,674 . The repurchases were made pursuant to stock repurchase programs approved by the Company's Board of Directors. Under the terms of the current stock repurchase program, the Company may repurchase up to an additional 51,758 shares of its Class A common stock. All other stock repurchases during the three months ended March 31, 2016 and 2015 were redemptions of vested restricted shares tendered in lieu of cash for payment of income tax withholding amounts by participants of the Company's equity compensation plans.

Earnings per Common Share

Earnings per Common Share	3 Months Ended
	Mar. 31, 2016
Earnings Per Share [Abstract]
Earnings per Common Share	Earnings per Common Share Basic earnings per common share is calculated by dividing net income by the weighted average number of common shares outstanding during the period presented, excluding unvested restricted stock. Diluted earnings per share is calculated by dividing net income by the weighted average number of common shares determined for the basic earnings per share computation plus the dilutive effects of stock-based compensation using the treasury stock method. The following table sets forth the computation of basic and diluted earnings per share for the three month periods ended March 31, 2016 and 2015 . Three Months Ended March 31, 2016 2015 Net income $ 20,124 $ 20,980 Weighted average common shares outstanding for basic earnings per share computation 44,719,218 45,378,230 Dilutive effects of stock-based compensation 394,834 461,961 Weighted average common shares outstanding for diluted earnings per common share computation 45,114,052 45,840,191 Basic earnings per common share $ 0.45 $ 0.46 Diluted earnings per common share $ 0.45 $ 0.46 The Company had 226,821 and 166,770 shares of unvested restricted stock as of March 31, 2016 and 2015 , respectively, that were not included in the computation of diluted earnings per common share because performance conditions for vesting had not been met. In addition, the Company had 40,865 and 5,000 shares of unvested time restricted stock and stock options outstanding as of March 31, 2016 and as of March 31, 2015 , respectively, that were not included in the computation of diluted earnings per common shares because their effect would be anti-dilutive.

Regulatory Capital

Regulatory Capital	3 Months Ended
	Mar. 31, 2016
Banking and Thrift [Abstract]
Regulatory Capital	Regulatory Capital On July 2, 2013, the Board of Governors of the Federal Reserve Bank issued a final rule implementing a revised regulatory capital framework for U.S. banks in accordance with the Basel III international accord, ("Basel III"). Basel III includes a more stringent definition of capital and introduces a new common equity tier 1, or CET1, capital requirement, sets forth a comprehensive methodology for calculating risk-weighted assets, introduces a conservation buffer and sets out minimum capital ratios and overall capital adequacy standards. Under Basel III, certain deductions and adjustments to regulatory capital began to phase in starting January 1, 2015 and will be fully implemented on January 1, 2018. The capital conservation buffer required under Basel III began to phase in starting January 1, 2016 and will be fully implemented on January 1, 2019. As of March 31, 2016 and December 31, 2015 , the Company exceeded all capital adequacy requirements to which it is subject. Actual capital amounts and ratios for the Company and its bank subsidiary, as of March 31, 2016 and December 31, 2015 are presented in the following tables: Actual Adequately Capitalized Basel III Phase-In Schedule Adequately Capitalized Basel III Fully Phased-In Well Capitalized (1) Amount Ratio Amount Ratio Amount Ratio Amount Ratio March 31, 2016 Total risk-based capital: Consolidated $ 930,048 15.0 % $ 533,419 8.6 % $ 649,379 10.5 % $ 618,456 10.0 % FIB 876,265 14.2 531,493 8.6 647,035 10.5 616,224 10.0 Tier 1 risk-based capital: Consolidated 848,709 13.7 409,727 6.6 525,688 8.5 494,765 8.0 FIB 799,201 13.0 408,248 6.6 523,790 8.5 492,979 8.0 Common equity tier 1 risk-based capital: Consolidated 768,709 12.4 316,959 5.1 432,919 7.0 401,997 6.5 FIB 799,201 13.0 315,815 5.1 431,357 7.0 400,546 6.5 Leverage capital ratio: Consolidated 848,709 10.1 337,137 4.0 337,137 4.0 421,421 5.0 FIB 799,201 9.5 336,258 4.0 336,258 4.0 420,322 5.0 Actual Adequately Capitalized Basel III Phase-In Schedule Adequately Capitalized Basel III Fully Phased-In Well Capitalized (1) Amount Ratio Amount Ratio Amount Ratio Amount Ratio December 31, 2015 Total risk-based capital: Consolidated $ 946,156 15.4 % $ 492,692 8.0 % $ 646,658 10.5 % $ 615,865 10.0 % FIB 882,504 14.4 490,866 8.0 644,262 10.5 613,582 10.0 Tier 1 risk-based capital: Consolidated 861,339 14.0 369,519 6.0 523,485 8.5 $ 492,692 8.0 FIB 805,805 13.1 368,149 6.0 521,545 8.5 490,866 8.0 Common equity tier 1 risk-based capital: Consolidated 781,339 12.7 277,139 4.5 431,105 7.0 $ 400,312 6.5 FIB 805,805 13.1 276,112 4.5 429,508 7.0 398,829 6.5 Leverage capital ratio: Consolidated 861,339 10.1 340,480 4.0 340,480 4.0 $ 425,600 5.0 FIB 805,805 9.5 339,316 4.0 339,316 4.0 424,145 5.0 (1) The ratios for the well capitalized requirement are only applicable to FIB. However, the Company manages its capital position as if the requirement applies to the consolidated entity and has presented the ratios as if they also applied on a consolidated basis.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies In the normal course of business, the Company is involved in various other claims and litigation. In the opinion of management, following consultation with legal counsel, the ultimate liability or disposition thereof of all other claims and litigation is not expected to have a material adverse effect on the consolidated financial condition, results of operations or liquidity of the Company. As of March 31, 2016 , the Company had a commitment under a forward starting interest rate swap contract with a notional amount of $ 100,000 . For additional information about the forward starting interest rate swap contract, see Note 7 — Derivatives and Hedging Activity. Residential mortgage loans sold to investors in the secondary market are sold with varying recourse provisions. Essentially all of the loan sales agreements require the repurchase of a mortgage loan by the seller in situations such as breach of representation, warranty or covenant; untimely document delivery; false or misleading statements; failure to obtain certain certificates or insurance; unmarketability; etc. Certain loan sales agreements contain repurchase requirements based on payment-related defects that are defined in terms of the number of days or months since the purchase, the sequence number of the payment, and/or the number of days of payment delinquency. Based on the specific terms stated in the agreements, the Company had $ 3,465 of sold residential mortgage loans with recourse provisions still in effect as of March 31, 2016 .

Financial Instruments with Off-

Financial Instruments with Off-Balance Sheet Risk	3 Months Ended
	Mar. 31, 2016
Financial Instruments with Off-Balance Sheet Risk [Abstract]
Financial Instruments with Off-Balance Sheet Risk	Financial Instruments with Off-Balance Sheet Risk The Company is a party to financial instruments with off-balance sheet risk in the normal course of business to meet the financing needs of its customers. These financial instruments include commitments to extend credit and standby letters of credit. Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established in the commitment contract. Since many of the commitments are expected to expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. At March 31, 2016 , commitments to extend credit to existing and new borrowers approximated $ 1,582,107 , which included $ 562,367 on unused credit card lines and $ 400,922 with commitment maturities beyond one year. Standby letters of credit are conditional commitments issued by the Company to guarantee the performance of a customer to a third party. At March 31, 2016 , the Company had outstanding standby letters of credit of $ 52,402 . The estimated fair value of the obligation undertaken by the Company in issuing the standby letters of credit is included in other liabilities in the Company’s consolidated balance sheet.

Other Comprehensive Income

Other Comprehensive Income	3 Months Ended
	Mar. 31, 2016
Equity [Abstract]
Other Comprehensive Income	Other Comprehensive Income/Loss The gross amounts of each component of other comprehensive income and the related tax effects are as follows: Pre-tax Tax Expense (Benefit) Net of Tax Three Months Ended March 31, 2016 2015 2016 2015 2016 2015 Investment securities available-for sale: Change in net unrealized gains during period $ 8,613 $ 10,608 $ 3,360 $ 4,174 $ 5,253 $ 6,434 Reclassification adjustment for net (gains) losses included in net income 21 (6 ) 8 (2 ) 13 (4 ) Change in unamortized loss on available- for-sale securities transferred into held-to- maturity 465 451 183 177 282 274 Unrealized loss on derivatives (2,197 ) — (835 ) — (1,362 ) — Defined benefits post-retirement benefit plan: Change in net actuarial loss 15 15 6 6 9 9 Total other comprehensive income (loss) $ 6,917 $ 11,068 $ 2,722 $ 4,355 $ 4,195 $ 6,713 The components of accumulated other comprehensive income, net of related tax effects, are as follows: March 31, December 31, Net unrealized gain on investment securities available-for-sale $ 6,232 $ 684 Net unrealized gain (loss) on derivatives (1,262 ) 100 Net actuarial loss on defined benefit post-retirement benefit plans (369 ) (378 ) Net accumulated other comprehensive income $ 4,601 $ 406

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. There is a fair value hierarchy which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The three levels of inputs that may be used to measure fair value are as follows: • Level 1 - Quoted prices in active markets for identical assets or liabilities • Level 2 - Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities • Level 3 - Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of of assets or liabilities The methodologies used by the Company in determining the fair values of each class of financial instruments are based primarily on the use of independent, market-based data to reflect a value that would be reasonably expected in an orderly transaction between market participants at the measurement date, and therefore as classified within Level 2 of the valuation hierarchy. There were no transfers between fair value hierarchy levels during the three months ended March 31, 2016 and 2015. Further details on the methods used to estimate the fair value of each class of financial instruments above are discussed below: Investment Securities Available-for-Sale . The Company obtains fair value measurements for investment securities from an independent pricing service. The fair value measurements consider observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information and the investment's terms and conditions, among other things. Vendors chosen by the Company are widely recognized vendors whose evaluations support the pricing functions of financial institutions, investment and mutual funds, and portfolio managers. If needed, a broker may be utilized to determine the reported fair value of investment securities . Loans Held for Sale. Fair value measurements for loans held for sale are obtained from an independent pricing service. The fair value measurements consider observable data that may include binding contracts or quotes or bids from third party investors. Interest Rate Swap Contracts. Fair values for derivative interest rate swap contracts are based upon the estimated amounts to settle the contracts considering current interest rates and are calculated using discounted cash flows that are observable or that can be corroborated by observable market data. The inputs used to determine fair value include the 3 month LIBOR forward curve to estimate variable rate cash inflows and the fed funds effective swap rate to estimate the discount rate. The estimated variable rate cash inflows are compared to the fixed rate outflows and such difference is discounted to a present value to estimate the fair value of the interest rate swaps. The change in the value of derivative assets attributable to basis risk, or the risk that offsetting investments in a hedging strategy will not experience price changes in entirely opposite directions from each other, was not significant in the reported periods. The Company also obtains and compares the reasonableness of the pricing from an independent third party. Interest Rate Lock Commitments. Fair value measurements for interest rate lock commitments are obtained from an independent pricing service. The fair value measurements consider observable data that may include prices available from secondary market investors taking into consideration various characteristics of the loan, including the loan amount, interest rate, value of the servicing and loan to value ratio, among other things, adjusted to reflect changes in interest rates, the estimated pull-through rate and estimated direct costs necessary to complete the commitment into a closed loan. Forward Loan Sales Contracts. The fair value measurements for forward loan sales contracts are obtained from an independent pricing service. The fair value measurements consider observable data that includes sales of similar loans and mortgage-backed securities that are traded publicly in active exchange markets. Deferred Compensation Plan Assets and Liabilities. The fair values of deferred compensation plan assets are based primarily on the use of independent, market-based data to reflect a value that would be reasonably expected in an orderly transaction between market participants at the measurement date. These investments are in the same funds and purchased in the same amounts as the participants’ selected investments, which represent the underlying liabilities to plan participants. Deferred compensation plan liabilities are recorded at amounts due to participants, based on the fair value of participants’ selected investments. Financial assets and financial liabilities measured at fair value on a recurring basis are as follows: Fair Value Measurements at Reporting Date Using As of March 31, 2016 Balance Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Investment securities available-for-sale: U.S. Treasury Notes $ 3,935 $ — $ 3,935 $ — Obligations of U.S. government agencies 531,432 — 531,432 — U.S. agencies mortgage-backed securities & collateralized mortgage obligations 1,024,363 — 1,024,363 — Private mortgage-backed securities 143 — 143 — Other investments 3,477 — 3,477 — Loans held for sale 52,989 — 52,989 — Derivative assets: Interest rate swap contracts 1,102 — 1,102 — Interest rate lock commitments 1,036 — 1,036 — Derivative liabilities: Interest rate swap contracts 3,205 — 3,205 — Forward loan sale contracts 414 — 414 — Deferred compensation plan assets 9,566 — 9,566 — Deferred compensation plan liabilities 9,566 — 9,566 — Fair Value Measurements at Reporting Date Using As of December 31, 2015 Balance Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Investment securities available-for-sale: U.S. Treasury notes $ 3,911 $ — $ 3,911 $ — Obligations of U.S. government agencies 520,181 — 520,181 — U.S. agencies mortgage-backed securities & collateralized mortgage obligations 929,046 — 929,046 — Private mortgage-backed securities 156 — 156 — Other investments 3,546 — 3,546 — Derivative assets: Interest rate swap contracts 953 — 953 — Derivative liabilities Interest rate swap contracts 829 — 829 — Deferred compensation plan assets 10,149 — 10,149 — Deferred compensation plan liabilities 10,149 — 10,149 — Additionally, from time to time, certain assets are measured at fair value on a non-recurring basis. Adjustments to fair value generally result from the application of lower-of-cost-or-market accounting or write-downs of individual assets due to impairment. The following table presents information about the Company’s assets and liabilities measured at fair value on a non-recurring basis. Fair Value Measurements at Reporting Date Using As of March 31, 2016 Balance Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Impaired loans $ 19,363 $ — $ — $ 19,363 Other real estate owned 3,464 — — 3,464 Long-lived assets to be disposed of by sale 1,506 — — 1,506 Fair Value Measurements at Reporting Date Using As of December 31, 2015 Balance Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Impaired loans $ 20,875 $ — $ — $ 20,875 Other real estate owned 1,789 — — 1,789 Long-lived assets to be disposed of by sale 1,506 — — 1,506 Impaired Loans. Collateralized impaired loans are reported at the fair value of the underlying collateral if repayment is expected solely from collateral. The impaired loans are reported at fair value through specific valuation allowance allocations. In addition, when it is determined that the fair value of an impaired loan is less than the recorded investment in the loan, the carrying value of the loan is adjusted to fair value through a charge to the allowance for loan losses. Collateral values are estimated using independent appraisals and management estimates of current market conditions. As of March 31, 2016 , certain impaired loans with a carrying value of $ 42,700 were reduced by specific valuation allowance allocations of $ 13,946 and partial loan charge-offs of $ 9,391 resulting in a reported fair value of $ 19,363 . As of December 31, 2015 , certain impaired loans with a carrying value of $ 42,679 were reduced by specific valuation allowance allocations of $ 11,575 and partial loan charge-offs of $ 10,229 resulting in a reported fair value of $ 20,875 . OREO. The fair values of OREO are estimated using independent appraisals and management estimates of current market conditions. Upon initial recognition, write-downs based on the foreclosed asset's fair value at foreclosure are reported through charges to the allowance for loan losses. Periodically, the fair value of foreclosed assets is remeasured with any subsequent write-downs charged to OREO expense in the period in which they are identified. Write-downs of $17 during the three months ended March 31, 2016 included $11 directly related to receipt of updated appraisals and $ 6 based on management estimates of the current fair value of properties. Write downs of $106 during the three months ended March 31, 2015 were based on management's estimate of the current fair value of the properties. Long-lived Assets to be Disposed of by Sale. Long-lived assets to be disposed of by sale are carried at the lower of carrying value or fair value less estimated costs to sell. The fair values of long-lived assets to be disposed of by sale are based upon observable market data and management estimates of current market conditions. As of March 31, 2016 and December 31, 2015 , the Company had long-lived assets to be disposed of by sale with carrying values aggregating $2,363 that were reduced by write-downs of $857 resulting in an aggregate fair value of $1,506 . The following table presents additional quantitative information about assets measured at fair value on a non-recurring basis and for which the Company has utilized Level 3 inputs to determine fair values: Fair Value As of March 31, 2016 December 31, 2015 Valuation Technique Unobservable Inputs Range (Weighted Average) Impaired loans $ 19,363 $ 20,875 Appraisal Appraisal adjustment 0% - 53% (38%) Other real estate owned 3,464 1,789 Appraisal Appraisal adjustment 2% - 96% (19%) Long-lived assets to be disposed of by sale 1,506 1,506 Appraisal Appraisal adjustment 0% - 9% (6%) The Company is required to disclose the fair value of financial instruments for which it is practical to estimate fair value. The methodologies for estimating the fair value of financial instruments that are measured at fair value on a recurring or non-recurring basis are discussed above. The methodologies for estimating the fair value of other financial instruments are discussed below. For financial instruments bearing a variable interest rate where no credit risk exists, it is presumed that recorded book values are reasonable estimates of fair value. Financial Assets. Carrying values of cash, cash equivalents and accrued interest receivable approximate fair values due to the liquid and/or short-term nature of these instruments. Fair values for investment securities held-to-maturity are obtained from an independent pricing service, which considers observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information and the investment’s terms and conditions, among other things. Fair values of fixed rate loans and variable rate loans that reprice on an infrequent basis are estimated by discounting future cash flows using current interest rates at which similar loans with similar terms would be made to borrowers of similar credit quality. Carrying values of variable rate loans that reprice frequently, and with no change in credit risk, approximate the fair values of these instruments. Financial Liabilities. The fair values of demand deposits, savings accounts, securities sold under repurchase agreements and accrued interest payable are the amounts payable on demand at the reporting date. The fair values of fixed-maturity certificates of deposit are estimated using external market rates currently offered for deposits with similar remaining maturities. The fair values of derivative liabilities are obtained from an independent pricing service, which considers observable data that may include the three-month LIBOR forward curve, the federal funds effective swap rate and cash flows, among other things. The carrying values of the interest bearing demand notes to the United States Treasury are deemed an approximation of fair values due to the frequent repayment and repricing at market rates. The fixed and floating rate subordinated debentures, floating rate subordinated term loan, notes payable to the FHLB, fixed rate subordinated term debt, and capital lease obligation are estimated by discounting future cash flows using current rates for advances with similar characteristics. Commitments to Extend Credit and Standby Letters of Credit. The fair value of commitments to extend credit and standby letters of credit, based on fees currently charged to enter into similar agreements, is not significant. The estimated fair values of financial instruments that are reported in the Company's consolidated balance sheets, segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value, are as follows: Fair Value Measurements at Reporting Date Using As of March 31, 2016 Carrying Amount Estimated Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial assets: Cash and cash equivalents $ 655,528 $ 655,528 $ 655,528 $ — $ — Investment securities available-for-sale 1,563,350 1,563,350 — 1,563,350 — Investment securities held-to-maturity 581,390 593,904 — 593,904 — Accrued interest receivable 26,907 26,907 — 26,907 — Mortgage servicing rights, net 15,574 26,359 — 26,359 — Net loans 5,164,534 5,105,350 — 5,085,987 19,363 Derivative assets 2,138 2,138 — 2,138 — Deferred compensation plan assets 9,566 9,566 — 9,566 — Total financial assets $ 8,018,987 $ 7,983,102 $ 655,528 $ 7,308,211 $ 19,363 Financial liabilities: Total deposits, excluding time deposits $ 6,004,127 $ 6,004,127 $ 6,004,127 $ — $ — Time deposits 1,103,336 1,100,852 — 1,100,852 — Securities sold under repurchase agreements 465,523 465,523 — 465,523 — Other borrowed funds 33 33 — 33 — Accrued interest payable 5,184 5,184 — 5,184 — Long-term debt 27,907 27,662 — 27,662 — Subordinated debentures held by subsidiary trusts 82,477 72,252 — 72,252 — Derivative liabilities 3,619 3,619 — 3,619 — Deferred compensation plan liabilities 9,566 9,566 — 9,566 — Total financial liabilities $ 7,701,772 $ 7,688,818 $ 6,004,127 $ 1,684,691 $ — Fair Value Measurements at Reporting Date Using As of December 31, 2015 Carrying Amount Estimated Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial assets: Cash and cash equivalents $ 780,457 $ 780,457 $ 780,457 $ — $ — Investment securities available-for-sale 1,456,840 1,456,840 — 1,456,840 — Investment securities held-to-maturity 600,665 607,550 — 607,550 — Accrued interest receivable 27,729 27,729 — 27,729 — Mortgage servicing rights, net 15,621 31,011 — 31,011 — Net loans 5,169,379 5,128,705 — 5,107,830 20,875 Derivative assets 953 953 — 953 — Deferred compensation plan assets 10,149 10,149 — 10,149 — Total financial assets $ 8,061,793 $ 8,043,394 $ 780,457 $ 7,242,062 $ 20,875 Financial liabilities: Total deposits, excluding time deposits $ 5,957,345 $ 5,975,345 $ 5,975,345 $ — $ — Time deposits 1,131,592 1,137,289 — 1,137,289 — Securities sold under repurchase agreements 510,635 510,635 — 510,635 — Other borrowed funds 2 2 — 2 — Accrued interest payable 4,960 4,960 — 4,960 — Long-term debt 27,885 27,622 — 27,622 — Subordinated debentures held by subsidiary trusts 82,477 74,969 — 74,969 — Derivative liabilities 829 829 — 829 — Deferred compensation plan liabilities 10,149 10,149 — 10,149 — Total financial liabilities $ 7,725,874 $ 7,741,800 $ 5,975,345 $ 1,766,455 $ —

