First Interstate BancSystem (FIBK) 10-Q 9 Aug 17 2017 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information	6 Months Ended
	Jun. 30, 2017shares
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	Jun. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q2
Amendment Flag	false
Class A Common Stock
Entity Common Stock, Shares Outstanding	33,260,710
Class B Common Stock
Entity Common Stock, Shares Outstanding	23,184,557

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Assets
Cash and due from banks	$ 223,880	$ 146,779
Federal funds sold	419	95
Interest bearing deposits in banks	695,476	635,149
Total cash and cash equivalents	919,775	782,023
Investment securities:
Available-for-sale	2,080,194	1,611,698
Held-to-maturity (estimated fair values of $535,145 and $513,273 at June 30, 2017 and December 31, 2016, respectively)	529,442	512,770
Total investment securities	2,609,636	2,124,468
Loans held for investment	7,525,590	5,416,750
Mortgage loans held for sale	30,383	61,794
Total loans	7,555,973	5,478,544
Less allowance for loan losses	75,701	76,214
Net loans	7,480,272	5,402,330
Goodwill	444,327	212,820
Premises and equipment, net of accumulated depreciation	243,152	194,457
Company-owned life insurance	257,538	198,116
Other real estate owned (OREO)	11,286	10,019
Deferred tax asset, net	9,406	0
Accrued interest receivable	35,830	29,852
Core deposit intangibles, net of accumulated amortization	52,837	9,648
Mortgage servicing rights, net of accumulated amortization and impairment reserve	23,715	18,457
Other assets	148,568	81,705
Total assets	12,236,342	9,063,895
Deposits:
Non-interest bearing	2,897,813	1,906,257
Interest bearing	7,122,187	5,469,853
Total deposits	10,020,000	7,376,110
Securities sold under repurchase agreements	579,772	537,556
Accounts payable and accrued expenses	96,762	44,923
Accrued interest payable	8,917	5,421
Deferred tax liability	0	6,839
Long-term debt	28,017	27,970
Other borrowed funds	15,019	6
Subordinated debentures held by subsidiary trusts	82,477	82,477
Total liabilities	10,830,964	8,081,302
Stockholders' equity:
Nonvoting noncumulative preferred stock without par value; authorized 100,000 shares; no shares issued and outstanding as of June 30, 2017 or December 31, 2016	0	0
Common stock	685,289	296,071
Retained earnings	718,093	694,650
Accumulated other comprehensive income, net	1,996	(8,128)
Total stockholders' equity	1,405,378	982,593
Total liabilities and stockholders' equity	$ 12,236,342	$ 9,063,895

Consolidated Balance Sheets (U3

Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Investment securities:
Held-to-Maturity, Estimated Fair Value	$ 535,145	$ 513,273
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		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Interest income:
Interest and fees on loans	$ 73,895	$ 62,634	$ 137,624	$ 125,450
Interest and dividends on investment securities:
Taxable	9,783	7,982	18,505	16,020
Exempt from federal taxes	855	858	1,647	1,737
Interest on deposits in banks	1,333	482	2,545	1,127
Interest on federal funds sold	3	3	5	5
Total interest income	85,869	71,959	160,326	144,339
Interest expense:
Interest on deposits	5,011	3,108	9,129	6,336
Interest on securities sold under repurchase agreements	272	92	520	182
Interest on long-term debt	481	451	934	900
Interest on subordinated debentures held by subsidiary trusts	782	675	1,527	1,338
Total interest expense	6,546	4,326	12,110	8,756
Net interest income	79,323	67,633	148,216	135,583
Provision for loan losses	2,355	2,550	4,085	6,550
Net interest income after provision for loan losses	76,968	65,083	144,131	129,033
Non-interest income:
Payment services revenues	10,225	8,648	18,670	16,639
Income from the origination and sale of loans	7,643	9,409	14,191	15,550
Investment Advisory, Management and Administrative Fees	5,084	5,166	10,097	9,741
Service charges on deposit accounts	5,060	4,626	9,410	9,089
Other service charges, commissions and fees	3,358	2,845	6,034	5,453
Investment securities gains, net	5	108	7	87
Other income	5,805	2,457	7,878	4,750
Non-recurring litigation recovery	0	3,750	0	3,750
Total non-interest income	37,180	37,009	66,287	65,059
Non-interest expense:
Salaries and wages	28,037	26,707	53,778	51,389
Employee benefits	9,811	8,066	19,427	17,675
Outsourced technology services	6,000	4,800	11,300	9,632
Occupancy, net	5,180	4,284	9,969	8,948
Furniture and equipment	2,739	2,460	5,012	4,716
OREO expense, net of income	34	140	(14)	101
Professional fees	1,795	1,136	2,824	2,444
FDIC insurance premiums	786	1,198	1,661	2,456
Mortgage servicing rights amortization	707	722	1,319	1,356
Mortgage servicing rights impairment recovery	(2)	(20)	(72)	(5)
Core deposit intangibles amortization	1,062	827	1,692	1,654
Other expenses	14,117	12,575	26,358	24,198
Non-core acquisition expenses	10,133	0	10,838	0
Total non-interest expense	80,399	62,895	144,092	124,564
Income before income tax expense	33,749	39,197	66,326	69,528
Income tax expense	11,881	13,643	21,332	23,850
Net income	$ 21,868	$ 25,554	$ 44,994	$ 45,678
Basic earnings per common share	$ 0.46	$ 0.58	$ 0.97	$ 1.03
Diluted earnings per common share	$ 0.45	$ 0.57	$ 0.96	$ 1.02

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Net income	$ 21,868	$ 25,554	$ 44,994	$ 45,678
Other comprehensive income (loss), before tax:
Change in net unrealized gains/losses during period	8,006	10,043	17,365	18,671
Reclassification adjustment for net (gains) losses included in income	(5)	(108)	(7)	(87)
Change in unamortized loss on available-for-sale securities transferred into held-to-maturity	464	452	929	904
Unrealized loss on derivatives	(486)	(804)	(437)	(3,002)
Defined benefit post-retirement benefits plans:
Change in net actuarial loss	(176)	13	(914)	28
Other comprehensive income (loss), before tax	7,803	9,596	16,936	16,514
Deferred tax benefit (expense) related to other comprehensive income	(3,214)	(3,775)	(6,812)	(6,498)
Other comprehensive income (loss), net of tax	4,589	5,821	10,124	10,016
Comprehensive income, net of tax	$ 26,457	$ 31,375	$ 55,118	$ 55,694

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, 2015	$ 950,493	$ 311,720	$ 638,367	$ 406
Comprehensive income:
Net income	45,678	0	45,678	0
Other comprehensive income, net of tax	10,016	0	0	10,016
Common stock transactions:
Common shares purchased and retired 998,135 and 789,743 in 2016 and 2015, respectively	(26,042)	(26,042)	0	0
Stock Issued During Period, 16,085 and 21,414 in 2016 and 2015, respectively	0	0	0	0
Non-vested common shares issued 189,624 and 169,577 in 2016 and 2015 respectively	0	0	0	0
25,984 and 3,484 non-vested common shares forfeited in 2016 and 2015 respectively	0	0	0	0
270,183 and 158,828 stock options exercised, net of 94,902 and 58,996 shares tendered in payment of option price and income tax withholding amounts in 2016 and 2015 respectively	1,684	1,684	0	0
Tax benefit of stock-based compensation	619	619	0	0
Stock-based compensation expense	2,385	2,385	0	0
Cash dividends declared:
Common ($0.66 per share) in 2016 and ($0.60 per share) in 2015	(19,708)	0	(19,708)	0
Ending Balance at Jun. 30, 2016	965,125	290,366	664,337	10,422
Beginning Balance at Dec. 31, 2016	982,593	296,071	694,650	(8,128)
Comprehensive income:
Net income	44,994	0	44,994	0
Other comprehensive income, net of tax	10,124	0	0	10,124
Common stock transactions:
Common shares purchased and retired 998,135 and 789,743 in 2016 and 2015, respectively	(891)	(891)	0	0
Stock Issued During Period, 16,085 and 21,414 in 2016 and 2015, respectively	385,969	385,969	0	0
Non-vested common shares issued 189,624 and 169,577 in 2016 and 2015 respectively	0	0	0	0
25,984 and 3,484 non-vested common shares forfeited in 2016 and 2015 respectively	0	0	0	0
270,183 and 158,828 stock options exercised, net of 94,902 and 58,996 shares tendered in payment of option price and income tax withholding amounts in 2016 and 2015 respectively	1,672	1,672	0	0
Stock-based compensation expense	2,468	2,468	0	0
Cash dividends declared:
Common ($0.66 per share) in 2016 and ($0.60 per share) in 2015	(21,551)	0	(21,551)	0
Ending Balance at Jun. 30, 2017	$ 1,405,378	$ 685,289	$ 718,093	$ 1,996

Consolidated Statements of Cha7

Consolidated Statements of Changes in Stockholders Equity (Unaudited) (Parenthetical) - $ / shares	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Common stock
Common stock transactions:
Common shares purchased and retired	21,454	995,600
Common shares issued	11,267,676	16,085
Non-vested common shares issued	134,044	189,624
Non-vested common shares forfeited	16,712	21,397
Stock options exercised	155,537	186,430
Shares tendered in payment of option price and income tax withholding amounts	50,698	57,153
Retained earnings
Cash dividends declared:
Common (in dollars per share)	$ 0.48	$ 0.44

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash flows from operating activities:
Net income	$ 44,994	$ 45,678
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	4,085	6,550
Net (gain) loss on disposal of property and equipment	76	188
Depreciation and amortization	9,665	9,491
Net premium amortization on investment securities	5,710	6,347
Net gains on investment securities transactions	(7)	(87)
Net gains on sales of mortgage loans held for sale	(9,898)	(10,544)
Net gain on sale of OREO	(217)	(636)
Write-downs of OREO and other assets pending disposal	60	621
Net Gain on Health Savings Accounts	(3,431)	0
Net reversal of impairment of mortgage servicing rights	(72)	(5)
Deferred income tax expense	(15,828)	321
Net increase in cash surrender value of company-owned life insurance policies	(2,587)	(2,271)
Stock-based compensation expense	2,468	2,385
Tax benefits from stock-based compensation expense	0	619
Excess tax benefits from stock-based compensation	0	(495)
Originations of loans held for sale	(428,286)	(468,560)
Proceeds from sales of loans held for sale	478,239	457,132
Changes in operating assets and liabilities:
Increase in interest receivable	(5,978)	281
Increase in other assets	26,231	(14,551)
Decrease in accrued interest payable	3,496	687
Decrease in accounts payable and accrued expenses	(20,170)	3,701
Net cash provided by operating activities	88,550	36,852
Cash flows from investing activities:
Purchases of held-to-maturity investment securities	(2,948)	(9,883)
Purchases of available-for-sale investment securities	(201,806)	(459,569)
Proceeds from maturities and paydowns of held-to-maturity investment securities	43,545	53,977
Proceeds from maturities and paydowns of available-for-sale investment securities	170,237	424,458
Purchases of company-owned life insurance	0	0
Extensions of credit to customers, net of repayments	(38,468)	(159,410)
Recoveries of loans charged-off	3,566	4,717
Proceeds from sales of OREO	1,712	2,398
Acquisition of intangible assets	28,013	0
Proceeds from the sale of Health Savings Accounts	6,500	0
Proceeds from sale of loan production office	0	932
Acquisition of bank and bank holding company, net of cash and cash equivalents received	91,775	0
Capital expenditures, net of sales	(7,548)	(3,638)
Net cash used in investing activities	38,552	(146,018)
Cash flows from financing activities:
Net increase (decrease) in deposits	(25,086)	(107,489)
Net increase (decrease) in repurchase agreements	42,216	(44,236)
Net increase (decrease) in other borrowed funds	15,013	13
Repayments of long-term debt	(34)	(32)
Advances on long-term debt	81	75
Proceeds from issuance of common stock	902	1,684
Excess tax benefits from stock-based compensation	0	495
Purchase and retirement of common stock	(891)	(26,042)
Dividends paid to common stockholders	(21,551)	(19,708)
Net cash provided by (used in) financing activities	10,650	(195,240)
Net increase (decrease) in cash and cash equivalents	137,752	(304,406)
Cash and cash equivalents at beginning of period	782,023	780,457
Cash and cash equivalents at end of period	919,775	476,051
Supplemental disclosures of cash flow information:
Cash paid during the period for income taxes	14,379	27,566
Cash paid during the period for interest expense	8,614	8,069
Transfer of loans to loans held for sale	5,805	26
Transfer of loans to other real estate owned	1,554	4,019
Capitalization of internally originated mortgage servicing rights	2,727	1,768
Investment securities available for sale	424,302	0
oncash or Part Noncash Acquisition, HTM Investments Acquired	57,307	0
Noncash or Part Noncash Acquisition, Loans Held for Sale Acquired	10,253	0
Noncash or Part Noncash Acquisition, Loans Acquired	2,080,083	0
Noncash or Part Noncash Acquisition, Fixed Assets Acquired	47,869	0
Noncash or Part Noncash Acquisition, Goodwill	231,507
Noncash or Part Noncash Acquisition, Value of Assets Acquired	3,025,728	0
Noncash or Part Noncash Acquisition, Intangible Assets Acquired	47,950	0
Noncash or Part Noncash Acquisition, Mortgage Servicing Asset Acquired	3,491	0
Noncash or Part Noncash Acquisition, Other Real Estate Owned Acquired	1,268	0
Noncash or Part Noncash Acquisition, Other Assets Acquired	121,698	0
Noncash or Part Noncash Acquisition, Deposits Acquired	2,668,976	0
Noncash or Part Noncash Acquisition, Payables Assumed	62,558	0
Noncash or Part Noncash Acquisition, Value of Liabilities Assumed	$ 2,731,534	$ 0

Basis of Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 2017
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 June 30, 2017 and December 31, 2016 , the results of operations for each of the three and six month periods ended June 30, 2017 and 2016 , and cash flows and changes in stockholders' equity for each of the six month periods ended June 30, 2017 and 2016 , in conformity with U.S. generally accepted accounting principles. The balance sheet information at December 31, 2016 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 June 30, 2017 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, 2016 . Operating results for the three and six months ended June 30, 2017 are not necessarily indicative of the results that may be expected for the year ending December 31, 2017 .

Acquisitions

Acquisitions	6 Months Ended
	Jun. 30, 2017
Business Combinations [Abstract]
Acquisitions	Acquisitions Cascade Bancorp. On November 17, 2016 , the Company entered into an agreement and plan of merger (the “Agreement”) to acquire all of the outstanding stock of Cascade Bancorp (“Cascade”), parent company of Bank of the Cascades, an Oregon-based community bank with 46 banking offices across Oregon, Idaho, and Washington. This transaction solidifies the Company's ability to strategically expand its community banking footprint in the Northwest corridor of the United States. The merger was completed on May 30, 2017 . Holders of each share of Cascade common stock received 0.14864 shares of First Interstate Class A common stock and $ 1.91 in cash, without interest, for each share of Cascade common stock. In connection with the merger, the Company issued approximately 11.3 million shares of First Interstate Class A common stock, which was valued at $ 34.30 per share, which was the closing price of First Interstate Class A common stock on the acquisition date. Cash paid by First Interstate was approximately $ 155.0 million, which included the cash portion of the merger consideration and the cash in lieu of fractional shares that Cascade Bancorp shareholders would have otherwise been entitled to receive. Total consideration exchanged in connection with the merger amounted to $ 541.0 million. All “in-the-money” Cascade options and all Cascade restricted stock units outstanding immediately prior to the transaction close were canceled in exchange for the right to receive a cash payment as provided in the merger agreement. The Company paid approximately $ 9.3 million in cash related to Cascade options and restricted stock units, which is included in consideration. Unvested Cascade restricted stock awards outstanding immediately prior to the transaction close were canceled in exchange for the right to receive a cash payment and Company shares as provided in the merger agreement. The Company paid a total of approximately $ 2.2 million in cash and issued approximately 168 thousand Company shares, valued at $ 34.30 per share, related to Cascade restricted stock awards. Of the cash paid and shares issued related to Cascade restricted stock awards, approximately $ 2.4 million was allocated to expense and excluded from consideration due to the acceleration of award vesting at the Company’s discretion. The remaining balance of approximately $ 5.5 million related to Cascade restricted stock awards is included in consideration. The assets and liabilities of Cascade were recorded in the Company's consolidated financial statements on a provisional basis at their estimated fair values as of the acquisition date and will be finalized in the coming months. The excess value of the consideration paid over the fair value of assets acquired and liabilities assumed is recorded as provisional goodwill. The preliminary purchase price allocation resulted in goodwill of $ 231.5 million, which is not deductible for income tax purposes. Goodwill resulting from the acquisition was allocated to the Company's one operating segment, community banking, and consists largely of the synergies and economies of scale expected from combining the operations of Cascade and the Company. The following table summarizes the consideration paid, fair values of the Cascade assets acquired and liabilities assumed, and the resulting goodwill. Due to the recent close of the transaction, all amounts reported are provisional pending the review of valuations obtained from third parties. As Recorded Fair Value As Recorded As of May 30, 2017 by Cascade Adjustments by the Company Assets acquired: Cash and cash equivalents $ 246,804 $ — $ 246,804 Investment securities 476,733 4,876 (1) 481,609 Loans held for investment 2,111,786 (31,703 ) (2) 2,080,083 Mortgage loans held for sale 10,253 — 10,253 Allowance for loan loss (23,974 ) 23,974 (3) — Premises and equipment 46,554 1,315 (4) 47,869 Other real estate owned ("OREO") 1,268 — 1,268 Core deposit intangible — 47,950 (5) 47,950 Deferred tax assets 32,232 (22,336 ) (6) 9,896 Other assets 113,915 1,378 (7) 115,293 Total assets acquired 3,015,571 25,454 3,041,025 Liabilities assumed: Deposits 2,669,910 (934 ) (8) 2,668,976 Accounts Payable and Accrued Expense 62,150 408 (9) 62,558 Total liabilities assumed 2,732,060 (526 ) 2,731,534 Net assets acquired $ 283,511 $ 24,928 309,491 Consideration paid: Cash 155,029 Class A common stock 385,969 Total consideration paid 540,998 Goodwill $ 231,507 Explanation of fair value adjustments: (1) Write up of the book value of investments to their estimated fair values on the date of acquisition based upon quotes obtained from an independent third party pricing service. (2) Write down of the book value of loans to their estimated fair values. Shared National Credits (SNC) were recorded at quoted sales prices where available. The fair value of the remaining loans was estimated using cash flow projections based on the remaining maturity and repricing terms, adjusted for estimated future credit losses and prepayments and discounted to present value using a risk-adjusted market rate for similar loans. The fair value of collateral dependent loans acquired with deteriorated credit quality was estimated based on the Company's analysis of the fair value of each loan's underlying collateral, discounted using market-derived rates of return with consideration given to the period of time and costs associated with foreclosure and disposition of the collateral. (3) Adjustment to remove the Cascade allowance for loan losses at acquisition date, as the credit risk is accounted for in the fair value adjustment for loans receivable described in (2) above. (4) Write up of the book value of premises and equipment to their estimated fair values on the date of acquisition based upon appraisals obtained from an independent third party appraiser or broker's opinion of value. (5) Adjustment represents the value of the core deposit base assumed in the acquisition based upon valuation from an independent accounting and advisory firm. (6) Adjustment consists of the write-off of pre-existing deferred tax assets as a result of the acquisition. (7) Adjustment consists of mortgage servicing rights assets as a result of the acquisition. (8) Decrease in book value of time deposits to their estimated fair values based upon interest rates of similar time deposits with similar terms on the date of acquisition based upon valuation from an independent accounting and advisory firm. (9) Increase in fair value due to credit card incentive program and swap liability offset. The core deposit intangible asset of $ 47,950 is being amortized using an accelerated method over the estimated useful lives of the related deposits of ten years. In accordance with Accounting Standards Codification ("ASC") Topic 805-740 "Business Combinations - Income Taxes," the Company reviewed its valuation allowance for deferred tax assets as a result of the Cascade acquisition. As part of evaluating whether or not the acquired deferred tax assets were realizable, the Company wrote-off state and local net operating losses to the balance that the Company determined would be realizable in future periods. The valuation allowance from Bank of the Cascades at the date of the acquisition related entirely to state and local net operating losses. As such, the Company reduced its valuation allowance for deferred tax assets to $ 0 . The Company recorded $ 10,133 and $ 10,838 in pre-tax merger related expenses for the three and six months ended June 30, 2017, respectively, including professional and legal fees of $ 5,926 and $ 6,542 , respectively, to directly consummate the merger. The remainder of expenses primarily relate to retention and severance compensation costs and service contract termination costs. These costs are incorporated in non-interest expenses in the Company’s consolidated statements of operations. The Company acquired certain loans that are subject to Accounting Standards Codification ("ASC") Topic 310-30 "Loans and Debt Securities Acquired with Deteriorated Credit Quality." ASC Topic 310-30 provides recognition, measurement and disclosure guidance for acquired loans that have evidence of deterioration in credit quality since origination for which it is probable, at acquisition, the Company will be unable to collect all contractual amounts owed. For loans that meet the criteria stipulated in ASC Topic 310-30, the excess of all cash flows expected at acquisition over the initial fair value of the loans acquired ("accretable yield") is amortized to interest income over the expected remaining lives of the underlying loans using the effective interest method. The accretable yield will fluctuate due to changes in (i) estimated lives of underling credit-impaired loans, (ii) assumptions regarding future principal and interest amounts collected, and (iii) indices used to fair value variable rate loans. Information regarding acquired credit-impaired loans as of the May 30, 2017 acquisition date is as follows: Contractually required principal and interest payments $ 48,041 Contractual cash flows not expected to be collected ("non-accretable discount") 23,376 Cash flows expected to be collected 24,665 Interest component of cash flows expected to be collected ("accretable discount") 1,901 Fair value of acquired credit-impaired loans $ 22,764 Information regarding acquired loans not deemed credit-impaired at the acquisition date is as follows: Contractually required principal and interest payments $ 2,098,155 Contractual cash flows not expected to be collected due to projected prepayment 23,387 Fair value at acquisition 2,067,572 The accompanying consolidated statements of income include the results of operations of the acquired entity from the May 30, 2017 acquisition date. For the period from May 30, 2017 to June 30, 2017, Cascade reported revenues of $ 12.9 million and net income of $ 3.0 million. The acquired entity will continue to operate as Bank of the Cascades until August 11, 2017 at which point the operations will be integrated with the Company's operations and Bank of the Cascades will merge with First Interstate Bank. The following table presents unaudited supplemental pro forma consolidated revenues and net income as if the acquisition had occurred as of January 1, 2016. Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 Interest income $ 103,248 $ 94,698 $ 203,326 $ 189,772 Non-interest income 41,314 44,780 77,897 78,286 Total revenues $ 144,562 $ 139,478 $ 281,223 $ 268,058 Net income $ 29,409 $ 29,534 $ 58,709 $ 23,716 EPS - basic $ 0.50 $ 0.53 $ 1.02 $ 0.43 EPS - diluted 0.50 0.53 1.01 0.42 The unaudited supplemental pro forma net income presented in the table above for 2017 was adjusted to exclude acquisition-related costs, including change in control expenses related to employee benefit plans and legal and professional expenses of $ 11,195 , net of tax. Pro forma net income presented in the table above for 2016 was adjusted to include the aforementioned acquisition-related costs. The unaudited supplemental pro forma net income presented in the table above for 2017 and 2016 includes adjustments for scheduled amortization of core deposit intangible assets acquired in the acquisition. The unaudited supplemental pro forma net income presented in the table above for 2017 and 2016 does not capture operating costs savings and other business synergies expected as a result of the acquisition.