Recent Authoritative Accounting

Recent Authoritative Accounting Guidance	3 Months Ended
	Mar. 31, 2016
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Recent Authoritative Accounting Guidance	Recent Authoritative Accounting Guidance ASU 2014-09 "Revenue from Contracts with Customers." The amendments in Accounting Standards Update ("ASU") 2014-09 introduce a new five-step revenue recognition model in which an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. ASU 2014-09 also requires disclosures sufficient to enable users to understand the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers, including qualitative and quantitative disclosures about contracts with customers, significant judgments and changes in judgments, and assets recognized from the costs to obtain or fulfill a contract. ASU 2015-14, “Revenue from Contracts with Customers (Topic 606) – Deferral of the Effective Date" was released in August of 2015 deferring the effective date of 2014-09 for all entities by one year until January 1, 2018. The Company is evaluating the new guidance to determine the impact it will have on its consolidated financial statements, results of operations or liquidity. ASU 2014-12 "Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could be Achieved after the Requisite Service Period." ASU 2014-12 amends Accounting Standards Codification ("ASC") Topic 718, Compensation-Stock Compensation, to clarify that a performance target that affects the vesting of a share-based payment award and that could be achieved after the requisite service period should be treated as a performance condition that affects the vesting of the award. ASU 2014-12 further clarifies that the requisite service period ends when the employees can cease rendering service and still be eligible to vest in the award if the performance target is achieved. The Company adopted the amendments in ASU 2014-12 effective January 1, 2016. The adoption did not have a material impact on the Company’s consolidated financial statements, results of operations or liquidity. ASU 2014-16 "Determining Whether the Host Contract in a Hybrid Financial Instrument Issued in the Form of a Share is More Akin to Debt or to Equity." The amendments in ASU 2014-16 clarify that an entity should consider all relevant terms and features-including the embedded derivative feature being evaluated for bifurcation-in evaluating the nature of the host contract within a hybrid financial instrument. The amendments further clarify that no single term or feature would necessarily determine the economic characteristics and risk of the host contract. Rather, the nature of the host contract depends upon the economic characteristics and risk of the entire hybrid financial instrument. The Company adopted the amendments in ASU 2014-16 effective January 1, 2016. The adoption did not have a material impact on the Company’s consolidated financial statements, results of operations or liquidity. ASU 2015-02 "Amendments to the Consolidation Analysis." The amendments in ASU 2015-02 (i) modify the evaluation of whether limited partnerships and similar legal entities are variable interest entities or voting interest entities, (ii) eliminate the presumption that a general partner should consolidate a limited partnership, (iii) affect the consolidation analysis of reporting entities that are involved with variable interest entities, particularly those that have fee arrangements and related party relationships, and (iv) provide scope exceptions from consolidation guidance for reporting entities with interest in legal entities that are required to comply or operate in accordance with requirements of the Investment Company Act of 1940 for registered market funds. The Company adopted the amendments in ASU 2015-02 effective January 1, 2016. The adoption did not have a material impact on the Company’s consolidated financial statements, results of operations or liquidity. ASU 2015-03 "Simplifying the Presentation of Debt Issuance Costs." The amendments in ASU 2015-03 require that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, rather than as a deferred charge. The guidance in ASU 2015-03 did not address presentation or subsequent measurement of debt issues costs related to line-of-credit arrangements. ASU 2015-15, “Interest – Imputation of Interest (Subtopic 835-30) – Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements, Amendments to SEC Paragraphs Pursuant to Staff Announcement at June 18, 2015 EITF Meeting," addresses this gap. ASU 2015-15 adds that the SEC staff would not object to an entity deferring and presenting debt issuance costs as an asset and subsequently amortizing the deferred debt issuance costs ratably over the term of the line-of-credit arrangement, regardless of whether there are any outstanding borrowings on the line-of-credit arrangement. The Company adopted the amendments in ASU 2015-03 and ASU 2015-15 effective January 1, 2016. The adoption did not have a material impact on the Company’s consolidated financial statements, results of operations or liquidity. ASU 2015-05 "Intangibles-Goodwill and Other Internal-Use Software." The amendments in ASU 2015-05 provide guidance about whether a cloud computing arrangement includes a software license. Under the guidance in ASU 2015-05, if a cloud computing arrangement includes a software license, the customer should account for the software license element of the arrangement consistent with the acquisition of other software licenses. If a cloud computing arrangement does not include a software license, the customer should account for the arrangement as a service contract. The Company adopted the amendments in ASU 2015-05 effective January 1, 2016. The adoption did not have a material impact on the Company’s consolidated financial statements, results of operations or liquidity. ASU 2015-10 "Technical Corrections and Improvements." The amendments in ASU 2015-10 represent changes to clarify the codification, correct unintended application of guidance, or make minor improvements to the codification that are not expected to have a significant effect on current accounting practice or create a significant administrative cost to most entities. The Company adopted the amendments in ASU 2015-10 effective January 1, 2016. The adoption did not have a material impact on the Company’s consolidated financial statements, results of operations or liquidity. ASU 2015-16 "Business Combinations-Simplifying the Accounting for Measurement-Period Adjustments." The amendments in ASU 2015-16 eliminate the requirement to retrospectively account for adjustments made to provisional amounts recognized as part of a business combination. Under the amendments in ASU 2015-16, an acquirer must recognize adjustments to the provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined. The amendments in ASU 2015-16 require that the acquirer record, in the same period’s financial statements, the effect on earnings of changes in depreciation, amortization or other income effects, if any, as a result of the change to the provisional amounts, calculated as if the accounting had been completed at the acquisition date. The Company adopted the amendments in ASU 2015-16 effective January 1, 2016. The adoption did not have a material impact on the Company’s consolidated financial statements, results of operations or liquidity. ASU 2016-01 "Financial Instruments-Overall: Recognition and Measurement of Financial Assets and Financial Liabilities." The amendments in ASU 2016-1, among other things, (i) require equity investments, with certain exceptions, to be measured at fair value with changes in fair value recognized in net income, (ii) simplifies the impairment assessment of equity investments without readily determinable fair values by requiring a qualitative assessment to identify impairment, (iii) eliminates the requirement for public business entities to disclose the methods and significant assumptions used to estimate the fair value that is required to be disclosed for financial instruments measured at amortized cost on the balance sheet, (iv) requires public business entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes, (v) requires an entity to present separately in other comprehensive income the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk when the entity has elected to measure the liability at fair value in accordance with the fair value option for financial instruments, (vi) requires separate presentation of financial assets and financial liabilities by measurement category and form of financial asset on the balance sheet or the accompanying notes to the financial statements and (viii) clarifies that an entity should evaluate the need for a valuation allowance on a deferred tax asset related to available-for-sale investment securities. The amendments in ASU 2016-1 will be effective for the Company on January 1, 2018, and are not expected to have a significant impact on the Company’s consolidated financial statements, results of operations or liquidity. ASU 2016-02 "Leases (Topic 842)." On February 25, 2016, the Financial Accounting Standards Board issued new lease accounting guidance in ASU No. 2016-02. Under the new guidance, lessees will be required to recognize a lease liability and a right of use asset for all leases (with the exception of short-term leases) at the commencement date of the lease and disclose key information about leasing arrangements. Accounting by lessors is largely unchanged. ASU 2016-02 will be effective for the Company on January 1, 2019 and will be applied using a modified retrospective approach. The Company is evaluating the new guidance to determine the impact ASU 2016-02 will have on its consolidated financial statements, results of operations or liquidity. ASU 2016-05 "Derivatives and Hedging (Topic 815): Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships." The amendments in ASU 2016-05 clarify that a change in the counterparty to a derivative instrument that has been designated as the hedging instrument under ASC Topic 815 does not, in and of itself, require dedesignation of that hedging relationship provided that all other hedge accounting criteria continue to be met. The amendments in ASU 2016-05 will be effective for the Company on January 1, 2017, and are not expected to have a significant impact on the Company’s consolidated financial statements, results of operations or liquidity. ASU 2016-07 "Investments - Equity Method and Joint Ventures (Topic 323): Simplifying the Transition to the Equity Method of Accounting." The amendments in ASU 2016-07 eliminate the requirement that when an investment qualified for use of the equity method as a result of an increase in the level of ownership interest or degree of influence, an investor must adjust the investments, results of operations and retained earnings retroactively on a step-by-step basis as if the equity method had been in effect during all previous periods hat the investment had been held. The amendments in ASU 2016-07 also simplify the transition to the equity method of accounting by eliminating retroactive adjustment of the investment when an investment qualifies for use of the equity method, among other things. The amendments in ASU 2016-07 will be effective for the Company on January 1, 2017, and are not expected to have a significant impact on on the Company’s consolidated financial statements, results of operations or liquidity. ASU 2016-08 "Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net)." The amendments in ASU 2016-08 were issued to clarify certain principal versus agent considerations within the implementation guidance of ASC Topic 606, “Revenue from Contracts with Customers.” The effective date and transition of ASU 2016-08 is the same as the effective date and transition of ASU 2014-09, Revenue from Contracts with Customers (Topic 606), as discussed above. The Company is continuing to evaluate the new guidance to determine the impact it will have on its consolidated financial statements, results of operations or liquidity. ASU 2016-09 "Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting." Under the amendments in ASU 2016-09, all excess tax benefits and tax deficiencies related to share-based payment awards should be recognized as income tax expense or benefit in the income statement during the period in which they occur. Previously, such amounts were recorded in the pool of excess tax benefits included in additional paid-in capital, if such pool was available. Because excess tax benefits are no longer recognized in additional paid-in capital, the assumed proceeds from applying the treasury stock method when computing earnings per share should exclude the amount of excess tax benefits that would have previously been recognized in additional paid-in capital. Additionally, excess tax benefits should be classified along with other income tax cash flows as an operating activity rather than a financing activity, as was previously the case. The amendments in ASU 2016-09 also provide that an entity can make an entity-wide accounting policy election to either estimate the number of awards that are expected to vest (current GAAP) or account for forfeitures when they occur. The amendments in ASU 2016-09 change the threshold to qualify for equity classification to permit withholding up to the maximum statutory tax rates (rather than the minimum as was previously the case) in the applicable jurisdictions. The amendments in ASU 2016-09 will be effective for the Company on January 1, 2017, and are not expected to have a significant impact on impact on the Company’s consolidated financial statements, results of operations or liquidity. ASU No. 2016-10 "Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing." The amendments in ASU 2016-10 were issued to clarify ASC Topic 606, “Revenue from Contracts with Customers” related to (i) identifying performance obligations; and (ii) the licensing implementation guidance. The effective date and transition of ASU 2016-10 is the same as the effective date and transition of ASU 2014-09, “Revenue from Contracts with Customers (Topic 606),” as discussed above. The Company is continuing to evaluate the new guidance to determine the impact it will have on its consolidated financial statements, results of operations or liquidity.

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2016
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Subsequent events have been evaluated for potential recognition and disclosure through the date financial statements were filed with the Securities and Exchange Commission. On April 18, 2016 , the Company declared a quarterly dividend to common shareholders of $ 0.22 per share, to be paid on May 13, 2016 to shareholders of record as of May 2, 2016 . No other events requiring recognition or disclosure were identified.

Investment Securities (Tables)

Investment Securities (Tables)	3 Months Ended
	Mar. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Amortized Cost and Approximate Fair Values of Investment Securities	The amortized cost and approximate fair values of investment securities are summarized as follows: March 31, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Available-for-Sale: U.S. Treasury notes $ 3,911 $ 24 $ — $ 3,935 Obligations of U.S. government agencies 530,037 1,719 (324 ) 531,432 U.S. agency residential mortgage-backed securities & collateralized mortgage obligations 1,010,675 14,550 (862 ) 1,024,363 Private mortgage-backed securities 144 1 (2 ) 143 Other investments 3,450 27 — 3,477 Total $ 1,548,217 $ 16,321 $ (1,188 ) $ 1,563,350 March 31, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Held-to-Maturity: State, county and municipal securities $ 167,975 $ 5,553 $ (14 ) $ 173,514 Corporate securities 51,918 292 (61 ) 52,149 U.S agency residential mortgage-backed securities & collateralized mortgage obligations 341,434 11,640 (5,145 ) 347,929 Obligations of U.S. government agencies 19,737 248 — 19,985 Other investments 326 1 — 327 Total $ 581,390 $ 17,734 $ (5,220 ) $ 593,904 December 31, 2015 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Available-for-Sale: U.S. Treasury notes $ 3,912 $ 3 $ (4 ) $ 3,911 Obligations of U.S. government agencies 521,079 712 (1,610 ) 520,181 U.S. agency residential mortgage-backed securities & collateralized mortgage obligations 921,699 9,448 (2,101 ) 929,046 Private mortgage-backed securities 156 1 (1 ) 156 Other investments 3,550 5 (9 ) 3,546 Total $ 1,450,396 $ 10,169 $ (3,725 ) $ 1,456,840 December 31, 2015 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Held-to-Maturity: State, county and municipal securities $ 173,785 $ 5,103 $ (227 ) $ 178,661 Corporate securities 50,046 64 (220 ) 49,890 U.S. agency residential mortgage-backed securities & collateralized mortgage obligations 356,742 7,686 (5,420 ) 359,008 Obligations of U.S. government agencies 19,738 — (102 ) 19,636 Other investments 354 1 — 355 Total $ 600,665 $ 12,854 $ (5,969 ) $ 607,550
Realized Gains (Losses) on Investments	Gross realized gains and losses from the disposition of investment securities are summarized in the following table: Three Months Ended March 31, 2016 2015 Gross realized gains $ 57 $ 6 Gross realized losses (78 ) —
Gross Unrealized Losses and Fair Values of Investment Securities	The following tables show the gross unrealized losses and fair values of investment securities, aggregated by investment category, and the length of time individual investment securities have been in a continuous unrealized loss position, as of March 31, 2016 and December 31, 2015 . Less than 12 Months 12 Months or More Total March 31, 2016 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Available-for-Sale: Obligations of U.S. government agencies $ 118,698 $ (226 ) $ 35,355 $ (98 ) $ 154,053 $ (324 ) U.S. agency residential mortgage-backed securities & collateralized mortgage obligations 146,840 (586 ) 25,708 (276 ) 172,548 (862 ) Private mortgage-backed securities — — 57 (2 ) 57 (2 ) Other investments — — — — — — Total $ 265,538 $ (812 ) $ 61,120 $ (376 ) $ 326,658 $ (1,188 ) Less than 12 Months 12 Months or More Total March 31, 2016 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Held-to-Maturity: State, county and municipal securities $ 3,379 $ (7 ) $ 3,606 $ (7 ) $ 6,985 $ (14 ) U.S. agency residential mortgage-backed securities & collateralized mortgage obligations 13,801 (4,364 ) 24,049 (781 ) 37,850 (5,145 ) Corporate securities 10,049 (61 ) — — 10,049 (61 ) Total $ 27,229 $ (4,432 ) $ 27,655 $ (788 ) $ 54,884 $ (5,220 ) Less than 12 Months 12 Months or More Total December 31, 2015 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Available-for-Sale: U.S. Treasury notes $ 2,092 $ (4 ) $ — $ — $ 2,092 $ (4 ) Obligations of U.S. government agencies 209,631 (1,077 ) 54,619 (533 ) 264,250 (1,610 ) U.S. agency residential mortgage-backed securities & collateralized mortgage obligations 343,875 (1,577 ) 28,010 (524 ) 371,885 (2,101 ) Private mortgage-backed securities — — 61 (1 ) 61 (1 ) Other investments 1,225 (9 ) — — 1,225 (9 ) Total $ 556,823 $ (2,667 ) $ 82,690 $ (1,058 ) $ 639,513 $ (3,725 ) Less than 12 Months 12 Months or More Total December 31, 2015 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Held-to-Maturity: State, county and municipal securities $ 10,182 $ (39 ) $ 9,476 $ (188 ) $ 19,658 $ (227 ) U.S. agency residential mortgage-backed securities & collateralized mortgage obligations 67,295 (4,288 ) 69,539 (1,132 ) 136,834 (5,420 ) Obligations of U.S. government agencies 19,738 (102 ) — — 19,738 (102 ) Corporate securities 31,135 (220 ) — — 31,135 (220 ) Total $ 128,350 $ (4,649 ) $ 79,015 $ (1,320 ) $ 207,365 $ (5,969 )
Maturities of Investment Securities	Maturities of investment securities at March 31, 2016 are shown below. Maturities of mortgage-backed securities have been adjusted to reflect shorter maturities based upon estimated prepayments of principal. All other investment securities maturities are shown at contractual maturity dates. Available-for-Sale Held-to-Maturity March 31, 2016 Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair Value Within one year $ 317,502 $ 320,927 $ 87,930 $ 90,154 After one year but within five years 1,089,290 1,099,333 328,090 333,231 After five years but within ten years 70,534 71,242 125,412 128,977 After ten years 70,891 71,848 39,958 41,542 Total $ 1,548,217 $ 1,563,350 $ 581,390 $ 593,904

Loans (Tables)

Loans (Tables)	3 Months Ended
	Mar. 31, 2016
Receivables [Abstract]
Schedule of Loans by Class	March 31, December 31, Real estate loans: Commercial $ 1,764,492 $ 1,793,258 Construction: Land acquisition & development 219,450 224,066 Residential 113,317 111,763 Commercial 102,382 94,890 Total construction loans 435,149 430,719 Residential 1,021,443 1,032,851 Agricultural 153,054 156,234 Total real estate loans 3,374,138 3,413,062 Consumer: Indirect consumer 651,057 622,529 Other consumer 150,774 153,717 Credit card 63,624 68,107 Total consumer loans 865,455 844,353 Commercial 825,043 792,416 Agricultural 126,290 142,151 Other, including overdrafts 543 1,339 Loans held for investment 5,191,469 5,193,321 Mortgage loans held for sale 52,989 52,875 Total loans $ 5,244,458 $ 5,246,196
Schedule of acquired loans with credit impairment	The following table displays the outstanding unpaid principal balance, accrued interest receivable and accrual status of loans acquired with credit impairment as of March 31, 2016 and 2015 : As of March 31, 2016 2015 Outstanding balance $ 33,175 $ 32,445 Carrying value Loans on accrual status 21,064 23,909 Loans on non-accrual status — — Total carrying value $ 21,064 $ 23,909 The following table summarizes changes in the accretable yield for loans acquired credit impaired for the three months ended March 31, 2016 and 2015 : Three Months Ended March 31, 2016 2015 Beginning balance $ 6,713 $ 5,781 Accretion income (614 ) (548 ) Reductions due to exit events (147 ) (396 ) Reclassifications from nonaccretable differences 726 2,143 Ending balance $ 6,678 $ 6,980
Schedule of Recorded Investment in Past Due Loans by Class	The following tables present the contractual aging of the Company’s recorded investment in past due loans by class as of the dates indicated: Total Loans 30 - 59 60 - 89 > 90 30 or More Days Days Days Days Current Non-accrual Total As of March 31, 2016 Past Due Past Due Past Due Past Due Loans Loans Loans Real estate Commercial $ 2,302 $ 2,975 $ 5 $ 5,282 $ 1,736,374 $ 22,836 $ 1,764,492 Construction: Land acquisition & development 951 351 857 2,159 210,994 6,297 219,450 Residential 96 — — 96 112,166 1,055 113,317 Commercial 184 — — 184 101,915 283 102,382 Total construction loans 1,231 351 857 2,439 425,075 7,635 435,149 Residential 4,804 985 1,750 7,539 1,010,803 3,101 1,021,443 Agricultural 27 — — 27 147,423 5,604 153,054 Total real estate loans 8,364 4,311 2,612 15,287 3,319,675 39,176 3,374,138 Consumer: Indirect consumer 4,448 1,075 188 5,711 644,517 829 651,057 Other consumer 613 226 38 877 149,419 478 150,774 Credit card 412 346 529 1,287 62,325 12 63,624 Total consumer loans 5,473 1,647 755 7,875 856,261 1,319 865,455 Commercial 2,144 763 232 3,139 799,325 22,579 825,043 Agricultural 1,972 322 451 2,745 122,782 763 126,290 Other, including overdrafts — 5 312 317 226 — 543 Loans held for investment 17,953 7,048 4,362 29,363 5,098,269 63,837 5,191,469 Mortgage loans originated for sale — — — — 52,989 — 52,989 Total loans $ 17,953 $ 7,048 $ 4,362 $ 29,363 $ 5,151,258 $ 63,837 $ 5,244,458 Total Loans 30 - 59 60 - 89 > 90 30 or More Days Days Days Days Current Non-accrual Total As of December 31, 2015 Past Due Past Due Past Due Past Due Loans Loans Loans Real estate Commercial $ 6,051 $ 724 $ 418 $ 7,193 $ 1,762,294 $ 23,771 $ 1,793,258 Construction: Land acquisition & development 3,190 163 1,325 4,678 212,757 6,631 224,066 Residential 1,288 — — 1,288 110,182 293 111,763 Commercial 3,232 — — 3,232 90,703 955 94,890 Total construction loans 7,710 163 1,325 9,198 413,642 7,879 430,719 Residential 5,991 1,196 2,063 9,250 1,018,359 5,242 1,032,851 Agricultural 176 17 — 193 150,686 5,355 156,234 Total real estate loans 19,928 2,100 3,806 25,834 3,344,981 42,247 3,413,062 Consumer: Indirect consumer 6,675 1,089 210 7,974 614,029 526 622,529 Other consumer 1,312 331 34 1,677 151,381 659 153,717 Credit card 533 317 477 1,327 66,768 12 68,107 Total consumer loans 8,520 1,737 721 10,978 832,178 1,197 844,353 Commercial 8,493 1,060 699 10,252 759,851 22,313 792,416 Agricultural 879 152 62 1,093 140,430 628 142,151 Other, including overdrafts — — 314 314 1,025 — 1,339 Loans held for investment 37,820 5,049 5,602 48,471 5,078,465 66,385 5,193,321 Mortgage loans originated for sale — — — — 52,875 — 52,875 Total loans $ 37,820 $ 5,049 $ 5,602 $ 48,471 $ 5,131,340 $ 66,385 $ 5,246,196
Schedule of Recorded Investment in Impaired Loans	The following tables present information on the Company’s recorded investment in impaired loans as of dates indicated: As of March 31, 2016 Unpaid Total Principal Balance Recorded Investment With No Allowance Recorded Investment With Allowance Total Recorded Investment Related Allowance Real estate: Commercial $ 55,222 $ 25,759 $ 18,117 $ 43,876 $ 4,526 Construction: Land acquisition & development 15,252 7,742 322 8,064 150 Residential 988 282 — 282 — Commercial 1,370 446 731 1,177 739 Total construction loans 17,610 8,470 1,053 9,523 889 Residential 5,664 3,019 1,152 4,171 160 Agricultural 6,685 5,816 201 6,017 7 Total real estate loans 85,181 43,064 20,523 63,587 5,582 Commercial 28,782 8,113 16,150 24,263 8,176 Agricultural 908 250 544 794 189 Total $ 114,871 $ 51,427 $ 37,217 $ 88,644 $ 13,947 As of December 31, 2015 Unpaid Total Principal Balance Recorded Investment With No Allowance Recorded Investment With Allowance Total Recorded Investment Related Allowance Real estate: Commercial $ 58,179 $ 27,882 $ 17,614 $ 45,496 $ 3,401 Construction: Land acquisition & development 15,503 7,245 778 8,023 282 Residential 992 293 — 293 — Commercial 1,264 340 739 1,079 739 Total construction loans 17,759 7,878 1,517 9,395 1,021 Residential 7,073 3,547 2,317 5,864 367 Agricultural 6,434 5,563 198 5,761 5 Total real estate loans 89,445 44,870 21,646 66,516 4,794 Commercial 29,593 10,744 13,727 24,471 6,487 Agricultural 1,349 622 356 978 294 Total $ 120,387 $ 56,236 $ 35,729 $ 91,965 $ 11,575 The following table presents the average recorded investment in and income recognized on impaired loans for the periods indicated: Three Months Ended March 31, 2016 2015 Average Recorded Investment Income Recognized Average Recorded Investment Income Recognized Real estate: Commercial $ 33,483 $ 36 $ 42,077 $ 150 Construction: Land acquisition & development 7,508 7 8,930 10 Residential 288 — 308 — Commercial 1,067 — 3,055 2 Total construction loans 8,863 7 12,293 12 Residential 4,206 1 3,127 1 Agricultural 5,748 1 8,655 22 Total real estate loans 52,300 45 66,152 185 Commercial 23,379 15 17,533 8 Agricultural 856 — 914 5 Total $ 76,535 $ 60 $ 84,599 $ 198
Schedule of Loans Renegotiated in Troubled Debt Restructurings	The Company considers a payment default to occur on troubled debt restructurings when the loan is 90 days or more past due or was placed on non-accrual status after the modification. Three Months Ended March 31, 2016 Number of Notes Balance Commercial Real Estate 1 $ 203 Total 1 $ 203 Number of Notes Type of Concession Principal Balance at Restructure Date Three Months Ended March 31, 2016 Interest only period Extension of terms or maturity Commercial Real Estate 3 $ 576 $ 204 $ 780 Total loans restructured during period 3 $ 576 $ 204 $ 780
Schedule of Recorded Investment in Criticized Loans by Class and Credit Quality Indicator	The following tables present the Company’s recorded investment in criticized loans by class and credit quality indicator based on the most recent analysis performed as of the dates indicated: As of March 31, 2016 Other Assets Especially Mentioned Substandard Doubtful Total Criticized Loans Real estate: Commercial $ 77,147 $ 82,536 $ 14,311 $ 173,994 Construction: Land acquisition & development 11,854 11,226 1,515 24,595 Residential 2,003 389 — 2,392 Commercial 4,056 429 748 5,233 Total construction loans 17,913 12,044 2,263 32,220 Residential 5,681 10,107 477 16,265 Agricultural 7,519 18,920 — 26,439 Total real estate loans 108,260 123,607 17,051 248,918 Consumer: Indirect consumer 704 1,446 144 2,294 Other consumer 1,024 914 211 2,149 Total consumer loans 1,728 2,360 355 4,443 Commercial 31,392 34,039 16,629 82,060 Agricultural 3,613 7,820 543 11,976 Total $ 144,993 $ 167,826 $ 34,578 $ 347,397 As of December 31, 2015 Other Assets Especially Mentioned Substandard Doubtful Total Criticized Loans Real estate: Commercial $ 61,787 $ 84,556 $ 10,609 $ 156,952 Construction: Land acquisition & development 16,593 12,482 591 29,666 Residential 1,640 1,886 — 3,526 Commercial 166 323 756 1,245 Total construction loans 18,399 14,691 1,347 34,437 Residential 4,453 9,661 2,540 16,654 Agricultural 6,114 16,529 — 22,643 Total real estate loans 90,753 125,437 14,496 230,686 Consumer: Indirect consumer 644 1,131 154 1,929 Other consumer 651 1,130 198 1,979 Total consumer loans 1,295 2,261 352 3,908 Commercial 32,975 27,982 15,085 76,042 Agricultural 2,247 7,105 417 9,769 Total $ 127,270 $ 162,785 $ 30,350 $ 320,405