Goodwill and intangibles (Notes

Goodwill and intangibles (Notes)	6 Months Ended
	Jun. 30, 2017
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill and Intangible Assets Disclosure [Text Block]	(3) Goodwill and Intangibles The Company recorded $ 231.5 million of provisional goodwill in connection with the Cascade merger. In accordance with the Intangibles - Goodwill and Other topic of the Financial Accounting Standards Board (“FASB”) ASC 350, goodwill is not amortized but is reviewed for potential impairment at the reporting unit level. Management analyzes its goodwill for impairment on an annual basis and between annual tests in certain circumstances, such as upon material adverse changes in legal, business, regulatory and economic factors. An impairment loss is recorded to the extent that the carrying amount of goodwill exceeds its implied fair value. The Company performed an impairment assessment as of July 1, 2016 and 2015 and concluded that there was no impairment to goodwill. Core deposit intangibles (“CDI”) are evaluated for impairment if events and circumstances indicate a possible impairment. The CDI are amortized using an accelerated method based on the estimated weighted average useful lives of the related deposits, which is ten years. The following table sets forth activity for CDI for the three and six months ended June 30, 2017 and 2016: Three months ended Six months ended June 30, June 30, 2017 2016 2017 2016 CDI, net, beginning of period 9,018 9,762 9,648 10,589 Established through acquisitions 47,950 — 47,950 — Reductions due to sale of accounts (3,069 ) — (3,069 ) — CDI current period amortization (1,062 ) (827 ) (1,692 ) (1,654 ) Total CDI, net, at June 30 52,837 8,935 52,837 8,935 Subsequent to the acquisition of Cascade, the Company sold the custodial rights to the all of its Health Savings Account (HSA) portfolio, including HSA acquired from Cascade. The Company recognized no gain or loss on the sale of the acquired HSA as the excess of consideration received over HSA book value was recorded as reduction to CDI at the acquisition of Cascade. The following table provides the estimated future CDI amortization expense: Years Ending December 31, 2017 remaining 2,597 2018 5,093 2019 4,994 2020 4,872 2021 4,729 Thereafter 22,164

Investment Securities

Investment Securities	6 Months Ended
	Jun. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Investment Securities	he amortized cost and approximate fair values of investment securities are summarized as follows: June 30, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Available-for-Sale: U.S. Treasury notes $ 3,607 $ 2 $ (2 ) $ 3,607 Obligations of U.S. government agencies 676,485 1,647 (2,814 ) 675,318 U.S. agency residential mortgage-backed securities & collateralized mortgage obligations 1,217,701 10,001 (4,765 ) 1,222,937 Private mortgage-backed securities 108,577 212 (304 ) 108,485 Corporate securities 66,793 97 (6 ) 66,884 Other investments 2,951 12 — 2,963 Total $ 2,076,114 $ 11,971 $ (7,891 ) $ 2,080,194 June 30, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Held-to-Maturity: State, county and municipal securities $ 188,486 $ 4,172 $ (141 ) $ 192,517 U.S agency residential mortgage-backed securities & 268,218 10,714 (9,360 ) 269,572 Obligations of U.S. government agencies 19,737 28 (5 ) 19,760 Corporate securities 52,804 333 (39 ) 53,098 Other investments 197 1 — 198 Total $ 529,442 $ 15,248 $ (9,545 ) $ 535,145 December 31, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Available-for-Sale: U.S. Treasury notes $ 3,608 $ 5 $ (1 ) $ 3,612 Obligations of U.S. government agencies 397,411 343 (6,457 ) 391,297 U.S. agency residential mortgage-backed securities & collateralized mortgage obligations 1,220,890 6,412 (13,601 ) 1,213,701 Private mortgage-backed securities 116 1 (1 ) 116 Other investments 2,951 21 — 2,972 Total $ 1,624,976 $ 6,782 $ (20,060 ) $ 1,611,698 December 31, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Held-to-Maturity: State, county and municipal securities $ 160,192 $ 2,723 $ (542 ) $ 162,373 Obligations of U.S. government agencies 19,737 — (162 ) 19,575 U.S. agency residential mortgage-backed securities & collateralized mortgage obligations 279,578 7,804 (9,249 ) 278,133 Corporate securities 53,032 139 (211 ) 52,960 Other investments 231 1 — 232 Total $ 512,770 $ 10,667 $ (10,164 ) $ 513,273 Gross realized gains and losses from the disposition of investment securities are summarized in the following table: Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Gross realized gains $ 5 $ 108 $ 7 $ 165 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 June 30, 2017 and December 31, 2016 : Less than 12 Months 12 Months or More Total June 30, 2017 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Available-for-Sale: U.S. Treasury notes $ 1,797 $ (2 ) $ — $ — $ 1,797 $ (2 ) Obligations of U.S. government agencies 359,889 (2,804 ) 9,989 (10 ) 369,878 (2,814 ) U.S. agency residential mortgage-backed securities & collateralized mortgage obligations 599,643 (4,346 ) 21,848 (419 ) 621,491 (4,765 ) Private mortgage-backed securities 1,484 (303 ) 42 (1 ) 1,526 (304 ) Corporate securities 8,100 (6 ) — — 8,100 (6 ) Total $ 970,913 $ (7,461 ) $ 31,879 $ (430 ) $ 1,002,792 $ (7,891 ) Less than 12 Months 12 Months or More Total June 30, 2017 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Held-to-Maturity: State, county and municipal securities $ 21,331 $ (139 ) $ 884 $ (2 ) $ 22,215 $ (141 ) U.S. agency residential mortgage-backed securities & collateralized mortgage obligations 42,109 (8,069 ) 17,766 (1,291 ) 59,875 (9,360 ) Obligations of U.S. government agencies 9,985 (5 ) — — 9,985 (5 ) Corporate securities 15,074 (39 ) — — 15,074 (39 ) Total $ 88,499 $ (8,252 ) $ 18,650 $ (1,293 ) $ 107,149 $ (9,545 ) Less than 12 Months 12 Months or More Total December 31, 2016 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Available-for-Sale: U.S. Treasury notes $ 598 $ (1 ) $ — $ — $ 598 $ (1 ) Obligations of U.S. government agencies 316,511 (6,457 ) — — 316,511 (6,457 ) U.S. agency residential mortgage-backed securities & collateralized mortgage obligations 746,265 (13,102 ) 15,801 (499 ) 762,066 (13,601 ) Private mortgage-backed securities — — 48 (1 ) 48 (1 ) Total $ 1,063,374 $ (19,560 ) $ 15,849 $ (500 ) $ 1,079,223 $ (20,060 ) Less than 12 Months 12 Months or More Total December 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 $ 42,518 $ (533 ) $ 2,831 $ (9 ) $ 45,349 $ (542 ) Obligations of U.S. government agencies 19,575 (162 ) — — 19,575 (162 ) U.S. agency residential mortgage-backed securities & collateralized mortgage obligations 108,857 (7,973 ) 19,986 (1,276 ) 128,843 (9,249 ) Corporate securities 32,474 (211 ) — — 32,474 (211 ) Total $ 203,424 $ (8,879 ) $ 22,817 $ (1,285 ) $ 226,241 $ (10,164 ) The investment portfolio is evaluated quarterly for other-than-temporary declines in the market value of each individual investment security. The Company had 337 and 396 individual investment securities that were in an unrealized loss position as of June 30, 2017 and December 31, 2016 , respectively. As of June 30, 2017 , 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 or six months ended June 30, 2017 or 2016 . Maturities of investment securities at June 30, 2017 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 June 30, 2017 Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair Value Within one year $ 371,218 $ 372,541 $ 75,748 $ 74,416 After one year but within five years 1,227,734 1,229,254 268,855 280,504 After five years but within ten years 228,192 228,561 133,245 134,858 After ten years 248,970 249,838 51,594 45,367 Total $ 2,076,114 $ 2,080,194 $ 529,442 $ 535,145 As of June 30, 2017 , the Company had investment securities callable within one year with amortized costs and estimated fair values of $ 63,743 and $ 63,933 , respectively. These investment securities are primarily included in the after one year but within five years category in the table above. As of June 30, 2017 , the Company did not have any callable structured notes.