Allowance for Loan Losses (Tabl

Allowance for Loan Losses (Tables)	3 Months Ended
	Mar. 31, 2016
Receivables [Abstract]
Schedule of Allowance for Loan Losses by Portfolio Segment	The following tables present a summary of changes in the allowance for loan losses by portfolio segment for the periods indicated. Three Months Ended March 31, 2016 Real Estate Consumer Commercial Agriculture Other Total Allowance for loan losses: Beginning balance $ 52,296 $ 5,144 $ 18,775 $ 602 $ — $ 76,817 Provision charged to operating expense (16,081 ) 1,229 17,690 1,162 — 4,000 Less loans charged-off (1,922 ) (1,892 ) (488 ) — — (4,302 ) Add back recoveries of loans previously charged-off 2,359 775 275 — — 3,409 Ending balance $ 36,652 $ 5,256 $ 36,252 $ 1,764 $ — $ 79,924 As of March 31, 2016 Real Estate Consumer Commercial Agriculture Other Total Allowance for loan losses: Loans individually evaluated for impairment $ 5,582 $ — $ 8,176 $ 189 $ — $ 13,947 Loans collectively evaluated for impairment 31,070 5,256 28,076 1,575 — 65,977 Allowance for loan losses $ 36,652 $ 5,256 $ 36,252 $ 1,764 $ — $ 79,924 Individually evaluated for impairment $ 63,587 $ — $ 24,263 $ 794 $ — $ 88,644 Collectively evaluated for impairment 3,310,551 865,455 800,780 125,496 543 5,102,825 Total loans $ 3,374,138 $ 865,455 $ 825,043 $ 126,290 $ 543 $ 5,191,469 Three Months Ended March 31, 2015 Real Estate Consumer Commercial Agriculture Other Total Allowance for loan losses: Beginning balance $ 53,884 $ 5,035 $ 14,307 $ 974 $ — $ 74,200 Provision charged to operating expense (1,031 ) 1,125 993 8 — 1,095 Less loans charged-off (186 ) (1,301 ) (374 ) — — (1,861 ) Add back recoveries of loans previously charged-off 992 640 270 — — 1,902 Ending balance $ 53,659 $ 5,499 $ 15,196 $ 982 $ — $ 75,336 As of December 31, 2015 Real Estate Consumer Commercial Agriculture Other Total Allowance for loan losses: Loans individually evaluated for impairment $ 4,794 $ — $ 6,487 $ 294 $ — $ 11,575 Loans collectively evaluated for impairment 47,502 5,144 12,288 308 — 65,242 Allowance for loan losses $ 52,296 $ 5,144 $ 18,775 $ 602 $ — $ 76,817 Total loans: Individually evaluated for impairment $ 66,516 $ — $ 24,471 $ 978 $ — $ 91,965 Collectively evaluated for impairment 3,346,546 844,353 767,945 141,173 1,339 5,101,356 Total loans $ 3,413,062 $ 844,353 $ 792,416 $ 142,151 $ 1,339 $ 5,193,321

OREO (Tables)

OREO (Tables)	3 Months Ended
	Mar. 31, 2016
Repossessed Assets [Abstract]
Other Real Estate Owned Roll Forward	Information with respect to the Company's other real estate owned follows: Three Months Ended March 31, 2016 2015 Beginning balance $ 6,254 $ 13,554 Additions 3,227 3,257 Valuation adjustments (17 ) (106 ) Dispositions (207 ) (1,571 ) Ending balance $ 9,257 $ 15,134 Foreclosed residential real estate properties of $ 4,087 and $1,686 were included in other real estate owned as of March 31, 2016 and December 31, 2015, respectively. The Company did not have any consumer mortgage loans collateralized by residential real estate property that were in the process of foreclosure as of March 31, 2016 or December 31, 2015.

Derivatives and Hedging (Tables

Derivatives and Hedging (Tables)	3 Months Ended
	Mar. 31, 2016
Derivative [Line Items]
Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block]	March 31, 2016 December 31, 2015 Notional Amount Estimated Fair Value Notional Amount Estimated Fair Value Derivative Assets (included in other assets on balance sheet): Derivatives designated as hedges: Interest rate swap contracts $ — $ — $ 100,000 $ 165 Non-hedging interest rate derivatives: Interest rate swap contracts 9,281 1,102 9,369 788 Interest rate lock commitments 112,705 1,036 — — Total derivative assets $ 121,986 $ 2,138 $ 109,369 $ 953 Derivative Liabilities (included in accounts payable and accrued expenses on balance sheet): Derivatives designated as hedges: Interest rate swap contracts $ 100,000 $ 2,032 $ — $ — Non-hedging interest rate derivatives: Interest rate swap contracts 9,281 1,173 9,369 829 Forward loan sales contracts 77,329 414 — — Total derivative liabilities $ 186,610 $ 3,619 $ 9,369 $ 829
Schedule of Derivative Instruments, Effect on Other Comprehensive Income (Loss) [Table Text Block]	Three months ended March 31, 2016 March 31, 2015 Derivatives designated as hedges: Amount of loss recognized in other comprehensive income (effective portion) $ (2,197 ) $ — Non-hedging interest rate derivatives: Amount of loss recognized in other non-interest income (29 ) (7 ) Amount of gains recognized in mortgage banking revenues 695 —

Earnings per Share (Tables)

Earnings per Share (Tables)	3 Months Ended
	Mar. 31, 2016
Earnings Per Share [Abstract]
Computation of Basic and Diluted Earnings per Share	The following table sets forth the computation of basic and diluted earnings per share for the three month periods ended March 31, 2016 and 2015 . Three Months Ended March 31, 2016 2015 Net income $ 20,124 $ 20,980 Weighted average common shares outstanding for basic earnings per share computation 44,719,218 45,378,230 Dilutive effects of stock-based compensation 394,834 461,961 Weighted average common shares outstanding for diluted earnings per common share computation 45,114,052 45,840,191 Basic earnings per common share $ 0.45 $ 0.46 Diluted earnings per common share $ 0.45 $ 0.46

Regulatory Capital (Tables)

Regulatory Capital (Tables)	3 Months Ended
	Mar. 31, 2016
Banking and Thrift [Abstract]
Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations	Actual capital amounts and ratios for the Company and its bank subsidiary, as of March 31, 2016 and December 31, 2015 are presented in the following tables: Actual Adequately Capitalized Basel III Phase-In Schedule Adequately Capitalized Basel III Fully Phased-In Well Capitalized (1) Amount Ratio Amount Ratio Amount Ratio Amount Ratio March 31, 2016 Total risk-based capital: Consolidated $ 930,048 15.0 % $ 533,419 8.6 % $ 649,379 10.5 % $ 618,456 10.0 % FIB 876,265 14.2 531,493 8.6 647,035 10.5 616,224 10.0 Tier 1 risk-based capital: Consolidated 848,709 13.7 409,727 6.6 525,688 8.5 494,765 8.0 FIB 799,201 13.0 408,248 6.6 523,790 8.5 492,979 8.0 Common equity tier 1 risk-based capital: Consolidated 768,709 12.4 316,959 5.1 432,919 7.0 401,997 6.5 FIB 799,201 13.0 315,815 5.1 431,357 7.0 400,546 6.5 Leverage capital ratio: Consolidated 848,709 10.1 337,137 4.0 337,137 4.0 421,421 5.0 FIB 799,201 9.5 336,258 4.0 336,258 4.0 420,322 5.0 Actual Adequately Capitalized Basel III Phase-In Schedule Adequately Capitalized Basel III Fully Phased-In Well Capitalized (1) Amount Ratio Amount Ratio Amount Ratio Amount Ratio December 31, 2015 Total risk-based capital: Consolidated $ 946,156 15.4 % $ 492,692 8.0 % $ 646,658 10.5 % $ 615,865 10.0 % FIB 882,504 14.4 490,866 8.0 644,262 10.5 613,582 10.0 Tier 1 risk-based capital: Consolidated 861,339 14.0 369,519 6.0 523,485 8.5 $ 492,692 8.0 FIB 805,805 13.1 368,149 6.0 521,545 8.5 490,866 8.0 Common equity tier 1 risk-based capital: Consolidated 781,339 12.7 277,139 4.5 431,105 7.0 $ 400,312 6.5 FIB 805,805 13.1 276,112 4.5 429,508 7.0 398,829 6.5 Leverage capital ratio: Consolidated 861,339 10.1 340,480 4.0 340,480 4.0 $ 425,600 5.0 FIB 805,805 9.5 339,316 4.0 339,316 4.0 424,145 5.0 (1) The ratios for the well capitalized requirement are only applicable to FIB. However, the Company manages its capital position as if the requirement applies to the consolidated entity and has presented the ratios as if they also applied on a consolidated basis.

Other Comprehensive Income (Tab

Other Comprehensive Income (Tables)	3 Months Ended
	Mar. 31, 2016
Equity [Abstract]
Schedule of Comprehensive Income (Loss)	Other Comprehensive Income/Loss The gross amounts of each component of other comprehensive income and the related tax effects are as follows: Pre-tax Tax Expense (Benefit) Net of Tax Three Months Ended March 31, 2016 2015 2016 2015 2016 2015 Investment securities available-for sale: Change in net unrealized gains during period $ 8,613 $ 10,608 $ 3,360 $ 4,174 $ 5,253 $ 6,434 Reclassification adjustment for net (gains) losses included in net income 21 (6 ) 8 (2 ) 13 (4 ) Change in unamortized loss on available- for-sale securities transferred into held-to- maturity 465 451 183 177 282 274 Unrealized loss on derivatives (2,197 ) — (835 ) — (1,362 ) — Defined benefits post-retirement benefit plan: Change in net actuarial loss 15 15 6 6 9 9 Total other comprehensive income (loss) $ 6,917 $ 11,068 $ 2,722 $ 4,355 $ 4,195 $ 6,713
Schedule of Accumulated Other Comprehensive Income (Loss)	The components of accumulated other comprehensive income, net of related tax effects, are as follows: March 31, December 31, Net unrealized gain on investment securities available-for-sale $ 6,232 $ 684 Net unrealized gain (loss) on derivatives (1,262 ) 100 Net actuarial loss on defined benefit post-retirement benefit plans (369 ) (378 ) Net accumulated other comprehensive income $ 4,601 $ 406

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2016
Fair Value Disclosures [Abstract]
Schedule of Financial Assets and Financial Liabilities Measured at Fair Value on a Recurring Basis	Financial assets and financial liabilities measured at fair value on a recurring basis are as follows: Fair Value Measurements at Reporting Date Using As of March 31, 2016 Balance Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Investment securities available-for-sale: U.S. Treasury Notes $ 3,935 $ — $ 3,935 $ — Obligations of U.S. government agencies 531,432 — 531,432 — U.S. agencies mortgage-backed securities & collateralized mortgage obligations 1,024,363 — 1,024,363 — Private mortgage-backed securities 143 — 143 — Other investments 3,477 — 3,477 — Loans held for sale 52,989 — 52,989 — Derivative assets: Interest rate swap contracts 1,102 — 1,102 — Interest rate lock commitments 1,036 — 1,036 — Derivative liabilities: Interest rate swap contracts 3,205 — 3,205 — Forward loan sale contracts 414 — 414 — Deferred compensation plan assets 9,566 — 9,566 — Deferred compensation plan liabilities 9,566 — 9,566 — Fair Value Measurements at Reporting Date Using As of December 31, 2015 Balance Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Investment securities available-for-sale: U.S. Treasury notes $ 3,911 $ — $ 3,911 $ — Obligations of U.S. government agencies 520,181 — 520,181 — U.S. agencies mortgage-backed securities & collateralized mortgage obligations 929,046 — 929,046 — Private mortgage-backed securities 156 — 156 — Other investments 3,546 — 3,546 — Derivative assets: Interest rate swap contracts 953 — 953 — Derivative liabilities Interest rate swap contracts 829 — 829 — Deferred compensation plan assets 10,149 — 10,149 — Deferred compensation plan liabilities 10,149 — 10,149 —
Schedule of Financial Assets and Financial Liabilities Measured at Fair Value on a Non-Recurring Basis	The following table presents information about the Company’s assets and liabilities measured at fair value on a non-recurring basis. Fair Value Measurements at Reporting Date Using As of March 31, 2016 Balance Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Impaired loans $ 19,363 $ — $ — $ 19,363 Other real estate owned 3,464 — — 3,464 Long-lived assets to be disposed of by sale 1,506 — — 1,506 Fair Value Measurements at Reporting Date Using As of December 31, 2015 Balance Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Impaired loans $ 20,875 $ — $ — $ 20,875 Other real estate owned 1,789 — — 1,789 Long-lived assets to be disposed of by sale 1,506 — — 1,506
Fair Value Inputs, Assets, Quantitative Information	Fair Value As of March 31, 2016 December 31, 2015 Valuation Technique Unobservable Inputs Range (Weighted Average) Impaired loans $ 19,363 $ 20,875 Appraisal Appraisal adjustment 0% - 53% (38%) Other real estate owned 3,464 1,789 Appraisal Appraisal adjustment 2% - 96% (19%) Long-lived assets to be disposed of by sale 1,506 1,506 Appraisal Appraisal adjustment 0% - 9% (6%)
Fair Value, by Balance Sheet Grouping	Fair Value Measurements at Reporting Date Using As of March 31, 2016 Carrying Amount Estimated Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial assets: Cash and cash equivalents $ 655,528 $ 655,528 $ 655,528 $ — $ — Investment securities available-for-sale 1,563,350 1,563,350 — 1,563,350 — Investment securities held-to-maturity 581,390 593,904 — 593,904 — Accrued interest receivable 26,907 26,907 — 26,907 — Mortgage servicing rights, net 15,574 26,359 — 26,359 — Net loans 5,164,534 5,105,350 — 5,085,987 19,363 Derivative assets 2,138 2,138 — 2,138 — Deferred compensation plan assets 9,566 9,566 — 9,566 — Total financial assets $ 8,018,987 $ 7,983,102 $ 655,528 $ 7,308,211 $ 19,363 Financial liabilities: Total deposits, excluding time deposits $ 6,004,127 $ 6,004,127 $ 6,004,127 $ — $ — Time deposits 1,103,336 1,100,852 — 1,100,852 — Securities sold under repurchase agreements 465,523 465,523 — 465,523 — Other borrowed funds 33 33 — 33 — Accrued interest payable 5,184 5,184 — 5,184 — Long-term debt 27,907 27,662 — 27,662 — Subordinated debentures held by subsidiary trusts 82,477 72,252 — 72,252 — Derivative liabilities 3,619 3,619 — 3,619 — Deferred compensation plan liabilities 9,566 9,566 — 9,566 — Total financial liabilities $ 7,701,772 $ 7,688,818 $ 6,004,127 $ 1,684,691 $ — Fair Value Measurements at Reporting Date Using As of December 31, 2015 Carrying Amount Estimated Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial assets: Cash and cash equivalents $ 780,457 $ 780,457 $ 780,457 $ — $ — Investment securities available-for-sale 1,456,840 1,456,840 — 1,456,840 — Investment securities held-to-maturity 600,665 607,550 — 607,550 — Accrued interest receivable 27,729 27,729 — 27,729 — Mortgage servicing rights, net 15,621 31,011 — 31,011 — Net loans 5,169,379 5,128,705 — 5,107,830 20,875 Derivative assets 953 953 — 953 — Deferred compensation plan assets 10,149 10,149 — 10,149 — Total financial assets $ 8,061,793 $ 8,043,394 $ 780,457 $ 7,242,062 $ 20,875 Financial liabilities: Total deposits, excluding time deposits $ 5,957,345 $ 5,975,345 $ 5,975,345 $ — $ — Time deposits 1,131,592 1,137,289 — 1,137,289 — Securities sold under repurchase agreements 510,635 510,635 — 510,635 — Other borrowed funds 2 2 — 2 — Accrued interest payable 4,960 4,960 — 4,960 — Long-term debt 27,885 27,622 — 27,622 — Subordinated debentures held by subsidiary trusts 82,477 74,969 — 74,969 — Derivative liabilities 829 829 — 829 — Deferred compensation plan liabilities 10,149 10,149 — 10,149 — Total financial liabilities $ 7,725,874 $ 7,741,800 $ 5,975,345 $ 1,766,455 $ —