Loans

Loans	6 Months Ended
	Jun. 30, 2017
Receivables [Abstract]
Loans	Loans The following tables present the Company's recorded investment and contractual aging of the Company's recorded investment in loans by class as of the dates indicated. Loans are considered past due if the required principal and interest payments have not been received as of the date such payments were due. Total Loans 30 - 59 60 - 89 > 90 30 or More Days Days Days Days Current Non-accrual Total As of June 30, 2017 Past Due Past Due Past Due Past Due Loans Loans Loans Real estate Commercial $ 4,522 $ 419 $ 978 $ 5,919 $ 2,780,010 $ 30,597 $ 2,816,526 Construction: Land acquisition & development 1,880 42 52 1,974 333,247 4,663 339,884 Residential 1,124 508 — 1,632 217,914 210 219,756 Commercial — — — — 117,287 4,318 121,605 Total construction loans 3,004 550 52 3,606 668,448 9,191 681,245 Residential 14,136 2,583 3,583 20,302 1,441,507 4,205 1,466,014 Agricultural 1,371 661 1,900 3,932 156,898 2,345 163,175 Total real estate loans 23,033 4,213 6,513 33,759 5,046,863 46,338 5,126,960 Consumer: Indirect consumer 6,430 1,648 159 8,237 769,361 1,428 779,026 Other consumer 1,246 301 87 1,634 173,713 390 175,737 Credit card 488 355 487 1,330 74,300 1 75,631 Total consumer loans 8,164 2,304 733 11,201 1,017,374 1,819 1,030,394 Commercial 3,487 1,248 1,684 6,419 1,178,688 25,762 1,210,869 Agricultural 1,618 487 432 2,537 143,824 2,768 149,129 Other, including overdrafts — — — — 8,238 — 8,238 Loans held for investment 36,302 8,252 9,362 53,916 7,394,987 76,687 7,525,590 Mortgage loans originated for sale — — — — 30,383 — 30,383 Total loans $ 36,302 $ 8,252 $ 9,362 $ 53,916 $ 7,425,370 $ 76,687 $ 7,555,973 Total Loans 30 - 59 60 - 89 > 90 30 or More Days Days Days Days Current Non-accrual Total As of December 31, 2016 Past Due Past Due Past Due Past Due Loans Loans Loans Real estate Commercial $ 7,307 $ 1,099 $ 303 $ 8,709 $ 1,799,525 $ 26,211 $ 1,834,445 Construction: Land acquisition & development 633 352 279 1,264 202,223 5,025 208,512 Residential 931 264 — 1,195 146,245 456 147,896 Commercial — — — — 124,827 762 125,589 Total construction loans 1,564 616 279 2,459 473,295 6,243 481,997 Residential 3,986 1,280 702 5,968 1,014,990 6,435 1,027,393 Agricultural 341 287 — 628 165,293 4,327 170,248 Total real estate loans 13,198 3,282 1,284 17,764 3,453,103 43,216 3,514,083 Consumer: Indirect consumer 8,425 2,329 712 11,466 740,163 780 752,409 Other consumer 1,322 235 167 1,724 146,006 357 148,087 Credit card 504 333 567 1,404 68,366 — 69,770 Total consumer loans 10,251 2,897 1,446 14,594 954,535 1,137 970,266 Commercial 3,171 727 734 4,632 767,878 25,432 797,942 Agricultural 1,518 362 14 1,894 127,956 3,008 132,858 Other, including overdrafts — 1 311 312 1,289 — 1,601 Loans held for investment 28,138 7,269 3,789 39,196 5,304,761 72,793 5,416,750 Mortgage loans originated for sale — — — — 61,794 — 61,794 Total loans $ 28,138 $ 7,269 $ 3,789 $ 39,196 $ 5,366,555 $ 72,793 $ 5,478,544 Loans from business combinations included in the tables 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 balances and accrual status of loans acquired with credit impairment as of June 30, 2017 and 2016 : As of June 30, 2017 2016 Outstanding balance $ 60,195 $ 31,979 Carrying value Loans on accrual status 39,359 20,140 Total carrying value $ 39,359 $ 20,140 The following table summarizes changes in the accretable yield for loans acquired credit impaired for the three and six months ended June 30, 2017 and 2016 : Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Beginning balance $ 6,432 $ 6,678 $ 6,803 $ 6,713 Additions 1,929 — 1,929 — Accretion income (668 ) (615 ) (1,273 ) (1,229 ) Reductions due to exit events (418 ) (158 ) (988 ) (305 ) Reclassifications from nonaccretable differences 375 — 1,179 726 Ending balance $ 7,650 $ 5,905 $ 7,650 $ 5,905 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 $ 919 and $ 821 for the three months ended June 30, 2017 and 2016 , respectively, and approximately $1,772 and $1,690 for the six months ended June 30, 2017, and 2016, respectively. The Company considers impaired loans to include all originated loans, except consumer loans, that are risk rated as doubtful, or have been placed on non-accrual status or renegotiated in troubled debt restructurings, and all loans acquired with evidence of deterioration in credit quality and for which it was probable, at acquisition, that the Company would be unable to collect all contractual amounts owed. The following tables present information on the Company’s recorded investment in impaired loans as of dates indicated: As of June 30, 2017 Unpaid Total Principal Balance Recorded Investment With No Allowance Recorded Investment With Allowance Total Recorded Investment Related Allowance Real estate: Commercial $ 53,576 $ 22,751 $ 20,380 $ 43,131 $ 5,158 Construction: Land acquisition & development 11,281 3,639 1,718 5,357 741 Residential 312 209 — 209 — Commercial 4,728 226 4,204 4,430 2,828 Total construction loans 16,321 4,074 5,922 9,996 3,569 Residential 7,636 4,472 2,022 6,494 170 Agricultural 2,752 2,549 153 2,702 9 Total real estate loans 80,285 33,846 28,477 62,323 8,906 Consumer 28 — 25 25 — Commercial 39,587 13,021 18,882 31,903 6,882 Agricultural 3,001 2,040 940 2,980 528 Total $ 122,901 $ 48,907 $ 48,324 $ 97,231 $ 16,316 As of December 31, 2016 Unpaid Total Principal Balance Recorded Investment With No Allowance Recorded Investment With Allowance Total Recorded Investment Related Allowance Real estate: Commercial $ 57,017 $ 24,410 $ 21,420 $ 45,830 $ 2,847 Construction: Land acquisition & development 12,084 4,330 1,813 6,143 826 Residential 1,555 219 619 838 1 Commercial 4,786 3,940 647 4,587 657 Total construction loans 18,425 8,489 3,079 11,568 1,484 Residential 8,222 4,074 2,470 6,544 253 Agricultural 5,069 4,509 181 4,690 4 Total real estate loans 88,733 41,482 27,150 68,632 4,588 Commercial 40,314 13,230 19,167 32,397 9,254 Agricultural 3,738 3,280 382 3,662 112 Total $ 132,785 $ 57,992 $ 46,699 $ 104,691 $ 13,954 The following table presents the average recorded investment in and income recognized on impaired loans for the periods indicated: Three Months Ended June 30, 2017 2016 Average Recorded Investment Income Recognized Average Recorded Investment Income Recognized Real estate: Commercial $ 43,871 $ 102 $ 34,576 $ 105 Construction: Land acquisition & development 5,411 4 7,096 12 Residential 212 — 277 — Commercial 4,463 1 1,421 2 Total construction loans 10,086 5 8,794 14 Residential 6,574 4 3,067 2 Agricultural 2,389 — 5,857 — Total real estate loans 62,920 111 52,294 121 Consumer 13 — — — Commercial 32,491 60 28,074 41 Agricultural 2,068 — 753 — Total $ 97,492 $ 171 $ 81,121 $ 162 Six Months Ended June 30, 2017 2016 Average Recorded Investment Income Recognized Average Recorded Investment Income Recognized Real estate: Commercial $ 44,481 $ 227 $ 36,342 $ 141 Construction: Land acquisition & development 5,750 8 7,277 19 Residential 524 — 282 — Commercial 4,509 44 1,433 2 Total construction loans 10,783 52 8,992 21 Residential 6,519 8 4,138 3 Agricultural 3,696 — 5,671 1 Total real estate loans 65,479 287 55,143 166 Consumer 13 — — — Commercial 32,150 109 28,133 56 Agricultural 3,321 2 846 — Total $ 100,963 $ 398 $ 84,122 $ 222 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 $ 919 and $ 964 for the three months ended June 30, 2017 and 2016 , respectively, and approximately $1,772 and $2,020 for the six months ended June 30, 2017 and 2016, respectively. 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 changes, 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 may be 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, although they continue to be individually evaluated for impairment and disclosed as impaired loans. The Company had loans renegotiated in troubled debt restructurings of $ 52,351 as of June 30, 2017 , of which $ 37,395 were included in non-accrual loans and $ 14,956 were on accrual status. The Company had loans renegotiated in troubled debt restructurings of $ 49,652 as of December 31, 2016 , of which $ 27,309 were included in non-accrual loans and $ 22,343 were on accrual status. The following table presents information on the Company's troubled debt restructurings that occurred during the three and six months ended June 30, 2017 : Number of Notes Type of Concession Principal Balance at Restructure Date Three Months Ended June 30, 2017 Interest only period Extension of term or amortization schedule Interest rate adjustment Other (1) Commercial real estate 1 $ — $ 226 $ — $ — $ 226 Commercial 2 16 — — 465 481 Total loans restructured during period 3 $ 16 $ 226 $ — $ 465 $ 707 (1) Other includes concessions that reduce or defer payments for a specified period of time and/or concessions that do not fit into other designated categories. Number of Notes Type of Concession Principal Balance at Restructure Date Six Months Ended June 30, 2017 Interest only period Extension of terms or maturity Interest rate adjustment Other (1) Commercial real estate 5 $ 1,475 $ 388 $ — $ 909 $ 2,772 Commercial 15 511 1,968 — 5,446 7,925 Total loans restructured during period 20 $ 1,986 $ 2,356 $ — $ 6,355 $ 10,697 (1) Other includes concessions that reduce or defer payments for a specified period of time and/or do not fit into other designated categories. 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 or six months ended June 30, 2017 or 2016 . 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 and six months ended June 30, 2017 . 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 June 30, 2017 Six Months Ended June 30, 2017 Number of Notes Balance Number of Notes Balance Commercial real estate 3 $ 2,763 3 $ 2,763 Commercial construction 1 3,575 1 3,575 Total 4 $ 6,338 4 $ 6,338 At June 30, 2017 , 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 June 30, 2017 Other Assets Especially Mentioned Substandard Doubtful Total Criticized Loans Real estate: Commercial $ 89,093 $ 105,050 $ 14,265 $ 208,408 Construction: Land acquisition & development 17,516 6,785 1,383 25,684 Residential 2,609 2,503 548 5,660 Commercial 1,520 3,844 4,221 9,585 Total construction loans 21,645 13,132 6,152 40,929 Residential 4,831 11,754 874 17,459 Agricultural 1,319 16,016 — 17,335 Total real estate loans 116,888 145,952 21,291 284,131 Consumer: Indirect consumer 707 2,096 126 2,929 Other consumer 609 835 135 1,579 Credit card — 185 — 185 Total consumer loans 1,316 3,116 261 4,693 Commercial 39,346 57,731 21,310 118,387 Agricultural 5,526 15,612 1,327 22,465 Total $ 163,076 $ 222,411 $ 44,189 $ 429,676 As of December 31, 2016 Other Assets Especially Mentioned Substandard Doubtful Total Criticized Loans Real estate: Commercial $ 85,292 $ 85,293 $ 10,842 $ 181,427 Construction: Land acquisition & development 13,414 6,214 1,401 21,029 Residential 412 1,621 656 2,689 Commercial 1,555 6,344 664 8,563 Total construction loans 15,381 14,179 2,721 32,281 Residential 5,038 12,472 764 18,274 Agricultural 3,831 17,813 — 21,644 Total real estate loans 109,542 129,757 14,327 253,626 Consumer: Indirect consumer 778 1,527 101 2,406 Other consumer 681 1,036 264 1,981 Total consumer loans 1,459 2,563 365 4,387 Commercial 46,402 29,281 21,240 96,923 Agricultural 6,178 10,724 404 17,306 Total $ 163,581 $ 172,325 $ 36,336 $ 372,242 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	6 Months Ended
	Jun. 30, 2017
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 June 30, 2017 Real Estate Consumer Commercial Agriculture Other Total Allowance for loan losses: Beginning balance $ 33,092 $ 8,368 $ 33,562 $ 1,209 $ — $ 76,231 Provision charged to operating expense 1,078 489 453 335 — 2,355 Less loans charged-off (980 ) (2,412 ) (1,049 ) (48 ) — (4,489 ) Add back recoveries of loans previously charged-off 308 1,109 158 29 — 1,604 Ending balance $ 33,498 $ 7,554 $ 33,124 $ 1,525 $ — $ 75,701 Six Months Ended June 30, 2017 Real Estate Consumer Commercial Agriculture Other Total Allowance for loan losses: Beginning balance $ 28,625 $ 7,711 $ 38,092 $ 1,786 $ — $ 76,214 Provision charged to operating expense 5,465 2,537 (3,675 ) (242 ) — 4,085 Less loans charged-off (1,243 ) (5,008 ) (1,841 ) (70 ) — (8,162 ) Add back recoveries of loans previously charged-off 651 2,314 548 51 — 3,564 Ending balance $ 33,498 $ 7,554 $ 33,124 $ 1,525 $ — $ 75,701 As of June 30, 2017 Real Estate Consumer Commercial Agriculture Other Total Allowance for loan losses: Loans individually evaluated for impairment $ 8,898 $ 8 $ 6,882 $ 528 $ — $ 16,316 Loans collectively evaluated for impairment 24,600 7,546 26,242 997 — 59,385 Allowance for loan losses $ 33,498 $ 7,554 $ 33,124 $ 1,525 $ — $ 75,701 Loans held for investment: Individually evaluated for impairment $ 62,323 $ 25 $ 31,903 $ 2,980 $ — $ 97,231 Collectively evaluated for impairment 5,064,637 1,030,369 1,178,966 146,149 8,238 7,428,359 Total loans $ 5,126,960 $ 1,030,394 $ 1,210,869 $ 149,129 $ 8,238 $ 7,525,590 Three Months Ended June 30, 2016 Real Estate Consumer Commercial Agriculture Other Total Allowance for loan losses: Beginning balance $ 36,652 $ 5,256 $ 36,252 $ 1,764 $ — $ 79,924 Provision charged to operating expense (4,059 ) 2,123 4,313 173 — 2,550 Less loans charged-off (523 ) (1,712 ) (1,018 ) (188 ) — (3,441 ) Add back recoveries of loans previously charged-off 211 648 448 — — 1,307 Ending balance $ 32,281 $ 6,315 $ 39,995 $ 1,749 $ — $ 80,340 Six Months Ended June 30, 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 (20,140 ) 3,352 22,003 1,335 — 6,550 Less loans charged-off (2,445 ) (3,604 ) (1,506 ) (188 ) — (7,743 ) Add back recoveries of loans previously charged-off 2,570 1,423 723 — — 4,716 Ending balance $ 32,281 $ 6,315 $ 39,995 $ 1,749 $ — $ 80,340 As of December 31, 2016 Real Estate Consumer Commercial Agriculture Other Total Allowance for loan losses: Loans individually evaluated for impairment $ 4,588 $ — $ 9,254 $ 112 $ — $ 13,954 Loans collectively evaluated for impairment 24,037 7,711 28,838 1,674 — 62,260 Allowance for loan losses $ 28,625 $ 7,711 $ 38,092 $ 1,786 $ — $ 76,214 Loans held for investment: Individually evaluated for impairment $ 68,632 $ — $ 32,397 $ 3,662 $ — $ 104,691 Collectively evaluated for impairment 3,445,451 970,266 765,545 129,196 1,601 5,312,059 Total loans $ 3,514,083 $ 970,266 $ 797,942 $ 132,858 $ 1,601 $ 5,416,750 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 June 30, 2017 and December 31, 2016 , the Company's allowance for loan losses included $701 and $427 , respectively, related to loans acquired credit impaired.

OREO

OREO	6 Months Ended
	Jun. 30, 2017
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 June 30, Six Months Ended June 30, 2017 2016 2017 2016 Beginning balance $ 9,428 $ 9,257 $ 10,019 $ 6,254 OREO acquired through acquisition 1,055 — 1,055 — Additions 1,395 792 1,763 4,019 Valuation adjustments (9 ) (586 ) (56 ) (603 ) Dispositions (583 ) (1,555 ) (1,495 ) (1,762 ) Ending balance $ 11,286 $ 7,908 $ 11,286 $ 7,908 The carrying values of foreclosed residential real estate properties included in other real estate owned were $ 2,686 and $2,282 as of June 30, 2017 and December 31, 2016, 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 June 30, 2017 or December 31, 2016.

Derivatives and Hedging

Derivatives and Hedging	6 Months Ended
	Jun. 30, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities Disclosure [Text Block]	Derivatives and Hedging Activities For asset and liability management purposes, the Company has entered into an interest rate swap contract to hedge against changes in forecasted cash flows due to interest rate exposures. The swap agreement is a derivative instrument and converts 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. The Company also 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. 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 from 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 forward loan sales contracts. 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 contracts act as a hedge against the variability in the market value of mortgage loans held for 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. June 30, 2017 December 31, 2016 Notional Amount Estimated Fair Value Notional Amount Estimated Fair Value Derivative Assets (included in other assets): Non-hedging interest rate derivatives: Interest rate swap contracts $ 320,809 $ 9,001 $ 53,593 $ 1,332 Interest rate lock commitments 64,673 1,301 73,422 1,131 Forward loan sales contracts 82,589 297 126,836 286 Total derivative assets $ 468,071 $ 10,599 $ 253,851 $ 2,749 Derivative Liabilities (included in accounts payable and accrued expenses): Derivatives designated as hedges: Interest rate swap contracts $ 100,000 $ 470 $ 100,000 $ 33 Non-hedging interest rate derivatives: Interest rate swap contracts 320,809 9,327 53,593 1,281 Total derivative liabilities $ 420,809 $ 9,797 $ 153,593 $ 1,314 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 effective portion of changes in the fair value of derivatives designated and that qualify as cash flow hedges is recorded in Accumulated Other Comprehensive Income and is subsequently reclassified into earnings in the period that the hedged forecasted transaction affects earnings. The ineffective portion of the change in fair value of the derivatives is recognized directly in earnings. During the three and six months ended June 30, 2017, the Company did not record any hedge ineffectiveness. Derivative assets and liabilities are recorded at fair value on the balance sheet and do not take into account the effects of master netting arrangements. Master netting arrangements allow the Company to settle all contracts held with a single counterparty on a net basis and to offset net contract position with related collateral where applicable. The following table illustrates the potential effect of the Company's master netting arrangements, by type of financial instrument, on the Company's consolidated balance sheets as of June 30, 2017 and December 31, 2016: June 30, 2017 Gross Amounts Recognized Gross Amounts Offset in the Balance Sheet Net Amounts in the Balance Sheet Financial Instruments Fair Value of Financial Collateral in the Balance Sheet Net Amount Financial Assets Interest rate swap contracts $ 9,001 $ — $ 9,001 $ 1,547 $ — $ 7,454 Mortgage related derivatives 1,598 — 1,598 — — 1,598 Total derivatives 10,599 — 10,599 1,547 — 9,052 Total assets $ 10,599 $ — $ 10,599 $ 1,547 $ — $ 9,052 Financial Liabilities Interest rate swap contracts $ 9,797 $ — $ 9,797 $ 1,547 $ 8,250 $ — Total derivatives 9,797 — 9,797 1,547 8,250 — Repurchase agreements 579,772 — 579,772 — 579,772 — Total liabilities $ 589,569 $ — $ 589,569 $ 1,547 $ 588,022 $ — December 31, 2016 Gross Amounts Recognized Gross Amounts Offset in the Balance Sheet Net Amounts in the Balance Sheet Financial Instruments Fair Value of Financial Collateral in the Balance Sheet Net Amount Financial Assets Interest rate swap contracts $ 1,332 $ — $ 1,332 $ 479 $ — $ 853 Mortgage related derivatives 1,417 — 1,417 — — 1,417 Total derivatives 2,749 — 2,749 479 — 2,270 Total assets $ 2,749 $ — $ 2,749 $ 479 $ — $ 2,270 Financial Liabilities Interest rate swap contracts $ 1,314 $ — $ 1,314 $ 479 $ — $ 835 Total derivatives 1,314 — 1,314 479 — 835 Repurchase agreements 537,556 — 537,556 — 537,556 — Total liabilities $ 538,870 $ — $ 538,870 $ 479 $ 537,556 $ 835 Amounts reported in accumulated other comprehensive income related to derivatives will be reclassified to interest expense as interest payments are made on the Company’s variable-rate borrowings. During the next twelve months, the Company estimates that $ 372 will be reclassified as an increase to interest expense. 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 June 30, Six Months Ended June 30, 2017 2016 2017 2016 Derivatives designated as hedges: Amount of loss recognized in other comprehensive income (effective portion) $ (486 ) $ (804 ) $ (437 ) $ (3,002 ) Non-hedging interest rate derivatives: Amount of gain (loss) recognized in other non-interest income 70 (50 ) 31 (79 ) Amount of net fee expense recognized in other non-interest income 321 245 279 245 Amount of net gains recognized in mortgage banking revenues 290 523 181 1,218

Capital Stock

Capital Stock	6 Months Ended
	Jun. 30, 2017
Equity [Abstract]
Common Stock	Capital Stock The Company had 33,260,710 shares of Class A common stock and 23,184,557 shares of Class B common stock outstanding as of June 30, 2017 . The Company had 21,613,885 shares of Class A common stock and 23,312,291 shares of Class B common stock outstanding as of December 31, 2016 . On May 30, 2017, the Company issued 11,252,750 shares of its Class A common stock with an aggregate value of $ 385,969 as partial consideration for the acquisition of Cascade Bancorp. In addition, during the six months ended June 30, 2017, the Company issued 14,926 shares of its Class A common stock to directors for their annual service on the Company's board of directors. The aggregate value of the shares issued to directors of $ 522 is included in stock-based compensation expense in the accompanying consolidated statements of changes in stockholders' equity. During the six months ended June 30, 2017 , the Company did not repurchase any shares of its Class A common stock. During the six months ended June 30, 2016 , the Company repurchased and retired 975,877 shares of its Class A common stock in open market transactions at an aggregate purchase price of $25,525 . All 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 24,123 shares of its Class A common stock. All other stock repurchases during the six months ended June 30, 2017 and 2016 were redemptions of vested restricted shares tendered in lieu of cash for payment of income tax withholding amounts by participants in the Company's equity compensation plans.

Earnings per Common Share

Earnings per Common Share	6 Months Ended
	Jun. 30, 2017
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 six month periods ended June 30, 2017 and 2016 : Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Net income $ 21,868 $ 25,554 $ 44,994 $ 45,678 Weighted average common shares outstanding for basic earnings per share computation 47,612,971 44,268,985 46,170,500 44,494,102 Dilutive effects of stock-based compensation 461,480 376,190 510,875 385,513 Weighted average common shares outstanding for diluted earnings per common share computation 48,074,451 44,645,175 46,681,375 44,879,615 Basic earnings per common share $ 0.46 $ 0.58 $ 0.97 $ 1.03 Diluted earnings per common share $ 0.45 $ 0.57 $ 0.96 $ 1.02 Anti-dilutive unvested time restricted stock 96,262 96,726 92,626 96,726 The Company had 182,835 and 221,322 shares of unvested restricted stock as of June 30, 2017 and 2016 , respectively, that were not included in the computation of diluted earnings per common share because performance conditions for vesting had not been met.

Regulatory Capital

Regulatory Capital	6 Months Ended
	Jun. 30, 2017
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 June 30, 2017 and December 31, 2016 , 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 June 30, 2017 and December 31, 2016 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 June 30, 2017 Total risk-based capital: Consolidated $ 1,086,842 12.56 % $ 800,182 9.25 % $ 908,314 10.50 % $ 865,061 10.00 % FIB 824,454 13.00 586,642 9.25 665,918 10.50 634,208 10.00 BOTC 240,391 10.53 211,145 9.25 239,678 10.50 228,265 10.00 Tier 1 risk-based capital: Consolidated 1,011,141 11.69 627,169 7.25 735,302 8.50 692,049 8.00 FIB 748,753 11.81 459,801 7.25 539,077 8.50 507,366 8.00 BOTC 240,391 10.53 165,492 7.25 194,025 8.50 182,612 8.00 Common equity tier 1 risk-based capital: Consolidated 931,675 10.77 497,410 5.75 605,543 7.00 562,290 6.50 FIB 748,753 11.81 364,669 5.75 443,945 7.00 412,235 6.50 BOTC 240,391 10.53 131,252 5.75 159,786 7.00 148,372 6.50 Leverage capital ratio: Consolidated 1,011,141 10.65 379,616 4.00 379,616 4.00 474,519 5.00 FIB 748,753 8.67 345,442 4.00 345,442 4.00 431,803 5.00 BOTC 240,391 8.12 118,476 4.00 118,476 4.00 148,095 5.00 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, 2016 Total risk-based capital: Consolidated $ 974,488 15.13 % $ 555,665 8.63 % $ 676,070 10.50 % $ 643,876 10.00 % FIB 841,967 13.13 553,459 8.63 673,386 10.50 641,320 10.00 Tier 1 risk-based capital: Consolidated 894,273 13.89 426,890 6.63 547,295 8.50 $ 515,101 8.00 FIB 765,753 11.94 425,195 6.63 545,122 8.50 513,056 8.00 Common equity tier 1 risk-based capital: Consolidated 814,273 12.65 330,308 5.13 450,713 7.00 $ 418,519 6.50 FIB 765,753 11.94 328,997 5.13 448,924 7.00 416,858 6.50 Leverage capital ratio: Consolidated 894,273 10.11 353,838 4.00 353,838 4.00 $ 442,297 5.00 FIB 765,753 8.69 352,283 4.00 352,283 4.00 440,353 5.00 (1) The ratios for the well capitalized requirement are only applicable to FIB and BOTC. 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	6 Months Ended
	Jun. 30, 2017
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 June 30, 2017 , 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 8 — Derivatives and Hedging Activity. As of June 30, 2017 , the Company had commitments under construction contracts of $1,374 . 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 $ 999 of sold residential mortgage loans with recourse provisions still in effect as of June 30, 2017 .

Financial Instruments with Off-

Financial Instruments with Off-Balance Sheet Risk	6 Months Ended
	Jun. 30, 2017
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 June 30, 2017 , commitments to extend credit to existing and new borrowers approximated $ 2,250,387 , which included $ 673,280 on unused credit card lines and $ 874,134 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 June 30, 2017 , the Company had outstanding standby letters of credit of $ 54,241 . 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	6 Months Ended
	Jun. 30, 2017
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 June 30, 2017 2016 2017 2016 2017 2016 Investment securities available-for sale: Change in net unrealized gains during period $ 8,006 $ 10,043 $ 3,298 $ 3,947 $ 4,708 $ 6,096 Reclassification adjustment for net (gains) losses included in net income (5 ) (108 ) (2 ) (42 ) (3 ) (66 ) Change in unamortized loss on available- for-sale securities transferred into held-to- maturity 464 452 191 170 273 282 Unrealized (gain) loss on derivatives (486 ) (804 ) (201 ) (305 ) (285 ) (499 ) Defined benefits post-retirement benefit plan: Change in net actuarial (gain) loss (176 ) 13 (72 ) 5 (104 ) 8 Total other comprehensive income $ 7,803 $ 9,596 $ 3,214 $ 3,775 $ 4,589 $ 5,821 Pre-tax Tax Expense (Benefit) Net of Tax Six Months Ended June 30, 2017 2016 2017 2016 2017 2016 Investment securities available-for sale: Change in net unrealized gains during period $ 17,365 $ 18,671 $ 6,985 $ 7,322 $ 10,380 $ 11,349 Reclassification adjustment for net gains included in net income (7 ) (87 ) (3 ) (34 ) (4 ) (53 ) Change in unamortized loss on available- for-sale securities transferred into held-to- maturity 929 904 374 340 555 564 Unrealized loss on derivatives (437 ) (3,002 ) (176 ) (1,141 ) (261 ) (1,861 ) Defined benefits post-retirement benefit plan: Change in net actuarial loss (914 ) 28 (368 ) 11 (546 ) 17 Total other comprehensive income $ 16,936 $ 16,514 $ 6,812 $ 6,498 $ 10,124 $ 10,016 The components of accumulated other comprehensive loss, net of related tax effects, are as follows: June 30, December 31, Net unrealized gain (loss) on investment securities available-for-sale $ 947 $ (10,143 ) Net realized gain (loss) on derivatives (434 ) (23 ) Net actuarial gain (loss) on defined benefit post-retirement benefit plans 1,483 2,038 Net accumulated other comprehensive gain (loss) $ 1,996 $ (8,128 )

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2017
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 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 are classified within Level 2 of the valuation hierarchy. There were no transfers between fair value hierarchy levels during the three and six months ended June 30, 2017 and 2016 . 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 as well as loan level pricing adjustments. 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 federal 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. Observable data is then adjusted to reflect changes in interest rates, the Company's estimated pull-through rate and estimated direct costs necessary to complete the commitment into a closed loan net of origination and processing fees collected from the borrower. 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. 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 June 30, 2017 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 $ 3,607 $ — $ 3,607 $ — Obligations of U.S. government agencies 675,318 — 675,318 — U.S. agencies mortgage-backed securities & collateralized mortgage obligations 1,222,937 — 1,222,937 — Private mortgage-backed securities 108,485 — 108,485 — Corporate securities 66,884 — 66,884 Other investments 2,963 — 2,963 — Loans held for sale 30,383 — 30,383 — Derivative assets: Interest rate swap contracts 9,001 — 9,001 — Interest rate lock commitments 1,301 — 1,301 — Forward loan sale contracts 297 — 297 — Derivative liabilities: Interest rate swap contracts 9,797 — 9,797 — Deferred compensation plan assets 11,598 — 11,598 — Deferred compensation plan liabilities 11,598 — 11,598 — Fair Value Measurements at Reporting Date Using As of December 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 $ 3,612 $ — $ 3,612 $ — Obligations of U.S. government agencies 391,297 — 391,297 — U.S. agencies mortgage-backed securities & collateralized mortgage obligations 1,213,701 — 1,213,701 — Private mortgage-backed securities 116 — 116 — Other investments 2,972 — 2,972 — Loans held for sale 61,794 — 61,794 — Derivative assets: Interest rate swap contracts 1,332 — 1,332 — Interest rate lock commitments 1,131 — 1,131 — Forward loan sales contracts 286 — 286 — Derivative liabilities Interest rate swap contracts 1,314 — 1,314 — Deferred compensation plan assets 10,627 — 10,627 — Deferred compensation plan liabilities 10,627 — 10,627 — 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 June 30, 2017 Balance Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Impaired loans $ 34,975 $ — $ — $ 34,975 Other real estate owned 1,422 — — 1,422 Long-lived assets to be disposed of by sale 356 — — 356 Fair Value Measurements at Reporting Date Using As of December 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 $ 39,344 $ — $ — $ 39,344 Other real estate owned 2,110 — — 2,110 Long-lived assets to be disposed of by sale 1,335 — — 1,335 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 June 30, 2017 , certain impaired loans with a carrying value of $ 61,122 were reduced by specific valuation allowance allocations of $ 15,614 and partial loan charge-offs of $ 10,533 resulting in a reported fair value of $ 34,975 . As of December 31, 2016 , certain impaired loans with a carrying value of $ 65,238 were reduced by specific valuation allowance allocations of $ 13,954 and partial loan charge-offs of $ 11,941 resulting in a reported fair value of $ 39,344 . 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 $56 during the six months ended June 30, 2017 included $25 directly related to receipt of updated appraisals and $ 31 based on management estimates of the current fair value of properties. Write downs of $603 during the six months ended June 30, 2016 included $550 directly related to receipt of updated appraisals and $ 53 based on management estimates of the current fair value of 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 June 30, 2017 , the Company had a long-lived asset to be disposed of by sale with a carrying value of $565 that was reduced by write-downs of $209 , resulting in a fair value of $356 . As of December 31, 2016 , 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 $1,028 resulting in an aggregate fair value of $1,335 . 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 June 30, 2017 December 31, 2016 Valuation Technique Unobservable Inputs Range (Weighted Average) Impaired loans $ 34,975 $ 39,344 Appraisal Appraisal adjustment 0% - 66% (31%) Other real estate owned 1,422 2,110 Appraisal Appraisal adjustment 8% - 96% (18%) Long-lived assets to be disposed of by sale 356 1,335 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 June 30, 2017 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 $ 919,775 $ 919,775 $ 919,775 $ — $ — Investment securities available-for-sale 2,080,194 2,080,194 — 2,080,194 — Investment securities held-to-maturity 529,442 535,145 — 535,145 — Accrued interest receivable 35,830 35,830 — 35,830 — Mortgage servicing rights, net 23,715 34,580 — 34,580 — Loans held for sale 30,383 30,383 — 30,383 — Net loans held for investment 7,449,889 7,325,012 — 7,290,037 34,975 Derivative assets 10,599 10,599 — 10,599 — Deferred compensation plan assets 11,598 11,598 — 11,598 — Total financial assets $ 11,091,425 $ 10,983,116 $ 919,775 $ 10,028,366 $ 34,975 Financial liabilities: Total deposits, excluding time deposits $ 8,817,211 $ 8,817,211 $ 8,817,211 $ — $ — Time deposits 1,202,789 1,195,454 — 1,195,454 — Securities sold under repurchase agreements 579,772 579,772 — 579,772 — Other borrowed funds 15,019 15,019 — 15,019 — Accrued interest payable 8,917 8,917 — 8,917 — Long-term debt 28,017 28,240 — 28,240 — Subordinated debentures held by subsidiary trusts 82,477 91,519 — 91,519 — Derivative liabilities 9,797 9,797 — 9,797 — Deferred compensation plan liabilities 11,598 11,598 — 11,598 — Total financial liabilities $ 10,755,597 $ 10,757,527 $ 8,817,211 $ 1,940,316 $ — Fair Value Measurements at Reporting Date Using As of December 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 $ 782,023 $ 782,023 $ 782,023 $ — $ — Investment securities available-for-sale 1,611,698 1,611,698 — 1,611,698 — Investment securities held-to-maturity 512,770 513,273 — 513,273 — Accrued interest receivable 29,852 29,852 — 29,852 — Mortgage servicing rights, net 18,457 35,656 — 35,656 — Loans held for sale 61,794 61,794 — 61,794 Net loans held for investment 5,340,536 5,248,127 — 5,208,783 39,344 Derivative assets 2,749 2,749 — 2,749 — Deferred compensation plan assets 10,627 10,627 — 10,627 — Total financial assets $ 8,370,506 $ 8,295,799 $ 782,023 $ 7,474,432 $ 39,344 Financial liabilities: Total deposits, excluding time deposits $ 6,324,512 $ 6,324,512 $ 6,324,512 $ — $ — Time deposits 1,051,598 1,044,670 — 1,044,670 — Securities sold under repurchase agreements 537,556 537,556 — 537,556 — Other borrowed funds 6 6 — 6 — Accrued interest payable 5,421 5,421 — 5,421 — Long-term debt 27,970 27,477 — 27,477 — Subordinated debentures held by subsidiary trusts 82,477 73,554 — 73,554 — Derivative liabilities 1,314 1,314 — 1,314 — Deferred compensation plan liabilities 10,627 10,627 — 10,627 — Total financial liabilities $ 8,041,481 $ 8,025,137 $ 6,324,512 $ 1,700,625 $ —

Recent Authoritative Accounting

Recent Authoritative Accounting Guidance	6 Months Ended
	Jun. 30, 2017
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." In May 2014, the FASB issued ASU 2014-09, "Revenue from Contracts with Customers (Topic 606)." ASU 2014-09 introduced 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 ASU 2014-09 for all entities by one year until January 1, 2018. In March 2016, the FASB issued ASU 2016-08, "Revenue from Contracts with Customers (Topic 606): Principal vs 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. In April 2016, the FASB issued ASU 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. While the assessment of the aforementioned provisions of ASU 2014-09 is not complete, the timing of the Company's revenue recognition is not expected to materially change. The Company will continue to evaluate any impact as additional guidance is issued and our internal assessment progresses. ASU 2016-01 "Financial Instruments-Overall: Recognition and Measurement of Financial Assets and Financial Liabilities." In January 2016, the FASB issued ASU 2016-10, "Financial Instruments - Overall (Subtopic 825-10): 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)." In February 2016, the FASB issued ASU 2016-02, "Leases (Topic 842)." 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 redesignation of that hedging relationship provided that all other hedge accounting criteria continue to be met. The amendments in ASU 2016-05 became effective for the Company on January 1, 2017, and did not impact 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 that 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 became effective for the Company on January 1, 2017, and did not impact the Company’s 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 excludes the amount of excess tax benefits that would have previously been recognized in additional paid-in capital. Additionally, excess tax benefits are 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 Company has elected to 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 became effective for the Company on January 1, 2017, and resulted in a $2,154 reduction in income tax expense during the six months ended June 30, 2017, of which $1,703 was due to the the recognition of excess tax benefits related to outstanding stock option awards exercised during the period and $451 was due to the recognition of excess tax benefits related to the vesting of restricted stock. ASU No. 2016-13 "Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments." The amendments in ASU 2016-13 require a financial asset or group of financial assets measured at amortized cost basis to be presented on a company's financial statements at the net amount expected to be collected based on historical experience, current conditions and reasonable and supportable forecasts. ASU 2016-13 requires a company's income statement to reflect the measurement of credit losses for newly recognized financial assets as well as the expected increases or decreases of expected credit losses that have taken place during the period. The amendments in ASU 2016-13 require that the allowance for credit losses for purchased financial assets with a more-than-insignificant amount of credit deterioration since origination be measured at amortized cost basis with the initial allowance for credit losses added to the purchase price rather than being reported as a credit loss expense. ASU 2016-13 also requires that credit losses relating to available-for-sale debt securities be recorded through an allowance for credit losses. The amendments in ASU 2016-13 are effective for the Company for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. The amendments will be applied through a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period. A prospective transition approach is required for debt securities for which other-than-temporary impairment was recognized before the effective date. Amounts previously recognized in accumulated other comprehensive income as of the date of adoption that relate to improvement in cash flows expected to be collected will continue to be accreted into income over the remaining life of the asset. Recoveries of amounts previously written off relating to improvements in cash flows after the date of adoption will be recorded in earnings when received. The Company is currently evaluating the new guidance to determine the impact it will have on its consolidated financial statements, results of operations and liquidity. ASU No. 2016-15 "Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments." The amendments in ASU 2016-15 are intended to reduce diversity in practice in how eight particular transactions are classified in the statement of cash flows. The amendments in ASU 2016-15 are effective for the Company on January 1, 2018. Early adoption is permitted, provided that all of the amendments are adopted in the same period. Entities will be required to apply the guidance retrospectively. If it is impracticable to apply the guidance retrospectively for an issue, the amendments related to that issue would be applied prospectively. The amendments in ASU 2016-15 only affect the classification of certain items within the statement of cash flows, and are not expected to have a significant impact on the Company’s consolidated financial statements, results of operations or liquidity. ASU No. 2017-01 "Business Combinations (Topic 805): Clarifying the Definition of a Business.” ASU 2017-01 clarifies the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The amendments in this update provide a screen to determine when a set is not a business. The screen requires that when substantially all of the fair value of the gross assets acquired (or disposed of) is concentrated in a single identifiable asset or a group of similar identifiable assets, the set is not a business. This screen reduces the number of transactions that need to be further evaluated. If the screen is not met, the amendments in this update (1) require that to be considered a business, a set must include, at a minimum, an input and a substantive process that together significantly contribute to the ability to create output and (2) remove the evaluation of whether a market participant could replace missing elements. The amendments provide a framework to assist entities in evaluating whether both an input and a substantive process are present. The framework includes two sets of criteria to consider that depend on whether a set has outputs. ASU 2017-01 is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. As we approach the effective date, we will consult the framework to determine the impact on the Company's consolidated financial statements, results of operations or liquidity. ASU No. 2017-04, “Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment.” The amendments in ASU 2017-04 remove Step 2 of the goodwill impairment test, which requires a hypothetical purchase price allocation. Goodwill impairment will now be the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. All other goodwill impairment guidance will remain largely unchanged. ASU No. 2017-04 is effective for interim and annual reporting periods beginning after December 15, 2019, applied prospectively. Early adoption is permitted for any impairment tests performed after January 1, 2017. The amendments in ASU 2017-04 are not expected to have a significant impact on the Company’s consolidated financial statements, results of operations or liquidity. ASU No. 2017-07, “Compensation - Retirement Benefits (Topic 750): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost.” The amendments in ASU 2017-07 requires employers to present the service cost component of the net periodic benefit cost in the same income statement line item as other employee compensation costs arising from services rendered during the period. The other components of net benefit cost are required to be presented in the income separately from the service cost component and outside a subtotal of income from operations, if one is presented. The amendments in ASU 2017-07 also allow only the service cost component to be eligible for capitalization. ASU No. 2017-07 is effective for the Company for interim and annual reporting periods beginning after December 15, 2017, with early adoption permitted. The amendments in ASU 2017-07 are applied retrospectively for the presentation of the service cost and other components of net periodic benefit cost in the income statement and prospectively for the capitalization of the service cost in other assets. ASU 2017-07 allows the use of a practical expedient that permits an employer to use the amounts disclosed in its pension and other post-retirement benefits plan footnote for the prior comparative periods as the estimation basis for applying the retrospective presentation requirements. Adoption of the amendments in ASU 2017-07 will not have a significant impact on the Company’s consolidated financial statements, results of operations or liquidity. ASU No. 2017-08, “Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities.” The amendments in ASU 2017-08 shorten the amortization period for the premium on certain purchased callable debt securities to the earliest call date. The new guidance does not change the accounting for purchased callable debt securities held at a discount; the discount continues to be amortized to maturity. ASU No. 2017-08 is effective for interim and annual reporting periods beginning after December 15, 2018, with early adoption permitted. The guidance calls for a modified retrospective transition approach under which a cumulative-effect adjustment will be made to retained earnings as of the beginning of the first reporting period in which the guidance is adopted. The Company currently amortizes premiums on callable debt securities to the earliest call date. As such, the amendments in ASU 2017-08 will not impact the Company's consolidated financial statements, results of operations and liquidity. ASU 2017-09, "Compensation - Stock Compensation (Topic 718): Scope of Modification Accounting." In May 2017, the FASB issued ASU 2017-09, which clarifies when a change to the terms or conditions of a share-based payment award must be accounted for as a modification. Under the new guidance, an entity will not apply modification accounting to a share-based payment award if there is no change to the award's fair value, vesting conditions and classification as an equity or liability instrument. The guidance is effective prospectively for all companies for annual periods beginning after December 15, 2017. Early adoption is permitted. The Company is currently evaluating the impact the standard may have on its consolidated financial statements, results of operations and liquidity.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2017
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 SEC. On July 20, 2017 , the Company declared a quarterly dividend to common shareholders of $ 0.24 per share, to be paid on August 11, 2017 to shareholders of record as of August 2, 2017 . No other events requiring recognition or disclosure were identified.

Acquisitions (Tables)

Acquisitions (Tables)	6 Months Ended
	Jun. 30, 2017
Business Combinations [Abstract]
Schedule of acquired loans with credit impairment	Contractually required principal and interest payments $ 48,041 Contractual cash flows not expected to be collected ("non-accretable discount") 23,376 Cash flows expected to be collected 24,665 Interest component of cash flows expected to be collected ("accretable discount") 1,901 Fair value of acquired credit-impaired loans $ 22,764 The following table displays the outstanding unpaid balances and accrual status of loans acquired with credit impairment as of June 30, 2017 and 2016 : As of June 30, 2017 2016 Outstanding balance $ 60,195 $ 31,979 Carrying value Loans on accrual status 39,359 20,140 Total carrying value $ 39,359 $ 20,140 The following table summarizes changes in the accretable yield for loans acquired credit impaired for the three and six months ended June 30, 2017 and 2016 : Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Beginning balance $ 6,432 $ 6,678 $ 6,803 $ 6,713 Additions 1,929 — 1,929 — Accretion income (668 ) (615 ) (1,273 ) (1,229 ) Reductions due to exit events (418 ) (158 ) (988 ) (305 ) Reclassifications from nonaccretable differences 375 — 1,179 726 Ending balance $ 7,650 $ 5,905 $ 7,650 $ 5,905
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]	As Recorded Fair Value As Recorded As of May 30, 2017 by Cascade Adjustments by the Company Assets acquired: Cash and cash equivalents $ 246,804 $ — $ 246,804 Investment securities 476,733 4,876 (1) 481,609 Loans held for investment 2,111,786 (31,703 ) (2) 2,080,083 Mortgage loans held for sale 10,253 — 10,253 Allowance for loan loss (23,974 ) 23,974 (3) — Premises and equipment 46,554 1,315 (4) 47,869 Other real estate owned ("OREO") 1,268 — 1,268 Core deposit intangible — 47,950 (5) 47,950 Deferred tax assets 32,232 (22,336 ) (6) 9,896 Other assets 113,915 1,378 (7) 115,293 Total assets acquired 3,015,571 25,454 3,041,025 Liabilities assumed: Deposits 2,669,910 (934 ) (8) 2,668,976 Accounts Payable and Accrued Expense 62,150 408 (9) 62,558 Total liabilities assumed 2,732,060 (526 ) 2,731,534 Net assets acquired $ 283,511 $ 24,928 309,491 Consideration paid: Cash 155,029 Class A common stock 385,969 Total consideration paid 540,998 Goodwill $ 231,507
Schedule of Acquired Loans not Deemed to Have Credit Impairment [Table Text Block]	Contractually required principal and interest payments $ 2,098,155 Contractual cash flows not expected to be collected due to projected prepayment 23,387 Fair value at acquisition 2,067,572
Business Acquisition, Pro Forma Information [Table Text Block]	Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 Interest income $ 103,248 $ 94,698 $ 203,326 $ 189,772 Non-interest income 41,314 44,780 77,897 78,286 Total revenues $ 144,562 $ 139,478 $ 281,223 $ 268,058 Net income $ 29,409 $ 29,534 $ 58,709 $ 23,716 EPS - basic $ 0.50 $ 0.53 $ 1.02 $ 0.43 EPS - diluted 0.50 0.53 1.01 0.42

Goodwill and intangibles (Table

Goodwill and intangibles (Tables)	6 Months Ended
	Jun. 30, 2017
Goodwill and Intangibles [Abstract]
Schedule of Finite-Lived Intangible Assets [Table Text Block]	Three months ended Six months ended June 30, June 30, 2017 2016 2017 2016 CDI, net, beginning of period 9,018 9,762 9,648 10,589 Established through acquisitions 47,950 — 47,950 — Reductions due to sale of accounts (3,069 ) — (3,069 ) — CDI current period amortization (1,062 ) (827 ) (1,692 ) (1,654 ) Total CDI, net, at June 30 52,837 8,935 52,837 8,935
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]	Years Ending December 31, 2017 remaining 2,597 2018 5,093 2019 4,994 2020 4,872 2021 4,729 Thereafter 22,164