Business Combination (Details)

Business Combination (Details) $ in Thousands	Apr. 06, 2016	Jul. 24, 2015	Mar. 31, 2016USD ($)	Mar. 31, 2015USD ($)	Dec. 31, 2015USD ($)
Business Acquisition [Line Items]
Assets			$ 8,690,680		$ 8,728,196
Loans and Leases Receivable, Net Amount			5,164,534		5,169,379
Deposits			7,107,463		7,088,937
Goodwill			204,481		$ 204,523
Business Combination, Acquisition Related Costs			0	$ 70
Flathead Bank [Member]
Business Acquisition [Line Items]
Estimate of Payments to Acquire Businesses, Gross			34,237
Assets			$ 231,574
United Bank [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition		Jul. 24, 2015
Number of Subsidiary Banks			1
Goodwill, Purchase Accounting Adjustments			$ 42
Subsequent Event [Member] | United Bank [Member]
Business Acquisition [Line Items]
Business Acquisition, Date of Acquisition Agreement	Apr. 6, 2016

Amortized Cost and Approximate

Amortized Cost and Approximate Fair Values of Investment Securities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Schedule of Available for Sale and Held-to-Maturity Securities [Line Items]
Available-for-Sale Securities, Gross Realized Gains	$ 57	$ 6
Available-for-sale Securities, Gross Realized Losses	78	$ 0
Available-for-Sale:
Available-for-Sale, Amortized Cost	1,548,217		$ 1,450,396
Available-for-sale Securities, Gross Unrealized Gain1	16,321		10,169
Available-for-sale Securities, Gross Unrealized Loss1	(1,188)		(3,725)
Available-for-Sale, Estimated Fair Value	1,563,350		1,456,840
Held-to-Maturity:
Held-to-Maturity, Amortized Cost	581,390		600,665
Held-to-maturity Securities, Gross Unrealized Gain1	17,734		12,854
Held-to-maturity Securities, Gross Unrealized Loss1	(5,220)		(5,969)
Held-to-Maturity, Estimated Fair Value	593,904		607,550
US Treasury Securities [Member]
Available-for-Sale:
Available-for-Sale, Amortized Cost	3,911
Available-for-sale Securities, Gross Unrealized Gain1	24
Available-for-sale Securities, Gross Unrealized Loss1	0
Available-for-Sale, Estimated Fair Value	3,935
Obligations of U.S. government agencies
Available-for-Sale:
Available-for-Sale, Amortized Cost	530,037		521,079
Available-for-sale Securities, Gross Unrealized Gain1	1,719		712
Available-for-sale Securities, Gross Unrealized Loss1	(324)		(1,610)
Available-for-Sale, Estimated Fair Value	531,432		520,181
Held-to-Maturity:
Held-to-Maturity, Amortized Cost	19,737		19,738
Held-to-maturity Securities, Gross Unrealized Gain1	248		0
Held-to-maturity Securities, Gross Unrealized Loss1	0		(102)
Held-to-Maturity, Estimated Fair Value	19,985		19,636
U.S. agency residential mortgage-backed securities & collateralized mortgage obligations
Available-for-Sale:
Available-for-Sale, Amortized Cost	1,010,675		921,699
Available-for-sale Securities, Gross Unrealized Gain1	14,550		9,448
Available-for-sale Securities, Gross Unrealized Loss1	(862)		(2,101)
Available-for-Sale, Estimated Fair Value	1,024,363		929,046
Held-to-Maturity:
Held-to-Maturity, Amortized Cost	341,434		356,742
Held-to-maturity Securities, Gross Unrealized Gain1	11,640		7,686
Held-to-maturity Securities, Gross Unrealized Loss1	(5,145)		(5,420)
Held-to-Maturity, Estimated Fair Value	347,929		359,008
Private mortgage-backed securities
Available-for-Sale:
Available-for-Sale, Amortized Cost	144		156
Available-for-sale Securities, Gross Unrealized Gain1	1		1
Available-for-sale Securities, Gross Unrealized Loss1	(2)		(1)
Available-for-Sale, Estimated Fair Value	143		156
State, county and municipal securities
Held-to-Maturity:
Held-to-Maturity, Amortized Cost	167,975		173,785
Held-to-maturity Securities, Gross Unrealized Gain1	5,553		5,103
Held-to-maturity Securities, Gross Unrealized Loss1	(14)		(227)
Held-to-Maturity, Estimated Fair Value	173,514		178,661
Corporate securities
Held-to-Maturity:
Held-to-Maturity, Amortized Cost	51,918		50,046
Held-to-maturity Securities, Gross Unrealized Gain1	292		64
Held-to-maturity Securities, Gross Unrealized Loss1	(61)		(220)
Held-to-Maturity, Estimated Fair Value	52,149		49,890
Other Investments
Held-to-Maturity:
Held-to-Maturity, Amortized Cost	326		354
Held-to-maturity Securities, Gross Unrealized Gain1	1		1
Held-to-maturity Securities, Gross Unrealized Loss1	0		0
Held-to-Maturity, Estimated Fair Value	327		355
Other Investments
Available-for-Sale:
Available-for-Sale, Amortized Cost	3,450		3,550
Available-for-sale Securities, Gross Unrealized Gain1	27		5
Available-for-sale Securities, Gross Unrealized Loss1	0		(9)
Available-for-Sale, Estimated Fair Value	$ 3,477		$ 3,546

Investment Securities Realized

Investment Securities Realized Gains (Losses) on Investments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Gross realized gains	$ 57	$ 6
Gross realized losses	$ (78)	$ 0

Investment Securities Gross Unr

Investment Securities Gross Unrealized Losses and Fair Values of Investment Securities (Details) $ in Thousands	Mar. 31, 2016USD ($)securities	Dec. 31, 2015USD ($)
Available-for-Sale:
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 265,538	$ 556,823
Available-for-sale Securities, Continuous Unrealized Loss Position, Less Than 12 months, Aggregate Loss1	(812)	(2,667)
Available-for-Sale, 12 Months or More Fair Value	61,120	82,690
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 months or Longer, Aggregate Loss1	(376)	(1,058)
Available-for-Sale, Total Fair Value	326,658	639,513
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss1	(1,188)	(3,725)
Held-to-Maturity:
Held-to-Maturity, Less than 12 Months Fair Value	27,229	128,350
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less Than 12 months, Aggregate Loss1	(4,432)	(4,649)
Held-to-Maturity, 12 Months or More Fair Value	27,655	79,015
Held-to-Maturity, 12 Months or More Gross Unrealized Losses	(788)	(1,320)
Held-to-Maturity, Total Fair Value	54,884	207,365
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss1	$ (5,220)	(5,969)
Available-for-Sale and Held-to-Maturity:
Investment Securities in an Unrealized Loss Position (Number of Securities) | securities	109
Obligations of U.S. government agencies
Available-for-Sale:
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 118,698	209,631
Available-for-sale Securities, Continuous Unrealized Loss Position, Less Than 12 months, Aggregate Loss1	(226)	(1,077)
Available-for-Sale, 12 Months or More Fair Value	35,355	54,619
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 months or Longer, Aggregate Loss1	(98)	(533)
Available-for-Sale, Total Fair Value	154,053	264,250
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss1	(324)	(1,610)
Held-to-Maturity:
Held-to-Maturity, Less than 12 Months Fair Value		19,738
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less Than 12 months, Aggregate Loss1		(102)
Held-to-Maturity, 12 Months or More Fair Value		0
Held-to-Maturity, 12 Months or More Gross Unrealized Losses		0
Held-to-Maturity, Total Fair Value		19,738
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss1		(102)
U.S. agency residential mortgage-backed securities & collateralized mortgage obligations
Available-for-Sale:
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	146,840	343,875
Available-for-sale Securities, Continuous Unrealized Loss Position, Less Than 12 months, Aggregate Loss1	(586)	(1,577)
Available-for-Sale, 12 Months or More Fair Value	25,708	28,010
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 months or Longer, Aggregate Loss1	(276)	(524)
Available-for-Sale, Total Fair Value	172,548	371,885
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss1	(862)	(2,101)
Held-to-Maturity:
Held-to-Maturity, Less than 12 Months Fair Value	13,801	67,295
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less Than 12 months, Aggregate Loss1	(4,364)	(4,288)
Held-to-Maturity, 12 Months or More Fair Value	24,049	69,539
Held-to-Maturity, 12 Months or More Gross Unrealized Losses	(781)	(1,132)
Held-to-Maturity, Total Fair Value	37,850	136,834
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss1	(5,145)	(5,420)
State, county and municipal securities
Held-to-Maturity:
Held-to-Maturity, Less than 12 Months Fair Value	3,379	10,182
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less Than 12 months, Aggregate Loss1	(7)	(39)
Held-to-Maturity, 12 Months or More Fair Value	3,606	9,476
Held-to-Maturity, 12 Months or More Gross Unrealized Losses	(7)	(188)
Held-to-Maturity, Total Fair Value	6,985	19,658
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss1	(14)	(227)
Private mortgage-backed securities
Available-for-Sale:
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Less Than 12 months, Aggregate Loss1	0	0
Available-for-Sale, 12 Months or More Fair Value	57	61
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 months or Longer, Aggregate Loss1	(2)	(1)
Available-for-Sale, Total Fair Value	57	61
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss1	(2)	(1)
Corporate securities
Held-to-Maturity:
Held-to-Maturity, Less than 12 Months Fair Value	10,049	31,135
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less Than 12 months, Aggregate Loss1	(61)	(220)
Held-to-Maturity, 12 Months or More Fair Value	0	0
Held-to-Maturity, 12 Months or More Gross Unrealized Losses	0	0
Held-to-Maturity, Total Fair Value	10,049	31,135
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss1	(61)	(220)
Other Investments
Available-for-Sale:
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	0	1,225
Available-for-sale Securities, Continuous Unrealized Loss Position, Less Than 12 months, Aggregate Loss1	0	(9)
Available-for-Sale, 12 Months or More Fair Value	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 months or Longer, Aggregate Loss1	0	0
Available-for-Sale, Total Fair Value	0	1,225
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss1	$ 0	$ (9)

Maturities of Investment Securi

Maturities of Investment Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity
Available-for-Sale Amortized Cost, Within One Year	$ 317,502
Available-for-Sale Amortized Cost, After One Year but Within Five Years	1,089,290
Available-for-Sale Amortized Cost, After Five Years but Within Ten Years	70,534
Available-for-Sale Amortized Cost, After Ten Years	70,891
Available-for-Sale, Amortized Cost	1,548,217	$ 1,450,396
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity
Available-for-Sale Estimated Fair Value, Within One Year	320,927
Available-for-Sale Estimated Fair Value, After One Year but Within Five Years	1,099,333
Available-for-Sale Estimated Fair Value, After Ten Years	71,242
Available-for-Sale Estimated Fair Value, After Five Years but Within Ten Years	71,848
Available-for-Sale, Estimated Fair Value	1,563,350	1,456,840
Held-to-maturity Securities, Debt Maturities, Net Carrying Amount
Held-to-Maturity Amortized Cost, Within One Year	87,930
Held-to-Maturity Amortized Cost, After One Year but Within Five Years	328,090
Held-to-Maturity Amortized Cost, After Five Years but Within Ten Years	125,412
Held-to-Maturity Amortized Cost, After Ten Years	39,958
Held-to-Maturity, Amortized Cost	581,390	600,665
Held-to-maturity Securities, Debt Maturities, Fair Value, Rolling Maturity
Held-to-Maturity Estimated Fair Value, Within One Year	90,154
Held-to-Maturity Estimated Fair Value, After One Year but Within Five Years	333,231
Held-to-Maturity Estimated Fair Value, After Five Years but Within Ten Years	128,977
Held-to-Maturity Estimated Fair Value, After Ten Years	41,542
Held-to-Maturity, Estimated Fair Value	593,904	$ 607,550
Callable Within One Year
Available-for-sale Securities and Held-to-maturity Securities
Investment Securities Primarily Classified as Available-for-Sale, Amortized Costs, After One Year but Within Five Years	277,491
Investment Securities Primarily Classified as Available-for-Sale, Fair Value, After One Year but Within Five Years	277,837
Callable Structured Notes
Available-for-sale Securities and Held-to-maturity Securities
Investment Securities Primarily Classified as Available-for-Sale, Amortized Costs, After One Year but Within Five Years	10,000
Investment Securities Primarily Classified as Available-for-Sale, Fair Value, After One Year but Within Five Years	$ 10,000

Schedule of Loans by Class (Det

Schedule of Loans by Class (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Loans and Leases Receivable [Line Items]
Loans held for investment	$ 5,191,469	$ 5,193,321
Mortgage loans held for sale	52,989	52,875
Total loans	5,244,458	5,246,196
Commercial real estate
Loans and Leases Receivable [Line Items]
Loans held for investment	1,764,492	1,793,258
Land acquisition & development construction real estate
Loans and Leases Receivable [Line Items]
Loans held for investment	219,450	224,066
Residential construction real estate
Loans and Leases Receivable [Line Items]
Loans held for investment	113,317	111,763
Commercial construction real estate
Loans and Leases Receivable [Line Items]
Loans held for investment	102,382	94,890
Total construction loans
Loans and Leases Receivable [Line Items]
Loans held for investment	435,149	430,719
Residential real estate
Loans and Leases Receivable [Line Items]
Loans held for investment	1,021,443	1,032,851
Agricultural real estate
Loans and Leases Receivable [Line Items]
Loans held for investment	153,054	156,234
Total real estate loans
Loans and Leases Receivable [Line Items]
Loans held for investment	3,374,138	3,413,062
Indirect consumer
Loans and Leases Receivable [Line Items]
Loans held for investment	651,057	622,529
Other consumer
Loans and Leases Receivable [Line Items]
Loans held for investment	150,774	153,717
Credit card consumer
Loans and Leases Receivable [Line Items]
Loans held for investment	63,624	68,107
Total consumer loans
Loans and Leases Receivable [Line Items]
Loans held for investment	865,455	844,353
Commercial
Loans and Leases Receivable [Line Items]
Loans held for investment	825,043	792,416
Agricultural
Loans and Leases Receivable [Line Items]
Loans held for investment	126,290	142,151
Other, including overdrafts
Loans and Leases Receivable [Line Items]
Loans held for investment	$ 543	$ 1,339

Loans Schedule of Loans Acquire

Loans Schedule of Loans Acquired from Business Combinations (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Jun. 30, 2014
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities [Abstract]
Outstanding Balance	$ 33,175	$ 32,445
Carrying Amount Net, Accrual Status	21,064	23,909
Carrying Amount Net, Non Accrual Status	0	0
Total Carrying Value	$ 21,064	$ 23,909

Loans Certain Loans Acquired in

Loans Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Beginning Balance	$ 6,713	$ 5,781
Accretion Income	(614)	(548)
Reductions Due to Exit Events	(147)	(396)
Reclassifications from (to) nonaccretable differences	726	2,143
Ending Balance	$ 6,678	$ 6,980

Schedule of Recorded Investment

Schedule of Recorded Investment in Past Due Loans by Class (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Mortgage loans held for sale	$ 52,989		$ 52,875
Loans held for investment	5,191,469		5,193,321
Total loans	5,244,458		5,246,196
Interest Income on Non-Accrual Loans if Accrued	790	$ 832
Commercial real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	5,282		7,193
Current Loans	1,736,374		1,762,294
Non-accrual Loans	22,836		23,771
Loans held for investment	1,764,492		1,793,258
Land acquisition & development construction real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	2,159		4,678
Current Loans	210,994		212,757
Non-accrual Loans	6,297		6,631
Loans held for investment	219,450		224,066
Residential construction real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	96		1,288
Current Loans	112,166		110,182
Non-accrual Loans	1,055		293
Loans held for investment	113,317		111,763
Commercial construction real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	184		3,232
Current Loans	101,915		90,703
Non-accrual Loans	283		955
Loans held for investment	102,382		94,890
Total construction loans
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	2,439		9,198
Current Loans	425,075		413,642
Non-accrual Loans	7,635		7,879
Loans held for investment	435,149		430,719
Residential real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	7,539		9,250
Current Loans	1,010,803		1,018,359
Non-accrual Loans	3,101		5,242
Loans held for investment	1,021,443		1,032,851
Agricultural real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	27		193
Current Loans	147,423		150,686
Non-accrual Loans	5,604		5,355
Loans held for investment	153,054		156,234
Total real estate loans
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	15,287		25,834
Current Loans	3,319,675		3,344,981
Non-accrual Loans	39,176		42,247
Loans held for investment	3,374,138		3,413,062
Indirect consumer
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	5,711		7,974
Current Loans	644,517		614,029
Non-accrual Loans	829		526
Loans held for investment	651,057		622,529
Other consumer
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	877		1,677
Current Loans	149,419		151,381
Non-accrual Loans	478		659
Loans held for investment	150,774		153,717
Credit card consumer
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	1,287		1,327
Current Loans	62,325		66,768
Non-accrual Loans	12		12
Loans held for investment	63,624		68,107
Total consumer loans
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	7,875		10,978
Current Loans	856,261		832,178
Non-accrual Loans	1,319		1,197
Loans held for investment	865,455		844,353
Commercial
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	3,139		10,252
Current Loans	799,325		759,851
Non-accrual Loans	22,579		22,313
Loans held for investment	825,043		792,416
Agricultural
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	2,745		1,093
Current Loans	122,782		140,430
Non-accrual Loans	763		628
Loans held for investment	126,290		142,151
Other, including overdrafts
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	317		314
Current Loans	226		1,025
Non-accrual Loans	0		0
Loans held for investment	543		1,339
Loans held for investment
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	29,363		48,471
Current Loans	5,098,269		5,078,465
Non-accrual Loans	63,837		66,385
Loans held for investment	5,191,469		5,193,321
Mortgage loans originated for sale
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	0		0
Current Loans	52,989		52,875
Non-accrual Loans	0		0
Total loans
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	29,363		48,471
Current Loans	5,151,258		5,131,340
Non-accrual Loans	63,837		66,385
Total loans	5,244,458		5,246,196
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	2,302		6,051
Financing Receivables, 30 to 59 Days Past Due [Member] | Land acquisition & development construction real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	951		3,190
Financing Receivables, 30 to 59 Days Past Due [Member] | Residential construction real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	96		1,288
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial construction real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	184		3,232
Financing Receivables, 30 to 59 Days Past Due [Member] | Total construction loans
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	1,231		7,710
Financing Receivables, 30 to 59 Days Past Due [Member] | Residential real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	4,804		5,991
Financing Receivables, 30 to 59 Days Past Due [Member] | Agricultural real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	27		176
Financing Receivables, 30 to 59 Days Past Due [Member] | Total real estate loans
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	8,364		19,928
Financing Receivables, 30 to 59 Days Past Due [Member] | Indirect consumer
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	4,448		6,675
Financing Receivables, 30 to 59 Days Past Due [Member] | Other consumer
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	613		1,312
Financing Receivables, 30 to 59 Days Past Due [Member] | Credit card consumer
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	412		533
Financing Receivables, 30 to 59 Days Past Due [Member] | Total consumer loans
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	5,473		8,520
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	2,144		8,493
Financing Receivables, 30 to 59 Days Past Due [Member] | Agricultural
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	1,972		879
Financing Receivables, 30 to 59 Days Past Due [Member] | Other, including overdrafts
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	0		0
Financing Receivables, 30 to 59 Days Past Due [Member] | Loans held for investment
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	17,953		37,820
Financing Receivables, 30 to 59 Days Past Due [Member] | Mortgage loans originated for sale
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	0		0
Financing Receivables, 30 to 59 Days Past Due [Member] | Total loans
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	17,953		37,820
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	2,975		724
Financing Receivables, 60 to 89 Days Past Due [Member] | Land acquisition & development construction real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	351		163
Financing Receivables, 60 to 89 Days Past Due [Member] | Residential construction real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	0		0
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial construction real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	0		0
Financing Receivables, 60 to 89 Days Past Due [Member] | Total construction loans
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	351		163
Financing Receivables, 60 to 89 Days Past Due [Member] | Residential real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	985		1,196
Financing Receivables, 60 to 89 Days Past Due [Member] | Agricultural real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	0		17
Financing Receivables, 60 to 89 Days Past Due [Member] | Total real estate loans
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	4,311		2,100
Financing Receivables, 60 to 89 Days Past Due [Member] | Indirect consumer
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	1,075		1,089
Financing Receivables, 60 to 89 Days Past Due [Member] | Other consumer
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	226		331
Financing Receivables, 60 to 89 Days Past Due [Member] | Credit card consumer
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	346		317
Financing Receivables, 60 to 89 Days Past Due [Member] | Total consumer loans
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	1,647		1,737
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	763		1,060
Financing Receivables, 60 to 89 Days Past Due [Member] | Agricultural
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	322		152
Financing Receivables, 60 to 89 Days Past Due [Member] | Other, including overdrafts
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	5		0
Financing Receivables, 60 to 89 Days Past Due [Member] | Loans held for investment
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	7,048		5,049
Financing Receivables, 60 to 89 Days Past Due [Member] | Mortgage loans originated for sale
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	0		0
Financing Receivables, 60 to 89 Days Past Due [Member] | Total loans
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	7,048		5,049
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	5		418
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Land acquisition & development construction real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	857		1,325
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Residential construction real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	0		0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial construction real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	0		0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Total construction loans
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	857		1,325
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Residential real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	1,750		2,063
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Agricultural real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	0		0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Total real estate loans
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	2,612		3,806
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Indirect consumer
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	188		210
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Other consumer
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	38		34
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Credit card consumer
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	529		477
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Total consumer loans
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	755		721
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	232		699
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Agricultural
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	451		62
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Other, including overdrafts
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	312		314
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Loans held for investment
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	4,362		5,602
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Mortgage loans originated for sale
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	0		0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Total loans
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	$ 4,362		$ 5,602

Loans Schedule of Recorded Inve

Loans Schedule of Recorded Investment in Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Impaired Financing Receivable, Unpaid Principal Balance
Unpaid Total Principal Balance	$ 114,871		$ 120,387
Recorded Investment With No Allowance	51,427		56,236
Recorded Investment With Allowance	37,217		35,729
Total Recorded Investment	88,644		91,965
Related Allowance	13,947		11,575
Impaired Financing Receivable, Average Recorded Investment and Cash Basis Method Interest Income
Average Recorded Investment	76,535	$ 84,599
Income Recognized	60	198
Interest Income on Impaired Loans If Interest Had Been Accrued	929	1,035
Commercial real estate
Impaired Financing Receivable, Unpaid Principal Balance
Unpaid Total Principal Balance	55,222		58,179
Recorded Investment With No Allowance	25,759		27,882
Recorded Investment With Allowance	18,117		17,614
Total Recorded Investment	43,876		45,496
Related Allowance	4,526		3,401
Impaired Financing Receivable, Average Recorded Investment and Cash Basis Method Interest Income
Average Recorded Investment	33,483	42,077
Income Recognized	36	150
Land acquisition & development construction real estate
Impaired Financing Receivable, Unpaid Principal Balance
Unpaid Total Principal Balance	15,252		15,503
Recorded Investment With No Allowance	7,742		7,245
Recorded Investment With Allowance	322		778
Total Recorded Investment	8,064		8,023
Related Allowance	150		282
Impaired Financing Receivable, Average Recorded Investment and Cash Basis Method Interest Income
Average Recorded Investment	7,508	8,930
Income Recognized	7	10
Residential construction real estate
Impaired Financing Receivable, Unpaid Principal Balance
Unpaid Total Principal Balance	988		992
Recorded Investment With No Allowance	282		293
Recorded Investment With Allowance	0		0
Total Recorded Investment	282		293
Related Allowance	0		0
Impaired Financing Receivable, Average Recorded Investment and Cash Basis Method Interest Income
Average Recorded Investment	288	308
Income Recognized	0	0
Commercial construction real estate
Impaired Financing Receivable, Unpaid Principal Balance
Unpaid Total Principal Balance	1,370		1,264
Recorded Investment With No Allowance	446		340
Recorded Investment With Allowance	731		739
Total Recorded Investment	1,177		1,079
Related Allowance	739		739
Impaired Financing Receivable, Average Recorded Investment and Cash Basis Method Interest Income
Average Recorded Investment	1,067	3,055
Income Recognized	0	2
Total construction loans
Impaired Financing Receivable, Unpaid Principal Balance
Unpaid Total Principal Balance	17,610		17,759
Recorded Investment With No Allowance	8,470		7,878
Recorded Investment With Allowance	1,053		1,517
Total Recorded Investment	9,523		9,395
Related Allowance	889		1,021
Impaired Financing Receivable, Average Recorded Investment and Cash Basis Method Interest Income
Average Recorded Investment	8,863	12,293
Income Recognized	7	12
Residential real estate
Impaired Financing Receivable, Unpaid Principal Balance
Unpaid Total Principal Balance	5,664		7,073
Recorded Investment With No Allowance	3,019		3,547
Recorded Investment With Allowance	1,152		2,317
Total Recorded Investment	4,171		5,864
Related Allowance	160		367
Impaired Financing Receivable, Average Recorded Investment and Cash Basis Method Interest Income
Average Recorded Investment	4,206	3,127
Income Recognized	1	1
Agricultural real estate
Impaired Financing Receivable, Unpaid Principal Balance
Unpaid Total Principal Balance	6,685		6,434
Recorded Investment With No Allowance	5,816		5,563
Recorded Investment With Allowance	201		198
Total Recorded Investment	6,017		5,761
Related Allowance	7		5
Impaired Financing Receivable, Average Recorded Investment and Cash Basis Method Interest Income
Average Recorded Investment	5,748	8,655
Income Recognized	1	22
Total real estate loans
Impaired Financing Receivable, Unpaid Principal Balance
Unpaid Total Principal Balance	85,181		89,445
Recorded Investment With No Allowance	43,064		44,870
Recorded Investment With Allowance	20,523		21,646
Total Recorded Investment	63,587		66,516
Related Allowance	5,582		4,794
Impaired Financing Receivable, Average Recorded Investment and Cash Basis Method Interest Income
Average Recorded Investment	52,300	66,152
Income Recognized	45	185
Commercial
Impaired Financing Receivable, Unpaid Principal Balance
Unpaid Total Principal Balance	28,782		29,593
Recorded Investment With No Allowance	8,113		10,744
Recorded Investment With Allowance	16,150		13,727
Total Recorded Investment	24,263		24,471
Related Allowance	8,176		6,487
Impaired Financing Receivable, Average Recorded Investment and Cash Basis Method Interest Income
Average Recorded Investment	23,379	17,533
Income Recognized	15	8
Agricultural
Impaired Financing Receivable, Unpaid Principal Balance
Unpaid Total Principal Balance	908		1,349
Recorded Investment With No Allowance	250		622
Recorded Investment With Allowance	544		356
Total Recorded Investment	794		978
Related Allowance	189		$ 294
Impaired Financing Receivable, Average Recorded Investment and Cash Basis Method Interest Income
Average Recorded Investment	856	914
Income Recognized	$ 0	$ 5

Schedule of Loans Renegotiated

Schedule of Loans Renegotiated in Troubled Debt Restructurings (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2016USD ($)notes	Mar. 31, 2015USD ($)	Dec. 31, 2015USD ($)
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Loans Renegotiated in Troubled Debt Restructurings	$ 34,344		$ 40,330
Loans Renegotiated in Troubled Debt Restructurings, Non-Accrual Loans	22,274		24,911
Loans Renegotiated in Troubled Debt Restructurings, Accrual Loans	$ 12,070		$ 15,419
Number of Notes | notes	3
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 780
Financing Receivables, Impaired, Troubled Debt Restructuring, Write-down	$ 0	$ 0
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | notes	1
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 203
Loans and Leases Receivable, Impaired, Commitment to Lend	0
Interest only period
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Pre-Modification Recorded Investment	576
Extension of terms or maturity
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 204
Commercial real estate
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | notes	1
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 203