Investment Securities (Tables)

Investment Securities (Tables)	6 Months Ended
	Jun. 30, 2017
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: June 30, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Available-for-Sale: U.S. Treasury notes $ 3,607 $ 2 $ (2 ) $ 3,607 Obligations of U.S. government agencies 676,485 1,647 (2,814 ) 675,318 U.S. agency residential mortgage-backed securities & collateralized mortgage obligations 1,217,701 10,001 (4,765 ) 1,222,937 Private mortgage-backed securities 108,577 212 (304 ) 108,485 Corporate securities 66,793 97 (6 ) 66,884 Other investments 2,951 12 — 2,963 Total $ 2,076,114 $ 11,971 $ (7,891 ) $ 2,080,194 June 30, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Held-to-Maturity: State, county and municipal securities $ 188,486 $ 4,172 $ (141 ) $ 192,517 U.S agency residential mortgage-backed securities & 268,218 10,714 (9,360 ) 269,572 Obligations of U.S. government agencies 19,737 28 (5 ) 19,760 Corporate securities 52,804 333 (39 ) 53,098 Other investments 197 1 — 198 Total $ 529,442 $ 15,248 $ (9,545 ) $ 535,145 December 31, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Available-for-Sale: U.S. Treasury notes $ 3,608 $ 5 $ (1 ) $ 3,612 Obligations of U.S. government agencies 397,411 343 (6,457 ) 391,297 U.S. agency residential mortgage-backed securities & collateralized mortgage obligations 1,220,890 6,412 (13,601 ) 1,213,701 Private mortgage-backed securities 116 1 (1 ) 116 Other investments 2,951 21 — 2,972 Total $ 1,624,976 $ 6,782 $ (20,060 ) $ 1,611,698 December 31, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Held-to-Maturity: State, county and municipal securities $ 160,192 $ 2,723 $ (542 ) $ 162,373 Obligations of U.S. government agencies 19,737 — (162 ) 19,575 U.S. agency residential mortgage-backed securities & collateralized mortgage obligations 279,578 7,804 (9,249 ) 278,133 Corporate securities 53,032 139 (211 ) 52,960 Other investments 231 1 — 232 Total $ 512,770 $ 10,667 $ (10,164 ) $ 513,273
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 June 30, Six Months Ended June 30, 2017 2016 2017 2016 Gross realized gains $ 5 $ 108 $ 7 $ 165 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 June 30, 2017 and December 31, 2016 : Less than 12 Months 12 Months or More Total June 30, 2017 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Available-for-Sale: U.S. Treasury notes $ 1,797 $ (2 ) $ — $ — $ 1,797 $ (2 ) Obligations of U.S. government agencies 359,889 (2,804 ) 9,989 (10 ) 369,878 (2,814 ) U.S. agency residential mortgage-backed securities & collateralized mortgage obligations 599,643 (4,346 ) 21,848 (419 ) 621,491 (4,765 ) Private mortgage-backed securities 1,484 (303 ) 42 (1 ) 1,526 (304 ) Corporate securities 8,100 (6 ) — — 8,100 (6 ) Total $ 970,913 $ (7,461 ) $ 31,879 $ (430 ) $ 1,002,792 $ (7,891 ) Less than 12 Months 12 Months or More Total June 30, 2017 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Held-to-Maturity: State, county and municipal securities $ 21,331 $ (139 ) $ 884 $ (2 ) $ 22,215 $ (141 ) U.S. agency residential mortgage-backed securities & collateralized mortgage obligations 42,109 (8,069 ) 17,766 (1,291 ) 59,875 (9,360 ) Obligations of U.S. government agencies 9,985 (5 ) — — 9,985 (5 ) Corporate securities 15,074 (39 ) — — 15,074 (39 ) Total $ 88,499 $ (8,252 ) $ 18,650 $ (1,293 ) $ 107,149 $ (9,545 ) Less than 12 Months 12 Months or More Total December 31, 2016 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Available-for-Sale: U.S. Treasury notes $ 598 $ (1 ) $ — $ — $ 598 $ (1 ) Obligations of U.S. government agencies 316,511 (6,457 ) — — 316,511 (6,457 ) U.S. agency residential mortgage-backed securities & collateralized mortgage obligations 746,265 (13,102 ) 15,801 (499 ) 762,066 (13,601 ) Private mortgage-backed securities — — 48 (1 ) 48 (1 ) Total $ 1,063,374 $ (19,560 ) $ 15,849 $ (500 ) $ 1,079,223 $ (20,060 ) Less than 12 Months 12 Months or More Total December 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 $ 42,518 $ (533 ) $ 2,831 $ (9 ) $ 45,349 $ (542 ) Obligations of U.S. government agencies 19,575 (162 ) — — 19,575 (162 ) U.S. agency residential mortgage-backed securities & collateralized mortgage obligations 108,857 (7,973 ) 19,986 (1,276 ) 128,843 (9,249 ) Corporate securities 32,474 (211 ) — — 32,474 (211 ) Total $ 203,424 $ (8,879 ) $ 22,817 $ (1,285 ) $ 226,241 $ (10,164 )
Maturities of Investment Securities	Maturities of investment securities at June 30, 2017 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 June 30, 2017 Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair Value Within one year $ 371,218 $ 372,541 $ 75,748 $ 74,416 After one year but within five years 1,227,734 1,229,254 268,855 280,504 After five years but within ten years 228,192 228,561 133,245 134,858 After ten years 248,970 249,838 51,594 45,367 Total $ 2,076,114 $ 2,080,194 $ 529,442 $ 535,145

Loans (Tables)

Loans (Tables)	6 Months Ended
	Jun. 30, 2017
Receivables [Abstract]
Schedule of Recorded Investment in Past Due Loans by Class	Total Loans 30 - 59 60 - 89 > 90 30 or More Days Days Days Days Current Non-accrual Total As of June 30, 2017 Past Due Past Due Past Due Past Due Loans Loans Loans Real estate Commercial $ 4,522 $ 419 $ 978 $ 5,919 $ 2,780,010 $ 30,597 $ 2,816,526 Construction: Land acquisition & development 1,880 42 52 1,974 333,247 4,663 339,884 Residential 1,124 508 — 1,632 217,914 210 219,756 Commercial — — — — 117,287 4,318 121,605 Total construction loans 3,004 550 52 3,606 668,448 9,191 681,245 Residential 14,136 2,583 3,583 20,302 1,441,507 4,205 1,466,014 Agricultural 1,371 661 1,900 3,932 156,898 2,345 163,175 Total real estate loans 23,033 4,213 6,513 33,759 5,046,863 46,338 5,126,960 Consumer: Indirect consumer 6,430 1,648 159 8,237 769,361 1,428 779,026 Other consumer 1,246 301 87 1,634 173,713 390 175,737 Credit card 488 355 487 1,330 74,300 1 75,631 Total consumer loans 8,164 2,304 733 11,201 1,017,374 1,819 1,030,394 Commercial 3,487 1,248 1,684 6,419 1,178,688 25,762 1,210,869 Agricultural 1,618 487 432 2,537 143,824 2,768 149,129 Other, including overdrafts — — — — 8,238 — 8,238 Loans held for investment 36,302 8,252 9,362 53,916 7,394,987 76,687 7,525,590 Mortgage loans originated for sale — — — — 30,383 — 30,383 Total loans $ 36,302 $ 8,252 $ 9,362 $ 53,916 $ 7,425,370 $ 76,687 $ 7,555,973 Total Loans 30 - 59 60 - 89 > 90 30 or More Days Days Days Days Current Non-accrual Total As of December 31, 2016 Past Due Past Due Past Due Past Due Loans Loans Loans Real estate Commercial $ 7,307 $ 1,099 $ 303 $ 8,709 $ 1,799,525 $ 26,211 $ 1,834,445 Construction: Land acquisition & development 633 352 279 1,264 202,223 5,025 208,512 Residential 931 264 — 1,195 146,245 456 147,896 Commercial — — — — 124,827 762 125,589 Total construction loans 1,564 616 279 2,459 473,295 6,243 481,997 Residential 3,986 1,280 702 5,968 1,014,990 6,435 1,027,393 Agricultural 341 287 — 628 165,293 4,327 170,248 Total real estate loans 13,198 3,282 1,284 17,764 3,453,103 43,216 3,514,083 Consumer: Indirect consumer 8,425 2,329 712 11,466 740,163 780 752,409 Other consumer 1,322 235 167 1,724 146,006 357 148,087 Credit card 504 333 567 1,404 68,366 — 69,770 Total consumer loans 10,251 2,897 1,446 14,594 954,535 1,137 970,266 Commercial 3,171 727 734 4,632 767,878 25,432 797,942 Agricultural 1,518 362 14 1,894 127,956 3,008 132,858 Other, including overdrafts — 1 311 312 1,289 — 1,601 Loans held for investment 28,138 7,269 3,789 39,196 5,304,761 72,793 5,416,750 Mortgage loans originated for sale — — — — 61,794 — 61,794 Total loans $ 28,138 $ 7,269 $ 3,789 $ 39,196 $ 5,366,555 $ 72,793 $ 5,478,544
Schedule of acquired loans with credit impairment	Contractually required principal and interest payments $ 48,041 Contractual cash flows not expected to be collected ("non-accretable discount") 23,376 Cash flows expected to be collected 24,665 Interest component of cash flows expected to be collected ("accretable discount") 1,901 Fair value of acquired credit-impaired loans $ 22,764 The following table displays the outstanding unpaid balances and accrual status of loans acquired with credit impairment as of June 30, 2017 and 2016 : As of June 30, 2017 2016 Outstanding balance $ 60,195 $ 31,979 Carrying value Loans on accrual status 39,359 20,140 Total carrying value $ 39,359 $ 20,140 The following table summarizes changes in the accretable yield for loans acquired credit impaired for the three and six months ended June 30, 2017 and 2016 : Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Beginning balance $ 6,432 $ 6,678 $ 6,803 $ 6,713 Additions 1,929 — 1,929 — Accretion income (668 ) (615 ) (1,273 ) (1,229 ) Reductions due to exit events (418 ) (158 ) (988 ) (305 ) Reclassifications from nonaccretable differences 375 — 1,179 726 Ending balance $ 7,650 $ 5,905 $ 7,650 $ 5,905
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 June 30, 2017 Unpaid Total Principal Balance Recorded Investment With No Allowance Recorded Investment With Allowance Total Recorded Investment Related Allowance Real estate: Commercial $ 53,576 $ 22,751 $ 20,380 $ 43,131 $ 5,158 Construction: Land acquisition & development 11,281 3,639 1,718 5,357 741 Residential 312 209 — 209 — Commercial 4,728 226 4,204 4,430 2,828 Total construction loans 16,321 4,074 5,922 9,996 3,569 Residential 7,636 4,472 2,022 6,494 170 Agricultural 2,752 2,549 153 2,702 9 Total real estate loans 80,285 33,846 28,477 62,323 8,906 Consumer 28 — 25 25 — Commercial 39,587 13,021 18,882 31,903 6,882 Agricultural 3,001 2,040 940 2,980 528 Total $ 122,901 $ 48,907 $ 48,324 $ 97,231 $ 16,316 As of December 31, 2016 Unpaid Total Principal Balance Recorded Investment With No Allowance Recorded Investment With Allowance Total Recorded Investment Related Allowance Real estate: Commercial $ 57,017 $ 24,410 $ 21,420 $ 45,830 $ 2,847 Construction: Land acquisition & development 12,084 4,330 1,813 6,143 826 Residential 1,555 219 619 838 1 Commercial 4,786 3,940 647 4,587 657 Total construction loans 18,425 8,489 3,079 11,568 1,484 Residential 8,222 4,074 2,470 6,544 253 Agricultural 5,069 4,509 181 4,690 4 Total real estate loans 88,733 41,482 27,150 68,632 4,588 Commercial 40,314 13,230 19,167 32,397 9,254 Agricultural 3,738 3,280 382 3,662 112 Total $ 132,785 $ 57,992 $ 46,699 $ 104,691 $ 13,954 The following table presents the average recorded investment in and income recognized on impaired loans for the periods indicated: Three Months Ended June 30, 2017 2016 Average Recorded Investment Income Recognized Average Recorded Investment Income Recognized Real estate: Commercial $ 43,871 $ 102 $ 34,576 $ 105 Construction: Land acquisition & development 5,411 4 7,096 12 Residential 212 — 277 — Commercial 4,463 1 1,421 2 Total construction loans 10,086 5 8,794 14 Residential 6,574 4 3,067 2 Agricultural 2,389 — 5,857 — Total real estate loans 62,920 111 52,294 121 Consumer 13 — — — Commercial 32,491 60 28,074 41 Agricultural 2,068 — 753 — Total $ 97,492 $ 171 $ 81,121 $ 162 Six Months Ended June 30, 2017 2016 Average Recorded Investment Income Recognized Average Recorded Investment Income Recognized Real estate: Commercial $ 44,481 $ 227 $ 36,342 $ 141 Construction: Land acquisition & development 5,750 8 7,277 19 Residential 524 — 282 — Commercial 4,509 44 1,433 2 Total construction loans 10,783 52 8,992 21 Residential 6,519 8 4,138 3 Agricultural 3,696 — 5,671 1 Total real estate loans 65,479 287 55,143 166 Consumer 13 — — — Commercial 32,150 109 28,133 56 Agricultural 3,321 2 846 — Total $ 100,963 $ 398 $ 84,122 $ 222
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 June 30, 2017 Six Months Ended June 30, 2017 Number of Notes Balance Number of Notes Balance Commercial real estate 3 $ 2,763 3 $ 2,763 Commercial construction 1 3,575 1 3,575 Total 4 $ 6,338 4 $ 6,338 Number of Notes Type of Concession Principal Balance at Restructure Date Three Months Ended June 30, 2017 Interest only period Extension of term or amortization schedule Interest rate adjustment Other (1) Commercial real estate 1 $ — $ 226 $ — $ — $ 226 Commercial 2 16 — — 465 481 Total loans restructured during period 3 $ 16 $ 226 $ — $ 465 $ 707 (1) Other includes concessions that reduce or defer payments for a specified period of time and/or concessions that do not fit into other designated categories. Number of Notes Type of Concession Principal Balance at Restructure Date Six Months Ended June 30, 2017 Interest only period Extension of terms or maturity Interest rate adjustment Other (1) Commercial real estate 5 $ 1,475 $ 388 $ — $ 909 $ 2,772 Commercial 15 511 1,968 — 5,446 7,925 Total loans restructured during period 20 $ 1,986 $ 2,356 $ — $ 6,355 $ 10,697 (1) Other includes concessions that reduce or defer payments for a specified period of time and/or do not fit into other designated categories.
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 June 30, 2017 Other Assets Especially Mentioned Substandard Doubtful Total Criticized Loans Real estate: Commercial $ 89,093 $ 105,050 $ 14,265 $ 208,408 Construction: Land acquisition & development 17,516 6,785 1,383 25,684 Residential 2,609 2,503 548 5,660 Commercial 1,520 3,844 4,221 9,585 Total construction loans 21,645 13,132 6,152 40,929 Residential 4,831 11,754 874 17,459 Agricultural 1,319 16,016 — 17,335 Total real estate loans 116,888 145,952 21,291 284,131 Consumer: Indirect consumer 707 2,096 126 2,929 Other consumer 609 835 135 1,579 Credit card — 185 — 185 Total consumer loans 1,316 3,116 261 4,693 Commercial 39,346 57,731 21,310 118,387 Agricultural 5,526 15,612 1,327 22,465 Total $ 163,076 $ 222,411 $ 44,189 $ 429,676 As of December 31, 2016 Other Assets Especially Mentioned Substandard Doubtful Total Criticized Loans Real estate: Commercial $ 85,292 $ 85,293 $ 10,842 $ 181,427 Construction: Land acquisition & development 13,414 6,214 1,401 21,029 Residential 412 1,621 656 2,689 Commercial 1,555 6,344 664 8,563 Total construction loans 15,381 14,179 2,721 32,281 Residential 5,038 12,472 764 18,274 Agricultural 3,831 17,813 — 21,644 Total real estate loans 109,542 129,757 14,327 253,626 Consumer: Indirect consumer 778 1,527 101 2,406 Other consumer 681 1,036 264 1,981 Total consumer loans 1,459 2,563 365 4,387 Commercial 46,402 29,281 21,240 96,923 Agricultural 6,178 10,724 404 17,306 Total $ 163,581 $ 172,325 $ 36,336 $ 372,242

Allowance for Loan Losses (Tabl

Allowance for Loan Losses (Tables)	6 Months Ended
	Jun. 30, 2017
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 June 30, 2017 Real Estate Consumer Commercial Agriculture Other Total Allowance for loan losses: Beginning balance $ 33,092 $ 8,368 $ 33,562 $ 1,209 $ — $ 76,231 Provision charged to operating expense 1,078 489 453 335 — 2,355 Less loans charged-off (980 ) (2,412 ) (1,049 ) (48 ) — (4,489 ) Add back recoveries of loans previously charged-off 308 1,109 158 29 — 1,604 Ending balance $ 33,498 $ 7,554 $ 33,124 $ 1,525 $ — $ 75,701 Six Months Ended June 30, 2017 Real Estate Consumer Commercial Agriculture Other Total Allowance for loan losses: Beginning balance $ 28,625 $ 7,711 $ 38,092 $ 1,786 $ — $ 76,214 Provision charged to operating expense 5,465 2,537 (3,675 ) (242 ) — 4,085 Less loans charged-off (1,243 ) (5,008 ) (1,841 ) (70 ) — (8,162 ) Add back recoveries of loans previously charged-off 651 2,314 548 51 — 3,564 Ending balance $ 33,498 $ 7,554 $ 33,124 $ 1,525 $ — $ 75,701 As of June 30, 2017 Real Estate Consumer Commercial Agriculture Other Total Allowance for loan losses: Loans individually evaluated for impairment $ 8,898 $ 8 $ 6,882 $ 528 $ — $ 16,316 Loans collectively evaluated for impairment 24,600 7,546 26,242 997 — 59,385 Allowance for loan losses $ 33,498 $ 7,554 $ 33,124 $ 1,525 $ — $ 75,701 Loans held for investment: Individually evaluated for impairment $ 62,323 $ 25 $ 31,903 $ 2,980 $ — $ 97,231 Collectively evaluated for impairment 5,064,637 1,030,369 1,178,966 146,149 8,238 7,428,359 Total loans $ 5,126,960 $ 1,030,394 $ 1,210,869 $ 149,129 $ 8,238 $ 7,525,590 Three Months Ended June 30, 2016 Real Estate Consumer Commercial Agriculture Other Total Allowance for loan losses: Beginning balance $ 36,652 $ 5,256 $ 36,252 $ 1,764 $ — $ 79,924 Provision charged to operating expense (4,059 ) 2,123 4,313 173 — 2,550 Less loans charged-off (523 ) (1,712 ) (1,018 ) (188 ) — (3,441 ) Add back recoveries of loans previously charged-off 211 648 448 — — 1,307 Ending balance $ 32,281 $ 6,315 $ 39,995 $ 1,749 $ — $ 80,340 Six Months Ended June 30, 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 (20,140 ) 3,352 22,003 1,335 — 6,550 Less loans charged-off (2,445 ) (3,604 ) (1,506 ) (188 ) — (7,743 ) Add back recoveries of loans previously charged-off 2,570 1,423 723 — — 4,716 Ending balance $ 32,281 $ 6,315 $ 39,995 $ 1,749 $ — $ 80,340 As of December 31, 2016 Real Estate Consumer Commercial Agriculture Other Total Allowance for loan losses: Loans individually evaluated for impairment $ 4,588 $ — $ 9,254 $ 112 $ — $ 13,954 Loans collectively evaluated for impairment 24,037 7,711 28,838 1,674 — 62,260 Allowance for loan losses $ 28,625 $ 7,711 $ 38,092 $ 1,786 $ — $ 76,214 Loans held for investment: Individually evaluated for impairment $ 68,632 $ — $ 32,397 $ 3,662 $ — $ 104,691 Collectively evaluated for impairment 3,445,451 970,266 765,545 129,196 1,601 5,312,059 Total loans $ 3,514,083 $ 970,266 $ 797,942 $ 132,858 $ 1,601 $ 5,416,750

OREO (Tables)

OREO (Tables)	6 Months Ended
	Jun. 30, 2017
Repossessed Assets [Abstract]
Other Real Estate Owned Roll Forward	Information with respect to the Company's other real estate owned follows: Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Beginning balance $ 9,428 $ 9,257 $ 10,019 $ 6,254 OREO acquired through acquisition 1,055 — 1,055 — Additions 1,395 792 1,763 4,019 Valuation adjustments (9 ) (586 ) (56 ) (603 ) Dispositions (583 ) (1,555 ) (1,495 ) (1,762 ) Ending balance $ 11,286 $ 7,908 $ 11,286 $ 7,908 The carrying values of foreclosed residential real estate properties included in other real estate owned were $ 2,686 and $2,282 as of June 30, 2017 and December 31, 2016, 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 June 30, 2017 or December 31, 2016.