Schedule of Recorded Investme45

Schedule of Recorded Investment in Criticized Loans by Class and Credit Quality Indicator (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	$ 5,191,469	$ 5,193,321
Commercial real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	1,764,492	1,793,258
Land acquisition & development construction real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	219,450	224,066
Residential construction real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	113,317	111,763
Commercial construction real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	102,382	94,890
Total construction loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	435,149	430,719
Residential real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	1,021,443	1,032,851
Agricultural real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	153,054	156,234
Total real estate loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	3,374,138	3,413,062
Indirect consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	651,057	622,529
Other consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	150,774	153,717
Credit card consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	63,624	68,107
Total consumer loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	865,455	844,353
Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	825,043	792,416
Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	126,290	142,151
Other Assets Especially Mentioned
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	144,993	127,270
Other Assets Especially Mentioned | Commercial real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	77,147	61,787
Other Assets Especially Mentioned | Land acquisition & development construction real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	11,854	16,593
Other Assets Especially Mentioned | Residential construction real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	2,003	1,640
Other Assets Especially Mentioned | Commercial construction real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	4,056	166
Other Assets Especially Mentioned | Total construction loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	17,913	18,399
Other Assets Especially Mentioned | Residential real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	5,681	4,453
Other Assets Especially Mentioned | Agricultural real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	7,519	6,114
Other Assets Especially Mentioned | Total real estate loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	108,260	90,753
Other Assets Especially Mentioned | Indirect consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	704	644
Other Assets Especially Mentioned | Other consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	1,024	651
Other Assets Especially Mentioned | Total consumer loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	1,728	1,295
Other Assets Especially Mentioned | Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	31,392	32,975
Other Assets Especially Mentioned | Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	3,613	2,247
Substandard
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	167,826	162,785
Substandard | Commercial real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	82,536	84,556
Substandard | Land acquisition & development construction real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	11,226	12,482
Substandard | Residential construction real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	389	1,886
Substandard | Commercial construction real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	429	323
Substandard | Total construction loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	12,044	14,691
Substandard | Residential real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	10,107	9,661
Substandard | Agricultural real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	18,920	16,529
Substandard | Total real estate loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	123,607	125,437
Substandard | Indirect consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	1,446	1,131
Substandard | Other consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	914	1,130
Substandard | Total consumer loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	2,360	2,261
Substandard | Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	34,039	27,982
Substandard | Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	7,820	7,105
Doubtful
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	34,578	30,350
Doubtful | Commercial real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	14,311	10,609
Doubtful | Land acquisition & development construction real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	1,515	591
Doubtful | Residential construction real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	0	0
Doubtful | Commercial construction real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	748	756
Doubtful | Total construction loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	2,263	1,347
Doubtful | Residential real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	477	2,540
Doubtful | Agricultural real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	0	0
Doubtful | Total real estate loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	17,051	14,496
Doubtful | Indirect consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	144	154
Doubtful | Other consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	211	198
Doubtful | Total consumer loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	355	352
Doubtful | Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	16,629	15,085
Doubtful | Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	543	417
Total Criticized Loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	347,397	320,405
Total Criticized Loans | Commercial real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	173,994	156,952
Total Criticized Loans | Land acquisition & development construction real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	24,595	29,666
Total Criticized Loans | Residential construction real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	2,392	3,526
Total Criticized Loans | Commercial construction real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	5,233	1,245
Total Criticized Loans | Total construction loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	32,220	34,437
Total Criticized Loans | Residential real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	16,265	16,654
Total Criticized Loans | Agricultural real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	26,439	22,643
Total Criticized Loans | Total real estate loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	248,918	230,686
Total Criticized Loans | Indirect consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	2,294	1,929
Total Criticized Loans | Other consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	2,149	1,979
Total Criticized Loans | Total consumer loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	4,443	3,908
Total Criticized Loans | Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	82,060	76,042
Total Criticized Loans | Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	$ 11,976	$ 9,769

Schedule of Allowance for Loan

Schedule of Allowance for Loan Losses by Portfolio Segment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2016	Dec. 31, 2015
Financing Receivable, Allowance for Credit Losses [Line Items]
Certain Loans and Debt Securities Acquired in Transfer, Allowance for Credit Losses Due to Subsequent Impairment			$ 393	$ 287
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	$ 76,817	$ 74,200
Provision charged to operating expense	4,000	1,095
Less loans charged-off	(4,302)	(1,861)
Add back recoveries of loans previously charged-off	3,409	1,902
Ending balance	79,924	75,336
Allowance for loan losses:
Loans individually evaluated for impairment			13,947	11,575
Loans collectively evaluated for impairment			65,977	65,242
Ending balance	76,817	74,200	79,924	76,817
Total loans:
Individually evaluated for impairment			88,644	91,965
Individually evaluated for impairment			5,102,825	5,101,356
Total loans			5,191,469	5,193,321
Real Estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	52,296	53,884
Provision charged to operating expense	(16,081)	(1,031)
Less loans charged-off	(1,922)	(186)
Add back recoveries of loans previously charged-off	2,359	992
Ending balance	36,652	53,659
Allowance for loan losses:
Loans individually evaluated for impairment			5,582	4,794
Loans collectively evaluated for impairment			31,070	47,502
Ending balance	52,296	53,884	36,652	52,296
Total loans:
Individually evaluated for impairment			63,587	66,516
Individually evaluated for impairment			3,310,551	3,346,546
Total loans			3,374,138	3,413,062
Total consumer loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	5,144	5,035
Provision charged to operating expense	1,229	1,125
Less loans charged-off	(1,892)	(1,301)
Add back recoveries of loans previously charged-off	775	640
Ending balance	5,256	5,499
Allowance for loan losses:
Loans individually evaluated for impairment			0	0
Loans collectively evaluated for impairment			5,256	5,144
Ending balance	5,144	5,035	5,256	5,144
Total loans:
Individually evaluated for impairment			0	0
Individually evaluated for impairment			865,455	844,353
Total loans			865,455	844,353
Commercial
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	18,775	14,307
Provision charged to operating expense	17,690	993
Less loans charged-off	(488)	(374)
Add back recoveries of loans previously charged-off	275	270
Ending balance	36,252	15,196
Allowance for loan losses:
Loans individually evaluated for impairment			8,176	6,487
Loans collectively evaluated for impairment			28,076	12,288
Ending balance	18,775	14,307	36,252	18,775
Total loans:
Individually evaluated for impairment			24,263	24,471
Individually evaluated for impairment			800,780	767,945
Total loans			825,043	792,416
Agriculture
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	602	974
Provision charged to operating expense	1,162	8
Less loans charged-off	0	0
Add back recoveries of loans previously charged-off	0	0
Ending balance	1,764	982
Allowance for loan losses:
Loans individually evaluated for impairment			189	294
Loans collectively evaluated for impairment			1,575	308
Ending balance	602	974	1,764	602
Total loans:
Individually evaluated for impairment			794	978
Individually evaluated for impairment			125,496	141,173
Total loans			126,290	142,151
Other
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	0	0
Provision charged to operating expense	0	0
Less loans charged-off	0	0
Add back recoveries of loans previously charged-off	0	0
Ending balance	0	0
Allowance for loan losses:
Loans individually evaluated for impairment			0	0
Loans collectively evaluated for impairment			0	0
Ending balance	$ 0	$ 0	0	0
Total loans:
Individually evaluated for impairment			0	0
Individually evaluated for impairment			543	1,339
Total loans			$ 543	$ 1,339

OREO (Details)

OREO (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Mortgage Loans in Process of Foreclosure, Amount	$ 0
Real Estate Acquired Through Foreclosure [Roll Forward]
Beginning balance	6,254	$ 13,554
Additions	3,227	3,257
Valuation adjustments	(17)	(106)
Dispositions	(207)	(1,571)
Ending balance	9,257	$ 15,134
Residential real estate
Real Estate Acquired Through Foreclosure [Roll Forward]
Beginning balance	1,686
Ending balance	$ 4,087

Derivatives and Hedging (Detail

Derivatives and Hedging (Details) - USD ($) $ in Thousands	Sep. 22, 2015	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Derivative [Line Items]
Derivative, Inception Date	Sep. 22, 2015
Derivative Liability, Notional Amount	$ 100,000	$ 186,610		$ 9,369
Interest Rate Derivative Liabilities, at Fair Value		3,619		829
Derivative Asset, Notional Amount		121,986		109,369
Interest Rate Derivative Assets, at Fair Value		2,138		953
Derivative, Fixed Interest Rate	1.94%
Interest Rate Swap [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount				100,000
Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative Instruments, Loss Recognized in Other Comprehensive Income (Loss), Effective Portion		(2,197)	$ 0
Derivative Liability, Notional Amount		100,000		0
Interest Rate Derivative Liabilities, at Fair Value		2,032		0
Derivative Asset, Notional Amount		0		100,000
Interest Rate Derivative Assets, at Fair Value		0		165
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount		9,281		9,369
Interest Rate Derivative Liabilities, at Fair Value		1,173		829
Derivative Asset, Notional Amount		9,281		9,369
Interest Rate Derivative Assets, at Fair Value		1,102		788
Derivative, Loss on Derivative		(29)	(7)
Not Designated as Hedging Instrument [Member] | Interest Rate Lock Commitments [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount		112,705		0
Interest Rate Derivative Assets, at Fair Value		1,036		0
Not Designated as Hedging Instrument [Member] | Forward Contracts [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount		77,329		0
Interest Rate Derivative Liabilities, at Fair Value		414		$ 0
Derivative, Loss on Derivative		$ (695)	$ 0

Capital Stock (Details)

Capital Stock (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Class of Stock [Line Items]
Payments for Repurchase of Common Stock	$ 25,309	$ 15,264
Class A Common Stock
Class of Stock [Line Items]
Common Stock, Shares, Outstanding	21,007,483		21,698,594
Stock Repurchased and Retired During Period, Shares	948,242	565,875
Payments for Repurchase of Common Stock	$ 24,792	$ 14,674
Stock Repurchase Program, Remaining Authorized Repurchase Amount	51,758
Class B Common Stock
Class of Stock [Line Items]
Common Stock, Shares, Outstanding	23,700,002		23,729,631

Computation of Basic and Dilute

Computation of Basic and Diluted Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Net Income (Loss) Available to Common Stockholders, Basic
Net income	$ 20,124	$ 20,980
Weighted Average Number of Shares Outstanding, Basic and Diluted
Weighted average common shares outstanding for basic earnings per share computation	44,719,218	45,378,230
Dilutive effect of stock-based compensation	394,834	461,961
Weighted average common shares outstanding for diluted earnings per common share computation	45,114,052	45,840,191
Earnings Per Share, Basic and Diluted
Basic earnings per common share	$ 0.45	$ 0.46
Diluted earnings per common share	$ 0.45	$ 0.46
Performance Shares [Member]
Earnings Per Share, Basic and Diluted [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	226,821	166,770
Stock Options
Earnings Per Share, Basic and Diluted [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0	5,000
Unvested Restricted Stock
Earnings Per Share, Basic and Diluted [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	40,865

Schedule of Actual Capital Amou

Schedule of Actual Capital Amounts and Ratios and Selected Minimum Regulatory Thresholds (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Total risk-based capital:
Actual Amount	$ 930,048	$ 946,156
Actual Ratio	15.00%	15.40%
Well Capitalized Amount	$ 618,456	$ 615,865
Well Capitalized Ratio	10.00%	10.00%
Tier 1 risk-based capital:
Actual Amount	$ 848,709	$ 861,339
Actual Ratio	13.70%	14.00%
Well Capitalized Amount	$ 494,765	$ 492,692
Well Capitalized Ratio	8.00%	8.00%
Common equity tier one risk-based capital:
Actual Amount	$ 768,709	$ 781,339
Actual Ratio	12.40%	12.70%
Leverage capital ratio:
Actual Amount	$ 848,709	$ 861,339
Actual Ratio	10.10%	10.10%
Adequately Capitalized Amount	$ 337,137	$ 340,480
Adequately Capitalized Ratio	4.00%	4.00%
Well Capitalized Amount	$ 421,421	$ 425,600
Well Capitalized Ratio	5.00%	5.00%
Capital Required for Capital Adequacy under Basel III Phase-in Schedule	$ 533,419	$ 492,692
Capital Required for Capital Adequacy under Basel III Phase-in Schedule to Risk Weighted Assets	8.60%	8.00%
Capital Required for Capital Adequacy under Basel III Fully Phased-in	$ 649,379	$ 646,658
Capital Required for Capital Adequacy under Basel III Fully Phased-in to Risk Weighted Assets	10.50%	10.50%
Tier One Risk Based Capital under Basel III Phase-in Schedule	$ 409,727	$ 369,519
Tier One Capital Required for Capital Adequacy under Basel III Phase-in Schedule to Risk Weighted Assets	6.60%	6.00%
Tier One Capital Required for Capital Adequacy under Basel III Fully Phased-in	$ 525,688	$ 523,485
Tier One Capital Required for Capital Adequacy under Basel III Fully Phased-in to Risk Weighted Assets	8.50%	8.50%
Common Equity Tier One Capital Required for Capital Adequacy under Basel III Phase-in Schedule	$ 316,959	$ 277,139
Common Equity Tier One Capital Required for Capital Adequacy under Basel III Phase-in Schedule to Risk Weighted Assets	5.10%	4.50%
Tier One Common Equity Capital Required for Capital Adequacy under Basel III Fully Phased-in	$ 432,919	$ 431,105
Tier One Common Equity Capital Required for Capital Adequacy under Basel III Fully Phased-in to Risk Weighted Assets	7.00%	7.00%
Common Equity Tier One Capital to be Well Capitalized	$ 401,997	$ 400,312
Common Equity Tier One Capital to be Well Capitalized to Risk Weighted Assets	6.50%	6.50%
FIB
Total risk-based capital:
Actual Amount	$ 876,265	$ 882,504
Actual Ratio	14.20%	14.40%
Well Capitalized Amount	$ 616,224	$ 613,582
Well Capitalized Ratio	10.00%	10.00%
Tier 1 risk-based capital:
Actual Amount	$ 799,201	$ 805,805
Actual Ratio	13.00%	13.10%
Well Capitalized Amount	$ 492,979	$ 490,866
Well Capitalized Ratio	8.00%	8.00%
Common equity tier one risk-based capital:
Actual Amount	$ 799,201	$ 805,805
Actual Ratio	13.00%	13.10%
Leverage capital ratio:
Actual Amount	$ 799,201	$ 805,805
Actual Ratio	9.50%	9.50%
Adequately Capitalized Amount	$ 336,258	$ 339,316
Adequately Capitalized Ratio	4.00%	4.00%
Well Capitalized Amount	$ 420,322	$ 424,145
Well Capitalized Ratio	5.00%	5.00%
Capital Required for Capital Adequacy under Basel III Phase-in Schedule	$ 531,493	$ 490,866
Capital Required for Capital Adequacy under Basel III Phase-in Schedule to Risk Weighted Assets	8.60%	8.00%
Capital Required for Capital Adequacy under Basel III Fully Phased-in	$ 647,035	$ 644,262
Capital Required for Capital Adequacy under Basel III Fully Phased-in to Risk Weighted Assets	10.50%	10.50%
Tier One Risk Based Capital under Basel III Phase-in Schedule	$ 408,248	$ 368,149
Tier One Capital Required for Capital Adequacy under Basel III Phase-in Schedule to Risk Weighted Assets	6.60%	6.00%
Tier One Capital Required for Capital Adequacy under Basel III Fully Phased-in	$ 523,790	$ 521,545
Tier One Capital Required for Capital Adequacy under Basel III Fully Phased-in to Risk Weighted Assets	8.50%	8.50%
Common Equity Tier One Capital Required for Capital Adequacy under Basel III Phase-in Schedule	$ 315,815	$ 276,112
Common Equity Tier One Capital Required for Capital Adequacy under Basel III Phase-in Schedule to Risk Weighted Assets	5.10%	4.50%
Tier One Common Equity Capital Required for Capital Adequacy under Basel III Fully Phased-in	$ 431,357	$ 429,508
Tier One Common Equity Capital Required for Capital Adequacy under Basel III Fully Phased-in to Risk Weighted Assets	7.00%	7.00%
Common Equity Tier One Capital to be Well Capitalized	$ 400,546	$ 398,829
Common Equity Tier One Capital to be Well Capitalized to Risk Weighted Assets	6.50%	6.50%