Derivatives and Hedging (Tables

Derivatives and Hedging (Tables)	6 Months Ended
	Jun. 30, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block]	June 30, 2017 December 31, 2016 Notional Amount Estimated Fair Value Notional Amount Estimated Fair Value Derivative Assets (included in other assets): Non-hedging interest rate derivatives: Interest rate swap contracts $ 320,809 $ 9,001 $ 53,593 $ 1,332 Interest rate lock commitments 64,673 1,301 73,422 1,131 Forward loan sales contracts 82,589 297 126,836 286 Total derivative assets $ 468,071 $ 10,599 $ 253,851 $ 2,749 Derivative Liabilities (included in accounts payable and accrued expenses): Derivatives designated as hedges: Interest rate swap contracts $ 100,000 $ 470 $ 100,000 $ 33 Non-hedging interest rate derivatives: Interest rate swap contracts 320,809 9,327 53,593 1,281 Total derivative liabilities $ 420,809 $ 9,797 $ 153,593 $ 1,314
Schedule of Derivative Instruments, Effect on Other Comprehensive Income (Loss) [Table Text Block]	Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Derivatives designated as hedges: Amount of loss recognized in other comprehensive income (effective portion) $ (486 ) $ (804 ) $ (437 ) $ (3,002 ) Non-hedging interest rate derivatives: Amount of gain (loss) recognized in other non-interest income 70 (50 ) 31 (79 ) Amount of net fee expense recognized in other non-interest income 321 245 279 245 Amount of net gains recognized in mortgage banking revenues 290 523 181 1,218

Earnings per Share (Tables)

Earnings per Share (Tables)	6 Months Ended
	Jun. 30, 2017
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 six month periods ended June 30, 2017 and 2016 : Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Net income $ 21,868 $ 25,554 $ 44,994 $ 45,678 Weighted average common shares outstanding for basic earnings per share computation 47,612,971 44,268,985 46,170,500 44,494,102 Dilutive effects of stock-based compensation 461,480 376,190 510,875 385,513 Weighted average common shares outstanding for diluted earnings per common share computation 48,074,451 44,645,175 46,681,375 44,879,615 Basic earnings per common share $ 0.46 $ 0.58 $ 0.97 $ 1.03 Diluted earnings per common share $ 0.45 $ 0.57 $ 0.96 $ 1.02 Anti-dilutive unvested time restricted stock 96,262 96,726 92,626 96,726

Regulatory Capital (Tables)

Regulatory Capital (Tables)	6 Months Ended
	Jun. 30, 2017
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 June 30, 2017 and December 31, 2016 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 June 30, 2017 Total risk-based capital: Consolidated $ 1,086,842 12.56 % $ 800,182 9.25 % $ 908,314 10.50 % $ 865,061 10.00 % FIB 824,454 13.00 586,642 9.25 665,918 10.50 634,208 10.00 BOTC 240,391 10.53 211,145 9.25 239,678 10.50 228,265 10.00 Tier 1 risk-based capital: Consolidated 1,011,141 11.69 627,169 7.25 735,302 8.50 692,049 8.00 FIB 748,753 11.81 459,801 7.25 539,077 8.50 507,366 8.00 BOTC 240,391 10.53 165,492 7.25 194,025 8.50 182,612 8.00 Common equity tier 1 risk-based capital: Consolidated 931,675 10.77 497,410 5.75 605,543 7.00 562,290 6.50 FIB 748,753 11.81 364,669 5.75 443,945 7.00 412,235 6.50 BOTC 240,391 10.53 131,252 5.75 159,786 7.00 148,372 6.50 Leverage capital ratio: Consolidated 1,011,141 10.65 379,616 4.00 379,616 4.00 474,519 5.00 FIB 748,753 8.67 345,442 4.00 345,442 4.00 431,803 5.00 BOTC 240,391 8.12 118,476 4.00 118,476 4.00 148,095 5.00 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, 2016 Total risk-based capital: Consolidated $ 974,488 15.13 % $ 555,665 8.63 % $ 676,070 10.50 % $ 643,876 10.00 % FIB 841,967 13.13 553,459 8.63 673,386 10.50 641,320 10.00 Tier 1 risk-based capital: Consolidated 894,273 13.89 426,890 6.63 547,295 8.50 $ 515,101 8.00 FIB 765,753 11.94 425,195 6.63 545,122 8.50 513,056 8.00 Common equity tier 1 risk-based capital: Consolidated 814,273 12.65 330,308 5.13 450,713 7.00 $ 418,519 6.50 FIB 765,753 11.94 328,997 5.13 448,924 7.00 416,858 6.50 Leverage capital ratio: Consolidated 894,273 10.11 353,838 4.00 353,838 4.00 $ 442,297 5.00 FIB 765,753 8.69 352,283 4.00 352,283 4.00 440,353 5.00 (1) The ratios for the well capitalized requirement are only applicable to FIB and BOTC. 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)	6 Months Ended
	Jun. 30, 2017
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 June 30, 2017 2016 2017 2016 2017 2016 Investment securities available-for sale: Change in net unrealized gains during period $ 8,006 $ 10,043 $ 3,298 $ 3,947 $ 4,708 $ 6,096 Reclassification adjustment for net (gains) losses included in net income (5 ) (108 ) (2 ) (42 ) (3 ) (66 ) Change in unamortized loss on available- for-sale securities transferred into held-to- maturity 464 452 191 170 273 282 Unrealized (gain) loss on derivatives (486 ) (804 ) (201 ) (305 ) (285 ) (499 ) Defined benefits post-retirement benefit plan: Change in net actuarial (gain) loss (176 ) 13 (72 ) 5 (104 ) 8 Total other comprehensive income $ 7,803 $ 9,596 $ 3,214 $ 3,775 $ 4,589 $ 5,821 Pre-tax Tax Expense (Benefit) Net of Tax Six Months Ended June 30, 2017 2016 2017 2016 2017 2016 Investment securities available-for sale: Change in net unrealized gains during period $ 17,365 $ 18,671 $ 6,985 $ 7,322 $ 10,380 $ 11,349 Reclassification adjustment for net gains included in net income (7 ) (87 ) (3 ) (34 ) (4 ) (53 ) Change in unamortized loss on available- for-sale securities transferred into held-to- maturity 929 904 374 340 555 564 Unrealized loss on derivatives (437 ) (3,002 ) (176 ) (1,141 ) (261 ) (1,861 ) Defined benefits post-retirement benefit plan: Change in net actuarial loss (914 ) 28 (368 ) 11 (546 ) 17 Total other comprehensive income $ 16,936 $ 16,514 $ 6,812 $ 6,498 $ 10,124 $ 10,016
Schedule of Accumulated Other Comprehensive Income (Loss)	The components of accumulated other comprehensive loss, net of related tax effects, are as follows: June 30, December 31, Net unrealized gain (loss) on investment securities available-for-sale $ 947 $ (10,143 ) Net realized gain (loss) on derivatives (434 ) (23 ) Net actuarial gain (loss) on defined benefit post-retirement benefit plans 1,483 2,038 Net accumulated other comprehensive gain (loss) $ 1,996 $ (8,128 )

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2017
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 June 30, 2017 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 $ 3,607 $ — $ 3,607 $ — Obligations of U.S. government agencies 675,318 — 675,318 — U.S. agencies mortgage-backed securities & collateralized mortgage obligations 1,222,937 — 1,222,937 — Private mortgage-backed securities 108,485 — 108,485 — Corporate securities 66,884 — 66,884 Other investments 2,963 — 2,963 — Loans held for sale 30,383 — 30,383 — Derivative assets: Interest rate swap contracts 9,001 — 9,001 — Interest rate lock commitments 1,301 — 1,301 — Forward loan sale contracts 297 — 297 — Derivative liabilities: Interest rate swap contracts 9,797 — 9,797 — Deferred compensation plan assets 11,598 — 11,598 — Deferred compensation plan liabilities 11,598 — 11,598 — Fair Value Measurements at Reporting Date Using As of December 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 $ 3,612 $ — $ 3,612 $ — Obligations of U.S. government agencies 391,297 — 391,297 — U.S. agencies mortgage-backed securities & collateralized mortgage obligations 1,213,701 — 1,213,701 — Private mortgage-backed securities 116 — 116 — Other investments 2,972 — 2,972 — Loans held for sale 61,794 — 61,794 — Derivative assets: Interest rate swap contracts 1,332 — 1,332 — Interest rate lock commitments 1,131 — 1,131 — Forward loan sales contracts 286 — 286 — Derivative liabilities Interest rate swap contracts 1,314 — 1,314 — Deferred compensation plan assets 10,627 — 10,627 — Deferred compensation plan liabilities 10,627 — 10,627 —
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 June 30, 2017 Balance Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Impaired loans $ 34,975 $ — $ — $ 34,975 Other real estate owned 1,422 — — 1,422 Long-lived assets to be disposed of by sale 356 — — 356 Fair Value Measurements at Reporting Date Using As of December 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 $ 39,344 $ — $ — $ 39,344 Other real estate owned 2,110 — — 2,110 Long-lived assets to be disposed of by sale 1,335 — — 1,335
Fair Value Inputs, Assets, Quantitative Information	Fair Value As of June 30, 2017 December 31, 2016 Valuation Technique Unobservable Inputs Range (Weighted Average) Impaired loans $ 34,975 $ 39,344 Appraisal Appraisal adjustment 0% - 66% (31%) Other real estate owned 1,422 2,110 Appraisal Appraisal adjustment 8% - 96% (18%) Long-lived assets to be disposed of by sale 356 1,335 Appraisal Appraisal adjustment 0% - 9% (6%)
Fair Value, by Balance Sheet Grouping	Fair Value Measurements at Reporting Date Using As of June 30, 2017 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 $ 919,775 $ 919,775 $ 919,775 $ — $ — Investment securities available-for-sale 2,080,194 2,080,194 — 2,080,194 — Investment securities held-to-maturity 529,442 535,145 — 535,145 — Accrued interest receivable 35,830 35,830 — 35,830 — Mortgage servicing rights, net 23,715 34,580 — 34,580 — Loans held for sale 30,383 30,383 — 30,383 — Net loans held for investment 7,449,889 7,325,012 — 7,290,037 34,975 Derivative assets 10,599 10,599 — 10,599 — Deferred compensation plan assets 11,598 11,598 — 11,598 — Total financial assets $ 11,091,425 $ 10,983,116 $ 919,775 $ 10,028,366 $ 34,975 Financial liabilities: Total deposits, excluding time deposits $ 8,817,211 $ 8,817,211 $ 8,817,211 $ — $ — Time deposits 1,202,789 1,195,454 — 1,195,454 — Securities sold under repurchase agreements 579,772 579,772 — 579,772 — Other borrowed funds 15,019 15,019 — 15,019 — Accrued interest payable 8,917 8,917 — 8,917 — Long-term debt 28,017 28,240 — 28,240 — Subordinated debentures held by subsidiary trusts 82,477 91,519 — 91,519 — Derivative liabilities 9,797 9,797 — 9,797 — Deferred compensation plan liabilities 11,598 11,598 — 11,598 — Total financial liabilities $ 10,755,597 $ 10,757,527 $ 8,817,211 $ 1,940,316 $ — Fair Value Measurements at Reporting Date Using As of December 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 $ 782,023 $ 782,023 $ 782,023 $ — $ — Investment securities available-for-sale 1,611,698 1,611,698 — 1,611,698 — Investment securities held-to-maturity 512,770 513,273 — 513,273 — Accrued interest receivable 29,852 29,852 — 29,852 — Mortgage servicing rights, net 18,457 35,656 — 35,656 — Loans held for sale 61,794 61,794 — 61,794 Net loans held for investment 5,340,536 5,248,127 — 5,208,783 39,344 Derivative assets 2,749 2,749 — 2,749 — Deferred compensation plan assets 10,627 10,627 — 10,627 — Total financial assets $ 8,370,506 $ 8,295,799 $ 782,023 $ 7,474,432 $ 39,344 Financial liabilities: Total deposits, excluding time deposits $ 6,324,512 $ 6,324,512 $ 6,324,512 $ — $ — Time deposits 1,051,598 1,044,670 — 1,044,670 — Securities sold under repurchase agreements 537,556 537,556 — 537,556 — Other borrowed funds 6 6 — 6 — Accrued interest payable 5,421 5,421 — 5,421 — Long-term debt 27,970 27,477 — 27,477 — Subordinated debentures held by subsidiary trusts 82,477 73,554 — 73,554 — Derivative liabilities 1,314 1,314 — 1,314 — Deferred compensation plan liabilities 10,627 10,627 — 10,627 — Total financial liabilities $ 8,041,481 $ 8,025,137 $ 6,324,512 $ 1,700,625 $ —

Business Combination (Details)

Business Combination (Details) $ / shares in Units, shares in Thousands	May 30, 2017USD ($)$ / shares	Nov. 17, 2016	Jun. 30, 2017USD ($)shares	Jun. 30, 2017USD ($)$ / sharesshares	Jun. 30, 2016USD ($)$ / shares	Jun. 30, 2017USD ($)$ / sharesshares	Jun. 30, 2016USD ($)$ / shares	Dec. 31, 2016USD ($)
Business Acquisition [Line Items]
Cash paid related to Cascade Options						$ 9,300,000
Cash paid for Cascade unvested restricted stock			$ 2,200,000	$ 2,200,000		$ 2,200,000
Shares issued for Cascade unvested restricted stock | shares			168	168		168
Finite-lived Intangible Assets Acquired				$ 47,950,000	$ 0	$ 47,950,000	$ 0
Business Acquisition, Pro Forma Interest Income				103,248,000	94,698,000	203,326,000	189,772,000
Loans Acquired in Transfer, Contractually Required Payments Receivable at Acquisition			$ 2,098,155,000	2,098,155,000		2,098,155,000
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, Contractually Required Payments Receivable at Acquisition			48,041,000	48,041,000		48,041,000
Business Acquisition, Effective Date of Acquisition	May 30, 2017
Business Acquisition Conversion Rate	$ 1.91
Assets			12,236,342,000	12,236,342,000		12,236,342,000		$ 9,063,895,000
Deposits			10,020,000,000	10,020,000,000		10,020,000,000		7,376,110,000
Certain Loans Acquired in Transfer, Nonaccretable Difference			23,376,000	23,376,000		23,376,000
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, Cash Flows Expected to be Collected at Acquisition			24,665,000	24,665,000		24,665,000
Certain Loans Acquired in Transfer, Accretable Yield			1,901,000	1,901,000		1,901,000
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value			22,764,000	22,764,000		22,764,000
Loans Acquired in Transfer, Nonaccretable Difference			23,387,000	23,387,000		23,387,000
Loans Acquired in Transfer at Acquisition Fair Value			2,067,572,000	2,067,572,000		2,067,572,000
Business Acquisition, Pro Forma Non Interest Income				41,314,000	44,780,000	77,897,000	78,286,000
Business Acquisition, Pro Forma Revenue				144,562,000	139,478,000	281,223,000	268,058,000
Business Acquisition, Pro Forma Net Income (Loss)				$ 29,409,000	$ 29,534,000	$ 58,709,000	$ 23,716,000
Business Acquisition, Pro Forma Earnings Per Share, Basic | $ / shares				$ 0.50	$ 0.53	$ 1.02	$ 0.43
Business Acquisition, Pro Forma Earnings Per Share, Diluted | $ / shares				$ 500	$ 530	$ 1,010	$ 420
Non-core acquisition expenses				$ 10,133,000	$ 0	$ 10,838,000	$ 0
Professional Fees included in Acquisition Expense				5,926		6,542
Business Acquisition, Share Price | $ / shares	$ 34.30
Expense related to restricted awards excluded from consideration						2,400,000
Restricted stock expense included in consideration						5,500,000
Goodwill			$ 444,327,000	$ 444,327,000		$ 444,327,000		$ 212,820,000
Bank of the Cascades [Member]
Business Acquisition [Line Items]
Number of banking offices			46	46		46
Cascade Bank Acquisition, as Recorded by the Company [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	$ 155,029,000
Business Combination, Consideration Transferred	540,998,000
Goodwill	$ 231,507,000
Flathead Bank [Member]
Business Acquisition [Line Items]
Business Acquisition, Date of Acquisition Agreement		Nov. 17, 2016
Bank of the Cascades [Member]
Business Acquisition [Line Items]
Business Acquisition, Revenue Reported by Acquired Entity for Reported Period			$ 12.9
Business Acquisition, Net Income Reported by Acquired Entity for Reported Period			3
Goodwill			$ 231,500	$ 231,500		$ 231,500
Bank of the Cascades [Member] | Class A Common Stock
Business Acquisition [Line Items]
Business Acquisition Conversion Share Rate | $ / shares	$ 0.14864
Bank of the Cascades [Member] | Core Deposits [Member]
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired						$ 47,950,000
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life						10 years

Acquisitions Schedule of Recogn

Acquisitions Schedule of Recognized Identifiable Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands		May 30, 2017	Jun. 30, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Business Acquisition, Equity Interest Issued or Issuable, Value Assigned		$ 385,969	$ 385,969
Goodwill			$ 444,327	$ 212,820
Cascade Bank Acquisition, as recorded by Cascade Bank [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents		246,804
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Marketable Securities		476,733
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets		3,015,571
Business Combinations, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Asset		32,232
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Assets		113,915
Business Combinations, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Real Estate Owned		1,268
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles		0
Business Combinations, Recognized Identifiable Assets Acquired and Liabilities Assumed, Loans Held for Investment		2,111,786
Business Combinations, Recognized Identifiable Assets Acquired and Liabilities Assumed, Loans Held for Sale		10,253
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Loans and Leases Receivable, Allowance		23,974
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment		46,554
Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed, Deposits		2,669,910
Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed, Other Liabilities		62,150
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities		2,732,060
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net		283,511
Cascade Bank Acquisition, Fair Value Adjustments [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents		0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Marketable Securities	[1]	4,876
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets		25,454
Business Combinations, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Asset	[2]	(22,336)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Assets	[3]	1,378
Business Combinations, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Real Estate Owned		0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	[4]	47,950
Business Combinations, Recognized Identifiable Assets Acquired and Liabilities Assumed, Loans Held for Investment	[5]	(31,703)
Business Combinations, Recognized Identifiable Assets Acquired and Liabilities Assumed, Loans Held for Sale		0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Loans and Leases Receivable, Allowance	[6]	(23,974)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment	[7]	1,315
Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed, Deposits		(934)
Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed, Other Liabilities		408
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities		(526)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net		24,928
Cascade Bank Acquisition, as Recorded by the Company [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents		246,804
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Marketable Securities		481,609
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets		3,041,025
Payments to Acquire Businesses, Gross		155,029
Business Combinations, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Asset		9,896
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Assets		115,293
Business Combinations, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Real Estate Owned		1,268
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles		47,950
Business Combinations, Recognized Identifiable Assets Acquired and Liabilities Assumed, Loans Held for Investment		2,080,083
Business Combinations, Recognized Identifiable Assets Acquired and Liabilities Assumed, Loans Held for Sale		10,253
Business Combination, Consideration Transferred		540,998
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Loans and Leases Receivable, Allowance		0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment		47,869
Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed, Deposits		2,668,976
Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed, Other Liabilities		62,558
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities		2,731,534
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net		309,491
Goodwill		$ 231,507
[1]	Write up of the book value of investments to their estimated fair values on the date of acquisition based upon quotes obtained from an independent third party pricing service.
[2]	Adjustment consists of the write-off of pre-existing deferred tax assets as a result of the acquisition.
[3]	Adjustment consists of mortgage servicing rights assets as a result of the acquisition.(8) Decrease in book value of time deposits to their estimated fair values based upon interest rates of similar time deposits with similar terms on the date of acquisition based upon valuation from an independent accounting and advisory firm. (9) Increase in fair value due to credit card incentive program and swap liability offset.
[4]	Adjustment represents the value of the core deposit base assumed in the acquisition based upon valuation from an independent accounting and advisory firm.
[5]	Write down of the book value of loans to their estimated fair values. Shared National Credits (SNC) were recorded at quoted sales prices where available. The fair value of the remaining loans was estimated using cash flow projections based on the remaining maturity and repricing terms, adjusted for estimated future credit losses and prepayments and discounted to present value using a risk-adjusted market rate for similar loans. The fair value of collateral dependent loans acquired with deteriorated credit quality was estimated based on the Company's analysis of the fair value of each loan's underlying collateral, discounted using market-derived rates of return with consideration given to the period of time and costs associated with foreclosure and disposition of the collateral.
[6]	Adjustment to remove the Cascade allowance for loan losses at acquisition date, as the credit risk is accounted for in the fair value adjustment for loans receivable described in (2) above.
[7]	Write up of the book value of premises and equipment to their estimated fair values on the date of acquisition based upon appraisals obtained from an independent third party appraiser or broker's opinion of value.

Acquisitions Pro Forma (Details

Acquisitions Pro Forma (Details)	6 Months Ended
	Jun. 30, 2017USD ($)
Business Acquisition [Line Items]
Control Costs, Legal and Professional Fees included in Acquisition-Related Costs	$ 11,195

Goodwill and intangibles (Detai

Goodwill and intangibles (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2015
Goodwill [Line Items]
Goodwill	$ 444,327,000		$ 444,327,000			$ 212,820,000
Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year	2,597,000		2,597,000
Finite-Lived Intangible Assets, Net	52,837,000	$ 8,935,000	52,837,000	$ 8,935,000	$ 9,018,000	$ 9,648,000	$ 9,762,000	$ 10,589,000
Finite-lived Intangible Assets Acquired	47,950,000	0	47,950,000	0
Finite-Lived Intangible Assets, Period Increase (Decrease)	(3,069,000)	0	(3,069,000)	0
Core deposit intangibles amortization	(1,062,000)	$ (827,000)	(1,692,000)	$ (1,654,000)
Finite-Lived Intangible Assets, Amortization Expense, Year Two	5,093,000		5,093,000
Finite-Lived Intangible Assets, Amortization Expense, Year Three	4,994,000		4,994,000
Finite-Lived Intangible Assets, Amortization Expense, Year Four	4,872,000		4,872,000
Finite-Lived Intangible Assets, Amortization Expense, Year Five	4,729,000		4,729,000
Finite-Lived Intangible Assets, Amortization Expense, after Year Five	22,164,000		22,164,000
Goodwill, Impairment Loss			0
Bank of the Cascades [Member]
Goodwill [Line Items]
Goodwill	$ 231,500		$ 231,500

Amortized Cost and Approximate

Amortized Cost and Approximate Fair Values of Investment Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Available-for-Sale:
Available-for-Sale, Amortized Cost	$ 2,076,114	$ 1,624,976
Available-for-sale Securities, Gross Unrealized Gain1	11,971	6,782
Available-for-sale Securities, Gross Unrealized Loss1	(7,891)	(20,060)
Available-for-Sale, Estimated Fair Value	2,080,194	1,611,698
Held-to-Maturity:
Held-to-Maturity, Amortized Cost	529,442	512,770
Held-to-maturity Securities, Gross Unrealized Gain1	15,248	10,667
Held-to-maturity Securities, Gross Unrealized Loss1	(9,545)	(10,164)
Held-to-Maturity, Estimated Fair Value	535,145	513,273
US Treasury Securities [Member]
Available-for-Sale:
Available-for-Sale, Amortized Cost	3,607	3,608
Available-for-sale Securities, Gross Unrealized Gain1	2	5
Available-for-sale Securities, Gross Unrealized Loss1	(2)	(1)
Available-for-Sale, Estimated Fair Value	3,607	3,612
Obligations of U.S. government agencies
Available-for-Sale:
Available-for-Sale, Amortized Cost	676,485	397,411
Available-for-sale Securities, Gross Unrealized Gain1	1,647	343
Available-for-sale Securities, Gross Unrealized Loss1	(2,814)	(6,457)
Available-for-Sale, Estimated Fair Value	675,318	391,297
Held-to-Maturity:
Held-to-Maturity, Amortized Cost	19,737	19,737
Held-to-maturity Securities, Gross Unrealized Gain1	28	0
Held-to-maturity Securities, Gross Unrealized Loss1	(5)	(162)
Held-to-Maturity, Estimated Fair Value	19,760	19,575
U.S. agency residential mortgage-backed securities & collateralized mortgage obligations
Available-for-Sale:
Available-for-Sale, Amortized Cost	1,217,701	1,220,890
Available-for-sale Securities, Gross Unrealized Gain1	10,001	6,412
Available-for-sale Securities, Gross Unrealized Loss1	(4,765)	(13,601)
Available-for-Sale, Estimated Fair Value	1,222,937	1,213,701
Held-to-Maturity:
Held-to-Maturity, Amortized Cost	268,218	279,578
Held-to-maturity Securities, Gross Unrealized Gain1	10,714	7,804
Held-to-maturity Securities, Gross Unrealized Loss1	(9,360)	(9,249)
Held-to-Maturity, Estimated Fair Value	269,572	278,133
Private mortgage-backed securities
Available-for-Sale:
Available-for-Sale, Amortized Cost	108,577	116
Available-for-sale Securities, Gross Unrealized Gain1	212	1
Available-for-sale Securities, Gross Unrealized Loss1	(304)	(1)
Available-for-Sale, Estimated Fair Value	108,485	116
State, county and municipal securities
Held-to-Maturity:
Held-to-Maturity, Amortized Cost	188,486	160,192
Held-to-maturity Securities, Gross Unrealized Gain1	4,172	2,723
Held-to-maturity Securities, Gross Unrealized Loss1	(141)	(542)
Held-to-Maturity, Estimated Fair Value	192,517	162,373
Corporate securities
Available-for-Sale:
Available-for-Sale, Amortized Cost	66,793
Available-for-sale Securities, Gross Unrealized Gain1	97
Available-for-sale Securities, Gross Unrealized Loss1	(6)
Available-for-Sale, Estimated Fair Value	66,884
Held-to-Maturity:
Held-to-Maturity, Amortized Cost	52,804	53,032
Held-to-maturity Securities, Gross Unrealized Gain1	333	139
Held-to-maturity Securities, Gross Unrealized Loss1	(39)	(211)
Held-to-Maturity, Estimated Fair Value	53,098	52,960
Other Investments
Held-to-Maturity:
Held-to-Maturity, Amortized Cost	197	231
Held-to-maturity Securities, Gross Unrealized Gain1	1	1
Held-to-maturity Securities, Gross Unrealized Loss1	0	0
Held-to-Maturity, Estimated Fair Value	198	232
Other Investments
Available-for-Sale:
Available-for-Sale, Amortized Cost	2,951	2,951
Available-for-sale Securities, Gross Unrealized Gain1	12	21
Available-for-sale Securities, Gross Unrealized Loss1	0	0
Available-for-Sale, Estimated Fair Value	$ 2,963	$ 2,972

Investment Securities Realized

Investment Securities Realized Gains (Losses) on Investments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Investments, Debt and Equity Securities [Abstract]
Gross realized gains	$ 5	$ 108	$ 7	$ 165
Gross realized losses	$ 0	$ 0	$ 0	$ (78)

Investment Securities Gross Unr

Investment Securities Gross Unrealized Losses and Fair Values of Investment Securities (Details) $ in Thousands	Jun. 30, 2017USD ($)securities	Dec. 31, 2016USD ($)securities
Available-for-Sale:
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 970,913	$ 1,063,374
Available-for-sale Securities, Continuous Unrealized Loss Position, Less Than 12 months, Aggregate Loss1	(7,461)	(19,560)
Available-for-Sale, 12 Months or More Fair Value	31,879	15,849
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 months or Longer, Aggregate Loss1	(430)	(500)
Available-for-Sale, Total Fair Value	1,002,792	1,079,223
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss1	(7,891)	(20,060)
Held-to-Maturity:
Held-to-Maturity, Less than 12 Months Fair Value	88,499	203,424
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less Than 12 months, Aggregate Loss1	(8,252)	(8,879)
Held-to-Maturity, 12 Months or More Fair Value	18,650	22,817
Held-to-Maturity, 12 Months or More Gross Unrealized Losses	(1,293)	(1,285)
Held-to-Maturity, Total Fair Value	107,149	226,241
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss1	$ (9,545)	$ (10,164)
Available-for-Sale and Held-to-Maturity:
Investment Securities in an Unrealized Loss Position (Number of Securities) | securities	337	396
US Treasury Securities [Member]
Available-for-Sale:
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 1,797	$ 598
Available-for-sale Securities, Continuous Unrealized Loss Position, Less Than 12 months, Aggregate Loss1	(2)	(1)
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	1,797	598
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss1	(2)	(1)
Obligations of U.S. government agencies
Available-for-Sale:
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	359,889	316,511
Available-for-sale Securities, Continuous Unrealized Loss Position, Less Than 12 months, Aggregate Loss1	(2,804)	(6,457)
Available-for-Sale, 12 Months or More Fair Value	9,989	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 months or Longer, Aggregate Loss1	(10)	0
Available-for-Sale, Total Fair Value	369,878	316,511
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss1	(2,814)	(6,457)
Held-to-Maturity:
Held-to-Maturity, Less than 12 Months Fair Value	9,985	19,575
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less Than 12 months, Aggregate Loss1	(5)	(162)
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	9,985	19,575
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss1	(5)	(162)
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	599,643	746,265
Available-for-sale Securities, Continuous Unrealized Loss Position, Less Than 12 months, Aggregate Loss1	(4,346)	(13,102)
Available-for-Sale, 12 Months or More Fair Value	21,848	15,801
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 months or Longer, Aggregate Loss1	(419)	(499)
Available-for-Sale, Total Fair Value	621,491	762,066
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss1	(4,765)	(13,601)
Held-to-Maturity:
Held-to-Maturity, Less than 12 Months Fair Value	42,109	108,857
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less Than 12 months, Aggregate Loss1	(8,069)	(7,973)
Held-to-Maturity, 12 Months or More Fair Value	17,766	19,986
Held-to-Maturity, 12 Months or More Gross Unrealized Losses	(1,291)	(1,276)
Held-to-Maturity, Total Fair Value	59,875	128,843
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss1	(9,360)	(9,249)
Private mortgage-backed securities
Available-for-Sale:
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	1,484	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Less Than 12 months, Aggregate Loss1	(303)	0
Available-for-Sale, 12 Months or More Fair Value	42	48
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 months or Longer, Aggregate Loss1	(1)	(1)
Available-for-Sale, Total Fair Value	1,526	48
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss1	(304)	(1)
State, county and municipal securities
Held-to-Maturity:
Held-to-Maturity, Less than 12 Months Fair Value	21,331	42,518
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less Than 12 months, Aggregate Loss1	(139)	(533)
Held-to-Maturity, 12 Months or More Fair Value	884	2,831
Held-to-Maturity, 12 Months or More Gross Unrealized Losses	(2)	(9)
Held-to-Maturity, Total Fair Value	22,215	45,349
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss1	(141)	(542)
Corporate securities
Available-for-Sale:
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	8,100
Available-for-sale Securities, Continuous Unrealized Loss Position, Less Than 12 months, Aggregate Loss1	(6)
Available-for-Sale, 12 Months or More Fair Value	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 months or Longer, Aggregate Loss1	0
Available-for-Sale, Total Fair Value	8,100
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss1	(6)
Held-to-Maturity:
Held-to-Maturity, Less than 12 Months Fair Value	15,074	32,474
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less Than 12 months, Aggregate Loss1	(39)	(211)
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	15,074	32,474
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss1	$ (39)	$ (211)

Maturities of Investment Securi

Maturities of Investment Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity
Available-for-Sale Amortized Cost, Within One Year	$ 371,218
Available-for-Sale Amortized Cost, After One Year but Within Five Years	1,227,734
Available-for-Sale Amortized Cost, After Five Years but Within Ten Years	228,192
Available-for-Sale Amortized Cost, After Ten Years	248,970
Available-for-Sale, Amortized Cost	2,076,114	$ 1,624,976
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity
Available-for-Sale Estimated Fair Value, Within One Year	372,541
Available-for-Sale Estimated Fair Value, After One Year but Within Five Years	1,229,254
Available-for-Sale Estimated Fair Value, After Ten Years	228,561
Available-for-Sale Estimated Fair Value, After Five Years but Within Ten Years	249,838
Available-for-Sale, Estimated Fair Value	2,080,194	1,611,698
Held-to-maturity Securities, Debt Maturities, Net Carrying Amount
Held-to-Maturity Amortized Cost, Within One Year	75,748
Held-to-Maturity Amortized Cost, After One Year but Within Five Years	268,855
Held-to-Maturity Amortized Cost, After Five Years but Within Ten Years	133,245
Held-to-Maturity Amortized Cost, After Ten Years	51,594
Held-to-Maturity, Amortized Cost	529,442	512,770
Held-to-maturity Securities, Debt Maturities, Fair Value, Rolling Maturity
Held-to-Maturity Estimated Fair Value, Within One Year	74,416
Held-to-Maturity Estimated Fair Value, After One Year but Within Five Years	280,504
Held-to-Maturity Estimated Fair Value, After Five Years but Within Ten Years	134,858
Held-to-Maturity Estimated Fair Value, After Ten Years	45,367
Held-to-Maturity, Estimated Fair Value	535,145	$ 513,273
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	63,743
Investment Securities Primarily Classified as Available-for-Sale, Fair Value, After One Year but Within Five Years	$ 63,933

Schedule of Loans by Class (Det

Schedule of Loans by Class (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Loans and Leases Receivable [Line Items]
Loans held for investment	$ 7,525,590	$ 5,416,750
Mortgage loans held for sale	30,383	61,794
Total loans	7,555,973	5,478,544
Commercial real estate
Loans and Leases Receivable [Line Items]
Loans held for investment	2,816,526	1,834,445
Land acquisition & development construction real estate
Loans and Leases Receivable [Line Items]
Loans held for investment	339,884	208,512
Residential construction real estate
Loans and Leases Receivable [Line Items]
Loans held for investment	219,756	147,896
Commercial construction real estate
Loans and Leases Receivable [Line Items]
Loans held for investment	121,605	125,589
Total construction loans
Loans and Leases Receivable [Line Items]
Loans held for investment	681,245	481,997
Residential real estate
Loans and Leases Receivable [Line Items]
Loans held for investment	1,466,014	1,027,393
Agricultural real estate
Loans and Leases Receivable [Line Items]
Loans held for investment	163,175	170,248
Total real estate loans
Loans and Leases Receivable [Line Items]
Loans held for investment	5,126,960	3,514,083
Indirect consumer
Loans and Leases Receivable [Line Items]
Loans held for investment	779,026	752,409
Other consumer
Loans and Leases Receivable [Line Items]
Loans held for investment	175,737	148,087
Credit card consumer
Loans and Leases Receivable [Line Items]
Loans held for investment	75,631	69,770
Total consumer loans
Loans and Leases Receivable [Line Items]
Loans held for investment	1,030,394	970,266
Commercial
Loans and Leases Receivable [Line Items]
Loans held for investment	1,210,869	797,942
Agricultural
Loans and Leases Receivable [Line Items]
Loans held for investment	149,129	132,858
Other, including overdrafts
Loans and Leases Receivable [Line Items]
Loans held for investment	$ 8,238	$ 1,601

Schedule of Recorded Investment

Schedule of Recorded Investment in Past Due Loans by Class (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Mortgage loans held for sale	$ 30,383		$ 30,383		$ 61,794
Loans held for investment	7,525,590		7,525,590		5,416,750
Total loans	7,555,973		7,555,973		5,478,544
Interest Income on Non-Accrual Loans if Accrued	919	$ 821	1,772	$ 1,690
Commercial real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	5,919		5,919		8,709
Current Loans	2,780,010		2,780,010		1,799,525
Non-accrual Loans	30,597		30,597		26,211
Loans held for investment	2,816,526		2,816,526		1,834,445
Land acquisition & development construction real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	1,974		1,974		1,264
Current Loans	333,247		333,247		202,223
Non-accrual Loans	4,663		4,663		5,025
Loans held for investment	339,884		339,884		208,512
Residential construction real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	1,632		1,632		1,195
Current Loans	217,914		217,914		146,245
Non-accrual Loans	210		210		456
Loans held for investment	219,756		219,756		147,896
Commercial construction real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	0		0		0
Current Loans	117,287		117,287		124,827
Non-accrual Loans	4,318		4,318		762
Loans held for investment	121,605		121,605		125,589
Total construction loans
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	3,606		3,606		2,459
Current Loans	668,448		668,448		473,295
Non-accrual Loans	9,191		9,191		6,243
Loans held for investment	681,245		681,245		481,997
Residential real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	20,302		20,302		5,968
Current Loans	1,441,507		1,441,507		1,014,990
Non-accrual Loans	4,205		4,205		6,435
Loans held for investment	1,466,014		1,466,014		1,027,393
Agricultural real estate
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	3,932		3,932		628
Current Loans	156,898		156,898		165,293
Non-accrual Loans	2,345		2,345		4,327
Loans held for investment	163,175		163,175		170,248
Total real estate loans
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	33,759		33,759		17,764
Current Loans	5,046,863		5,046,863		3,453,103
Non-accrual Loans	46,338		46,338		43,216
Loans held for investment	5,126,960		5,126,960		3,514,083
Indirect consumer
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	8,237		8,237		11,466
Current Loans	769,361		769,361		740,163
Non-accrual Loans	1,428		1,428		780
Loans held for investment	779,026		779,026		752,409
Other consumer
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	1,634		1,634		1,724
Current Loans	173,713		173,713		146,006
Non-accrual Loans	390		390		357
Loans held for investment	175,737		175,737		148,087
Credit card consumer
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	1,330		1,330		1,404
Current Loans	74,300		74,300		68,366
Non-accrual Loans	1		1		0
Loans held for investment	75,631		75,631		69,770
Total consumer loans
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	11,201		11,201		14,594
Current Loans	1,017,374		1,017,374		954,535
Non-accrual Loans	1,819		1,819		1,137
Loans held for investment	1,030,394		1,030,394		970,266
Commercial
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	6,419		6,419		4,632
Current Loans	1,178,688		1,178,688		767,878
Non-accrual Loans	25,762		25,762		25,432
Loans held for investment	1,210,869		1,210,869		797,942
Agricultural
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	2,537		2,537		1,894
Current Loans	143,824		143,824		127,956
Non-accrual Loans	2,768		2,768		3,008
Loans held for investment	149,129		149,129		132,858
Other, including overdrafts
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	0		0		312
Current Loans	8,238		8,238		1,289
Non-accrual Loans	0		0		0
Loans held for investment	8,238		8,238		1,601
Loans held for investment
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	53,916		53,916		39,196
Current Loans	7,394,987		7,394,987		5,304,761
Non-accrual Loans	76,687		76,687		72,793
Loans held for investment	7,525,590		7,525,590		5,416,750
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		0
Current Loans	30,383		30,383		61,794
Non-accrual Loans	0		0		0
Total loans
Loans and Leases Receivable Recorded Investment, Past Due [Line Items]
Total Loans 30 or More Days Past Due	53,916		53,916		39,196
Current Loans	7,425,370		7,425,370		5,366,555
Non-accrual Loans	76,687		76,687		72,793
Total loans	7,555,973		7,555,973		5,478,544
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	4,522		4,522		7,307
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	1,880		1,880		633
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	1,124		1,124		931
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	0		0		0
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	3,004		3,004		1,564
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	14,136		14,136		3,986
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	1,371		1,371		341
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	23,033		23,033		13,198
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	6,430		6,430		8,425
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	1,246		1,246		1,322
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	488		488		504
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	8,164		8,164		10,251
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	3,487		3,487		3,171
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	1,618		1,618		1,518
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		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	36,302		36,302		28,138
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		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	36,302		36,302		28,138
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	419		419		1,099
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	42		42		352
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	508		508		264
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		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	550		550		616
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	2,583		2,583		1,280
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	661		661		287
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	4,213		4,213		3,282
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	1,648		1,648		2,329
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	301		301		235
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	355		355		333
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	2,304		2,304		2,897
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	1,248		1,248		727
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	487		487		362
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	0		0		1
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	8,252		8,252		7,269
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		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	8,252		8,252		7,269
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	978		978		303
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	52		52		279
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		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		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	52		52		279
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	3,583		3,583		702
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	1,900		1,900		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	6,513		6,513		1,284
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	159		159		712
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	87		87		167
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	487		487		567
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	733		733		1,446
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	1,684		1,684		734
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	432		432		14
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	0		0		311
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	9,362		9,362		3,789
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		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	$ 9,362		$ 9,362		$ 3,789