Commitments and Contingencies D

Commitments and Contingencies Derivatives (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Sep. 22, 2015
Derivative [Line Items]
Derivative Liability, Notional Amount	$ 186,610	$ 9,369	$ 100,000
Interest Rate Swap [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount		$ 100,000

Commitments and Contingencies L

Commitments and Contingencies Loans sold with recourse (Details)	3 Months Ended
	Mar. 31, 2016
Mortgage loans originated for sale
Loans and Leases Receivable [Line Items]
Guarantor Obligations, Recourse Provisions	3,465

Financial Instruments with Of54

Financial Instruments with Off-Balance Sheet Risk (Details) $ in Thousands	Mar. 31, 2016USD ($)
Entity Information [Line Items]
Credit Extension Commitments	$ 1,582,107
Credit Extension Commitments, Beyond One Year	400,922
Standby Letters of Credit
Entity Information [Line Items]
Credit Extension Commitments	52,402
Unused Credit Card Lines
Entity Information [Line Items]
Credit Extension Commitments	$ 562,367

Schedule of Comprehensive Incom

Schedule of Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Change in net unrealized Gain during period:
Change in net unrealized gain during period, before tax amount	$ 8,613	$ 10,608
Change in net unrealized gain during period, tax expense (benefit)	3,360	4,174
Change in net unrealized gain during period, net of tax amount	5,253	6,434
Reclassification adjustment for gains included in net income:
Reclassification adjustment for gains included in net income, before tax amount	21	(6)
Reclassification adjustment for gains included in net income, tax expense (benefit)	8	(2)
Reclassification adjustment for gains included in net income, net of tax amount	13	(4)
Change in unamortized loss on available-for-sale securities transferred into held-to-maturity	465	451
Other Comprehensive Income (Loss), Transfers from Held-to-maturity to Available-for-Sale Securities, Tax	183	177
Change in unamortized loss on available-for-sale securities transferred into held-to-maturity	282	274
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax	(2,197)	0
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	(835)	0
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(1,362)	0
Change in net actuarial loss:
Change in net actuarial loss, before tax amount	15	15
Change in net actuarial loss, tax expense (benefit)	6	6
Change in net actuarial loss, net of tax amount	9	9
Other comprehensive income (loss):
Other comprehensive income (loss), before tax	6,917	11,068
Total other comprehensive income, tax expense (benefit)	2,722	4,355
Total other comprehensive income, net of tax amount	$ 4,195	$ 6,713

Schedule of Accumulated Other C

Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Net accumulated other comprehensive income:
Net unrealized gain on investment securities available-for-sale	$ 6,232	$ 684
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	(1,262)	100
Net actuarial loss on defined benefit post-retirement benefit plans	(369)	(378)
Net accumulated other comprehensive income	$ 4,601	$ 406

Schedule of Financial Assets an

Schedule of Financial Assets and Financial Liabilities Measured at Fair Value on a Recurring and Non-Recurring Basis (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Real Estate Acquired Through Foreclosure, Valuation Adjustments	$ 17	$ 106
Related Allowance	13,947		$ 11,575
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgages Held-for-sale, Fair Value Disclosure	0
Deferred compensation asset at fair value amount	0
Deferred compensation plan liabilities at fair value amount	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value Measured on a Non-recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0		0
Other real estate owned	0		0
Long-lived assets to be disposed of by sale	0		0
Significant Other Observable Inputs (Level 2) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgages Held-for-sale, Fair Value Disclosure	52,989
Deferred compensation asset at fair value amount	9,566
Deferred compensation plan liabilities at fair value amount	9,566
Significant Other Observable Inputs (Level 2) | Fair Value Measured on a Non-recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0		0
Other real estate owned	0		0
Long-lived assets to be disposed of by sale	0		0
Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgages Held-for-sale, Fair Value Disclosure	0
Deferred compensation asset at fair value amount	0
Deferred compensation plan liabilities at fair value amount	0
Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Non-recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	19,363		20,875
Other real estate owned	3,464		1,789
Real Estate Acquired Through Foreclosure, Valuation Adjustments	17
Impairment of real estate, received updated appraisal	11
Impairment of Real Estate, Change in Management Estimates	6	$ 106
Long-lived assets to be disposed of by sale	1,506		1,506
Related Allowance	13,946		11,575
Impaired Financing Receivable, Related Allowance, Partial Loan Charge-Offs	9,391		10,229
US Treasury Securities [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0		0
US Treasury Securities [Member] | Significant Other Observable Inputs (Level 2) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	3,935		3,911
US Treasury Securities [Member] | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0		0
Obligations of U.S. government agencies | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0		0
Obligations of U.S. government agencies | Significant Other Observable Inputs (Level 2) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	531,432		520,181
Obligations of U.S. government agencies | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0		0
U.S. agency residential mortgage-backed securities & collateralized mortgage obligations | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0		0
U.S. agency residential mortgage-backed securities & collateralized mortgage obligations | Significant Other Observable Inputs (Level 2) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	1,024,363		929,046
U.S. agency residential mortgage-backed securities & collateralized mortgage obligations | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0		0
Private mortgage-backed securities | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0		0
Private mortgage-backed securities | Significant Other Observable Inputs (Level 2) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	143		156
Private mortgage-backed securities | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0		0
Other Investments | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0
Other Investments | Significant Other Observable Inputs (Level 2) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	3,477
Other Investments | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0
Estimated Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	1,563,350		1,456,840
Derivative Asset	2,138		953
Derivative Liability	3,619		829
Deferred compensation asset at fair value amount	9,566		10,149
Deferred compensation plan liabilities at fair value amount	9,566		10,149
Estimated Fair Value | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgages Held-for-sale, Fair Value Disclosure	52,989
Deferred compensation asset at fair value amount	9,566
Deferred compensation plan liabilities at fair value amount	9,566
Estimated Fair Value | Fair Value Measured on a Non-recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	19,363		20,875
Other real estate owned	3,464		1,789
Long-lived assets to be disposed of by sale	1,506		1,506
Estimated Fair Value | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0		0
Derivative Asset	0		0
Derivative Liability	0		0
Deferred compensation asset at fair value amount	0		0
Deferred compensation plan liabilities at fair value amount	0		0
Estimated Fair Value | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	1,563,350		1,456,840
Derivative Asset	2,138		953
Derivative Liability	3,619		829
Deferred compensation asset at fair value amount	9,566		10,149
Deferred compensation plan liabilities at fair value amount	9,566		10,149
Estimated Fair Value | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	0		0
Derivative Asset	0		0
Derivative Liability	0		0
Deferred compensation asset at fair value amount	0		0
Deferred compensation plan liabilities at fair value amount	0		0
Estimated Fair Value | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Non-recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	19,363		20,875
Estimated Fair Value | US Treasury Securities [Member] | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	3,935		3,911
Estimated Fair Value | Obligations of U.S. government agencies | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	531,432		520,181
Estimated Fair Value | U.S. agency residential mortgage-backed securities & collateralized mortgage obligations | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	1,024,363		929,046
Estimated Fair Value | Private mortgage-backed securities | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	143		156
Estimated Fair Value | Other Investments | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	3,477
Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	1,563,350		1,456,840
Derivative Asset	2,138		953
Derivative Liability	3,619		829
Deferred compensation asset at fair value amount	9,566		10,149
Deferred compensation plan liabilities at fair value amount	9,566		10,149
Carrying Amount | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Non-recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	42,700		42,679
Long-lived assets to be disposed of by sale	2,363		2,363
Change During Period | Fair Value Measured on a Non-recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-lived assets to be disposed of by sale	857		857
Interest Rate Swap [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	0		0
Derivative Liability	0		0
Interest Rate Swap [Member] | Significant Other Observable Inputs (Level 2) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	1,102		953
Derivative Liability	3,205		829
Interest Rate Swap [Member] | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	0		0
Derivative Liability	0		0
Interest Rate Swap [Member] | Estimated Fair Value | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	1,102		953
Derivative Liability	3,205		$ 829
Interest Rate Lock Commitments [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	0
Interest Rate Lock Commitments [Member] | Significant Other Observable Inputs (Level 2) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	1,036
Interest Rate Lock Commitments [Member] | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	0
Interest Rate Lock Commitments [Member] | Estimated Fair Value | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	1,036
Forward Contracts [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability	0
Forward Contracts [Member] | Significant Other Observable Inputs (Level 2) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability	414
Forward Contracts [Member] | Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability	0
Forward Contracts [Member] | Estimated Fair Value | Fair Value Measured on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability	$ 414

Fair Value Measurements Fair Va

Fair Value Measurements Fair Value Inputs, Quantitative Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Loans and Leases Receivable, Impaired Loans | Minimum | Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	(0.00%)
Loans and Leases Receivable, Impaired Loans | Maximum | Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	(53.00%)
Loans and Leases Receivable, Impaired Loans | Weighted Average | Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	(38.00%)
Real Estate Acquired in Satisfaction of Debt | Minimum | Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	(2.00%)
Real Estate Acquired in Satisfaction of Debt | Maximum | Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	(96.00%)
Real Estate Acquired in Satisfaction of Debt | Weighted Average | Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	(19.00%)
Asses to be Disposed of by Sale | Minimum | Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	(0.00%)
Asses to be Disposed of by Sale | Maximum | Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	(9.00%)
Asses to be Disposed of by Sale | Weighted Average | Market Approach Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	(6.00%)
Change During Period | Fair Value Measured on a Non-recurring Basis
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Long-lived assets to be disposed of by sale	$ 857	$ 857
Estimated Fair Value | Fair Value Measured on a Non-recurring Basis
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired loans	19,363	20,875
Long-lived assets to be disposed of by sale	1,506	1,506
Other real estate owned	3,464	1,789
Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Non-recurring Basis
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired loans	19,363	20,875
Long-lived assets to be disposed of by sale	1,506	1,506
Other real estate owned	3,464	1,789
Significant Unobservable Inputs (Level 3) | Carrying Amount | Fair Value Measured on a Non-recurring Basis
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired loans	42,700	42,679
Long-lived assets to be disposed of by sale	2,363	2,363
Significant Unobservable Inputs (Level 3) | Estimated Fair Value | Fair Value Measured on a Non-recurring Basis
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired loans	$ 19,363	$ 20,875

Schedule of Estimated Fair Valu

Schedule of Estimated Fair Values of Financial Instruments by Level of Valuation Inputs (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Financial assets:
Investment securities held-to-maturity	$ 593,904	$ 607,550
Carrying Amount
Financial assets:
Cash and cash equivalents	655,528	780,457
Investment securities available-for-sale	1,563,350	1,456,840
Investment securities held-to-maturity	581,390	600,665
Accrued interest receivable	26,907	27,729
Mortgage servicing rights	15,574	15,621
Net loans	5,164,534	5,169,379
Derivative Asset	2,138	953
Deferred compensation asset at fair value amount	9,566	10,149
Total financial assets	8,018,987	8,061,793
Financial liabilities:
Total deposits, excluding time deposits	6,004,127	5,957,345
Time deposits	1,103,336	1,131,592
Securities sold under repurchase agreements	465,523	510,635
Other borrowed funds	33	2
Derivative Liability	3,619	829
Deferred compensation plan liabilities at fair value amount	9,566	10,149
Accrued interest payable	5,184	4,960
Long-term debt	27,907	27,885
Subordinated debentures held by subsidiary trusts	82,477	82,477
Total financial liabilities	7,701,772	7,725,874
Estimated Fair Value
Financial assets:
Cash and cash equivalents	655,528	780,457
Investment securities available-for-sale	1,563,350	1,456,840
Investment securities held-to-maturity	593,904	607,550
Accrued interest receivable	26,907	27,729
Mortgage servicing rights	26,359	31,011
Net loans	5,105,350	5,128,705
Derivative Asset	2,138	953
Deferred compensation asset at fair value amount	9,566	10,149
Total financial assets	7,983,102	8,043,394
Financial liabilities:
Total deposits, excluding time deposits	6,004,127	5,975,345
Time deposits	1,100,852	1,137,289
Securities sold under repurchase agreements	465,523	510,635
Other borrowed funds	33	2
Derivative Liability	3,619	829
Deferred compensation plan liabilities at fair value amount	9,566	10,149
Accrued interest payable	5,184	4,960
Long-term debt	27,662	27,622
Subordinated debentures held by subsidiary trusts	72,252	74,969
Total financial liabilities	7,688,818	7,741,800
Quoted Prices in Active Markets for Identical Assets (Level 1) | Estimated Fair Value
Financial assets:
Cash and cash equivalents	655,528	780,457
Investment securities available-for-sale	0	0
Investment securities held-to-maturity	0	0
Accrued interest receivable	0	0
Mortgage servicing rights	0	0
Net loans	0	0
Derivative Asset	0	0
Deferred compensation asset at fair value amount	0	0
Total financial assets	655,528	780,457
Financial liabilities:
Total deposits, excluding time deposits	6,004,127	5,975,345
Time deposits	0	0
Securities sold under repurchase agreements	0	0
Other borrowed funds	0	0
Derivative Liability	0	0
Deferred compensation plan liabilities at fair value amount	0	0
Accrued interest payable	0	0
Long-term debt	0	0
Subordinated debentures held by subsidiary trusts	0	0
Total financial liabilities	6,004,127	5,975,345
Significant Other Observable Inputs (Level 2) | Estimated Fair Value
Financial assets:
Cash and cash equivalents	0	0
Investment securities available-for-sale	1,563,350	1,456,840
Investment securities held-to-maturity	593,904	607,550
Accrued interest receivable	26,907	27,729
Mortgage servicing rights	26,359	31,011
Net loans	5,085,987	5,107,830
Derivative Asset	2,138	953
Deferred compensation asset at fair value amount	9,566	10,149
Total financial assets	7,308,211	7,242,062
Financial liabilities:
Total deposits, excluding time deposits	0	0
Time deposits	1,100,852	1,137,289
Securities sold under repurchase agreements	465,523	510,635
Other borrowed funds	33	2
Derivative Liability	3,619	829
Deferred compensation plan liabilities at fair value amount	9,566	10,149
Accrued interest payable	5,184	4,960
Long-term debt	27,662	27,622
Subordinated debentures held by subsidiary trusts	72,252	74,969
Total financial liabilities	1,684,691	1,766,455
Significant Unobservable Inputs (Level 3) | Estimated Fair Value
Financial assets:
Cash and cash equivalents	0	0
Investment securities available-for-sale	0	0
Investment securities held-to-maturity	0	0
Accrued interest receivable	0	0
Mortgage servicing rights	0	0
Net loans	19,363	20,875
Derivative Asset	0	0
Deferred compensation asset at fair value amount	0	0
Total financial assets	19,363	20,875
Financial liabilities:
Total deposits, excluding time deposits	0	0
Time deposits	0	0
Securities sold under repurchase agreements	0	0
Other borrowed funds	0	0
Derivative Liability	0	0
Deferred compensation plan liabilities at fair value amount	0	0
Accrued interest payable	0	0
Long-term debt	0	0
Subordinated debentures held by subsidiary trusts	0	0
Total financial liabilities	$ 0	$ 0

Subsequent Events (Details)

Subsequent Events (Details) - $ / shares	May. 13, 2016	May. 02, 2016	Apr. 18, 2016	Jul. 24, 2015
Class A Common Stock | Subsequent Event [Member]
Subsequent Event [Line Items]
Dividends Payable, Date Declared			Apr. 18, 2016
Dividends Payable, Amount Per Share	$ 0.22
Dividends Payable, Date to be Paid	May 13, 2016
Dividends Payable, Date of Record		May 2, 2016
United Bank [Member]
Subsequent Event [Line Items]
Business Acquisition, Effective Date of Acquisition				Jul. 24, 2015