Loans Schedule of Loans Acquire

Loans Schedule of Loans Acquired from Business Combinations (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Jun. 30, 2016
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities [Abstract]
Outstanding Balance	$ 60,195	$ 31,979
Carrying Amount Net, Accrual Status	39,359	20,140
Total Carrying Value	$ 39,359	$ 20,140

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		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Beginning Balance	$ 6,432	$ 6,678	$ 6,803	$ 6,713
Additions	1,929	0	1,929	0
Accretion Income	(668)	(615)	(1,273)	(1,229)
Reductions Due to Exit Events	(418)	(158)	(988)	(305)
Reclassifications from (to) nonaccretable differences	375	0	1,179	726
Ending Balance	$ 7,650	$ 5,905	$ 7,650	$ 5,905

Loans Schedule of Recorded Inve

Loans Schedule of Recorded Investment in Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Impaired Financing Receivable, Unpaid Principal Balance
Unpaid Total Principal Balance	$ 122,901		$ 122,901		$ 132,785
Recorded Investment With No Allowance	48,907		48,907		57,992
Recorded Investment With Allowance	48,324		48,324		46,699
Total Recorded Investment	97,231		97,231		104,691
Related Allowance	16,316		16,316		13,954
Impaired Financing Receivable, Average Recorded Investment and Cash Basis Method Interest Income
Average Recorded Investment	97,492	$ 81,121	100,963	$ 84,122
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Income Recognized	171	162	398	222
Interest Income on Impaired Loans If Interest Had Been Accrued	919	964	1,772	2,020
Commercial real estate
Impaired Financing Receivable, Unpaid Principal Balance
Unpaid Total Principal Balance	53,576		53,576		57,017
Recorded Investment With No Allowance	22,751		22,751		24,410
Recorded Investment With Allowance	20,380		20,380		21,420
Total Recorded Investment	43,131		43,131		45,830
Related Allowance	5,158		5,158		2,847
Impaired Financing Receivable, Average Recorded Investment and Cash Basis Method Interest Income
Average Recorded Investment	43,871	34,576	44,481	36,342
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Income Recognized	102	105	227	141
Land acquisition & development construction real estate
Impaired Financing Receivable, Unpaid Principal Balance
Unpaid Total Principal Balance	11,281		11,281		12,084
Recorded Investment With No Allowance	3,639		3,639		4,330
Recorded Investment With Allowance	1,718		1,718		1,813
Total Recorded Investment	5,357		5,357		6,143
Related Allowance	741		741		826
Impaired Financing Receivable, Average Recorded Investment and Cash Basis Method Interest Income
Average Recorded Investment	5,411	7,096	5,750	7,277
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Income Recognized	4	12	8	19
Residential construction real estate
Impaired Financing Receivable, Unpaid Principal Balance
Unpaid Total Principal Balance	312		312		1,555
Recorded Investment With No Allowance	209		209		219
Recorded Investment With Allowance	0		0		619
Total Recorded Investment	209		209		838
Related Allowance	0		0		1
Impaired Financing Receivable, Average Recorded Investment and Cash Basis Method Interest Income
Average Recorded Investment	212	277	524	282
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Income Recognized	0	0	0	0
Commercial construction real estate
Impaired Financing Receivable, Unpaid Principal Balance
Unpaid Total Principal Balance	4,728		4,728		4,786
Recorded Investment With No Allowance	226		226		3,940
Recorded Investment With Allowance	4,204		4,204		647
Total Recorded Investment	4,430		4,430		4,587
Related Allowance	2,828		2,828		657
Impaired Financing Receivable, Average Recorded Investment and Cash Basis Method Interest Income
Average Recorded Investment	4,463	1,421	4,509	1,433
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Income Recognized	1	2	44	2
Total construction loans
Impaired Financing Receivable, Unpaid Principal Balance
Unpaid Total Principal Balance	16,321		16,321		18,425
Recorded Investment With No Allowance	4,074		4,074		8,489
Recorded Investment With Allowance	5,922		5,922		3,079
Total Recorded Investment	9,996		9,996		11,568
Related Allowance	3,569		3,569		1,484
Impaired Financing Receivable, Average Recorded Investment and Cash Basis Method Interest Income
Average Recorded Investment	10,086	8,794	10,783	8,992
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Income Recognized	5	14	52	21
Residential real estate
Impaired Financing Receivable, Unpaid Principal Balance
Unpaid Total Principal Balance	7,636		7,636		8,222
Recorded Investment With No Allowance	4,472		4,472		4,074
Recorded Investment With Allowance	2,022		2,022		2,470
Total Recorded Investment	6,494		6,494		6,544
Related Allowance	170		170		253
Impaired Financing Receivable, Average Recorded Investment and Cash Basis Method Interest Income
Average Recorded Investment	6,574	3,067	6,519	4,138
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Income Recognized	4	2	8	3
Agricultural real estate
Impaired Financing Receivable, Unpaid Principal Balance
Unpaid Total Principal Balance	2,752		2,752		5,069
Recorded Investment With No Allowance	2,549		2,549		4,509
Recorded Investment With Allowance	153		153		181
Total Recorded Investment	2,702		2,702		4,690
Related Allowance	9		9		4
Impaired Financing Receivable, Average Recorded Investment and Cash Basis Method Interest Income
Average Recorded Investment	2,389	5,857	3,696	5,671
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Income Recognized	0	0	0	1
Total real estate loans
Impaired Financing Receivable, Unpaid Principal Balance
Unpaid Total Principal Balance	80,285		80,285		88,733
Recorded Investment With No Allowance	33,846		33,846		41,482
Recorded Investment With Allowance	28,477		28,477		27,150
Total Recorded Investment	62,323		62,323		68,632
Related Allowance	8,906		8,906		4,588
Impaired Financing Receivable, Average Recorded Investment and Cash Basis Method Interest Income
Average Recorded Investment	62,920	52,294	65,479	55,143
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Income Recognized	111	121	287	166
Total consumer loans
Impaired Financing Receivable, Unpaid Principal Balance
Unpaid Total Principal Balance	28		28
Recorded Investment With No Allowance	0		0
Recorded Investment With Allowance	25		25
Total Recorded Investment	25		25
Related Allowance	0		0
Impaired Financing Receivable, Average Recorded Investment and Cash Basis Method Interest Income
Average Recorded Investment	13	0	13	0
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Income Recognized	0	0	0	0
Commercial
Impaired Financing Receivable, Unpaid Principal Balance
Unpaid Total Principal Balance	39,587		39,587		40,314
Recorded Investment With No Allowance	13,021		13,021		13,230
Recorded Investment With Allowance	18,882		18,882		19,167
Total Recorded Investment	31,903		31,903		32,397
Related Allowance	6,882		6,882		9,254
Impaired Financing Receivable, Average Recorded Investment and Cash Basis Method Interest Income
Average Recorded Investment	32,491	28,074	32,150	28,133
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Income Recognized	60	41	109	56
Agricultural
Impaired Financing Receivable, Unpaid Principal Balance
Unpaid Total Principal Balance	3,001		3,001		3,738
Recorded Investment With No Allowance	2,040		2,040		3,280
Recorded Investment With Allowance	940		940		382
Total Recorded Investment	2,980		2,980		3,662
Related Allowance	528		528		$ 112
Impaired Financing Receivable, Average Recorded Investment and Cash Basis Method Interest Income
Average Recorded Investment	2,068	753	3,321	846
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Income Recognized	$ 0	$ 0	$ 2	$ 0

Schedule of Loans Renegotiated

Schedule of Loans Renegotiated in Troubled Debt Restructurings (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2017USD ($)notes	Jun. 30, 2016USD ($)	Jun. 30, 2017USD ($)notes	Jun. 30, 2016USD ($)	Dec. 31, 2016USD ($)
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Loans Renegotiated in Troubled Debt Restructurings	$ 52,351,000		$ 52,351,000		$ 49,652,000
Loans Renegotiated in Troubled Debt Restructurings, Non-Accrual Loans	37,395,000		37,395,000		27,309,000
Loans Renegotiated in Troubled Debt Restructurings, Accrual Loans	$ 14,956,000		$ 14,956,000		$ 22,343,000
Number of Notes | notes	3		20
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 707,000		$ 10,697,000
Financing Receivables, Impaired, Troubled Debt Restructuring, Write-down	$ 0	$ 0	$ 0	$ 0
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	4		4
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 6,338,000		$ 6,338,000
Loans and Leases Receivable, Impaired, Commitment to Lend	0		0
Interest only period
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Pre-Modification Recorded Investment	16,000		1,986,000
Extension of terms or maturity
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Pre-Modification Recorded Investment	226,000		2,356,000
Interest Rate Adjustment Concession [Member]
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Pre-Modification Recorded Investment	0		0
Other Concession [Member]
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 465,000		$ 6,355,000
Commercial real estate
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Number of Notes | notes	1		5
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 226,000		$ 2,772,000
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | notes	3		3
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 2,763,000		$ 2,763,000
Commercial real estate | Interest only period
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Pre-Modification Recorded Investment	0		1,475,000
Commercial real estate | Extension of terms or maturity
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Pre-Modification Recorded Investment	226,000		388,000
Commercial real estate | Interest Rate Adjustment Concession [Member]
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Pre-Modification Recorded Investment	0		0
Commercial real estate | Other Concession [Member]
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 0		$ 909,000
Commercial construction real estate
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | notes	1		1
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 3,575,000		$ 3,575,000
Commercial
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Number of Notes | notes	2		15
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 481,000		$ 7,925,000
Commercial | Interest only period
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Pre-Modification Recorded Investment	16,000		511,000
Commercial | Extension of terms or maturity
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Pre-Modification Recorded Investment	0		1,968,000
Commercial | Interest Rate Adjustment Concession [Member]
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Pre-Modification Recorded Investment	0		0
Commercial | Other Concession [Member]
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 465,000		$ 5,446,000

Schedule of Recorded Investme51

Schedule of Recorded Investment in Criticized Loans by Class and Credit Quality Indicator (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	$ 7,525,590	$ 5,416,750
Commercial real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	2,816,526	1,834,445
Land acquisition & development construction real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	339,884	208,512
Residential construction real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	219,756	147,896
Commercial construction real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	121,605	125,589
Total construction loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	681,245	481,997
Residential real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	1,466,014	1,027,393
Agricultural real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	163,175	170,248
Total real estate loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	5,126,960	3,514,083
Indirect consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	779,026	752,409
Other consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	175,737	148,087
Credit card consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	75,631	69,770
Total consumer loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	1,030,394	970,266
Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	1,210,869	797,942
Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	149,129	132,858
Other Assets Especially Mentioned
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	163,076	163,581
Other Assets Especially Mentioned | Commercial real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	89,093	85,292
Other Assets Especially Mentioned | Land acquisition & development construction real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	17,516	13,414
Other Assets Especially Mentioned | Residential construction real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	2,609	412
Other Assets Especially Mentioned | Commercial construction real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	1,520	1,555
Other Assets Especially Mentioned | Total construction loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	21,645	15,381
Other Assets Especially Mentioned | Residential real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	4,831	5,038
Other Assets Especially Mentioned | Agricultural real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	1,319	3,831
Other Assets Especially Mentioned | Total real estate loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	116,888	109,542
Other Assets Especially Mentioned | Indirect consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	707	778
Other Assets Especially Mentioned | Other consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	609	681
Other Assets Especially Mentioned | Credit card consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	0
Other Assets Especially Mentioned | Total consumer loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	1,316	1,459
Other Assets Especially Mentioned | Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	39,346	46,402
Other Assets Especially Mentioned | Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	5,526	6,178
Substandard
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	222,411	172,325
Substandard | Commercial real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	105,050	85,293
Substandard | Land acquisition & development construction real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	6,785	6,214
Substandard | Residential construction real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	2,503	1,621
Substandard | Commercial construction real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	3,844	6,344
Substandard | Total construction loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	13,132	14,179
Substandard | Residential real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	11,754	12,472
Substandard | Agricultural real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	16,016	17,813
Substandard | Total real estate loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	145,952	129,757
Substandard | Indirect consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	2,096	1,527
Substandard | Other consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	835	1,036
Substandard | Credit card consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	185
Substandard | Total consumer loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	3,116	2,563
Substandard | Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	57,731	29,281
Substandard | Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	15,612	10,724
Doubtful
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	44,189	36,336
Doubtful | Commercial real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	14,265	10,842
Doubtful | Land acquisition & development construction real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	1,383	1,401
Doubtful | Residential construction real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	548	656
Doubtful | Commercial construction real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	4,221	664
Doubtful | Total construction loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	6,152	2,721
Doubtful | Residential real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	874	764
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	21,291	14,327
Doubtful | Indirect consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	126	101
Doubtful | Other consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	135	264
Doubtful | Credit card consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	0
Doubtful | Total consumer loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	261	365
Doubtful | Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	21,310	21,240
Doubtful | Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	1,327	404
Total Criticized Loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	429,676	372,242
Total Criticized Loans | Commercial real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	208,408	181,427
Total Criticized Loans | Land acquisition & development construction real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	25,684	21,029
Total Criticized Loans | Residential construction real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	5,660	2,689
Total Criticized Loans | Commercial construction real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	9,585	8,563
Total Criticized Loans | Total construction loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	40,929	32,281
Total Criticized Loans | Residential real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	17,459	18,274
Total Criticized Loans | Agricultural real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	17,335	21,644
Total Criticized Loans | Total real estate loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	284,131	253,626
Total Criticized Loans | Indirect consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	2,929	2,406
Total Criticized Loans | Other consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	1,579	1,981
Total Criticized Loans | Credit card consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	185
Total Criticized Loans | Total consumer loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	4,693	4,387
Total Criticized Loans | Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	118,387	96,923
Total Criticized Loans | Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	$ 22,465	$ 17,306

Schedule of Allowance for Loan

Schedule of Allowance for Loan Losses by Portfolio Segment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Dec. 31, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]
Certain Loans and Debt Securities Acquired in Transfer, Allowance for Credit Losses Due to Subsequent Impairment					$ 701	$ 427
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	$ 76,231	$ 79,924	$ 76,214	$ 76,817
Provision charged to operating expense	2,355	2,550	4,085	6,550
Less loans charged-off	(4,489)	(3,441)	(8,162)	(7,743)
Add back recoveries of loans previously charged-off	1,604	1,307	3,564	4,716
Ending balance	75,701	80,340	75,701	80,340
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Loans individually evaluated for impairment					16,316	13,954
Loans collectively evaluated for impairment					59,385	62,260
Ending balance	76,231	79,924	76,214	76,817	75,701	76,214
Total loans:
Individually evaluated for impairment					97,231	104,691
Individually evaluated for impairment					7,428,359	5,312,059
Total loans					7,525,590	5,416,750
Real Estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	33,092	36,652	28,625	52,296
Provision charged to operating expense	1,078	(4,059)	5,465	(20,140)
Less loans charged-off	(980)	(523)	(1,243)	(2,445)
Add back recoveries of loans previously charged-off	308	211	651	2,570
Ending balance	33,498	32,281	33,498	32,281
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Loans individually evaluated for impairment					8,898	4,588
Loans collectively evaluated for impairment					24,600	24,037
Ending balance	33,092	36,652	28,625	52,296	33,498	28,625
Total loans:
Individually evaluated for impairment					62,323	68,632
Individually evaluated for impairment					5,064,637	3,445,451
Total loans					5,126,960	3,514,083
Total consumer loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	8,368	5,256	7,711	5,144
Provision charged to operating expense	489	2,123	2,537	3,352
Less loans charged-off	(2,412)	(1,712)	(5,008)	(3,604)
Add back recoveries of loans previously charged-off	1,109	648	2,314	1,423
Ending balance	7,554	6,315	7,554	6,315
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Loans individually evaluated for impairment					8	0
Loans collectively evaluated for impairment					7,546	7,711
Ending balance	8,368	5,256	7,711	5,144	7,554	7,711
Total loans:
Individually evaluated for impairment					25	0
Individually evaluated for impairment					1,030,369	970,266
Total loans					1,030,394	970,266
Commercial
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	33,562	36,252	38,092	18,775
Provision charged to operating expense	453	4,313	(3,675)	22,003
Less loans charged-off	(1,049)	(1,018)	(1,841)	(1,506)
Add back recoveries of loans previously charged-off	158	448	548	723
Ending balance	33,124	39,995	33,124	39,995
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Loans individually evaluated for impairment					6,882	9,254
Loans collectively evaluated for impairment					26,242	28,838
Ending balance	33,562	36,252	38,092	18,775	33,124	38,092
Total loans:
Individually evaluated for impairment					31,903	32,397
Individually evaluated for impairment					1,178,966	765,545
Total loans					1,210,869	797,942
Agriculture
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	1,209	1,764	1,786	602
Provision charged to operating expense	335	173	(242)	1,335
Less loans charged-off	(48)	(188)	(70)	(188)
Add back recoveries of loans previously charged-off	29	0	51	0
Ending balance	1,525	1,749	1,525	1,749
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Loans individually evaluated for impairment					528	112
Loans collectively evaluated for impairment					997	1,674
Ending balance	1,209	1,764	1,786	602	1,525	1,786
Total loans:
Individually evaluated for impairment					2,980	3,662
Individually evaluated for impairment					146,149	129,196
Total loans					149,129	132,858
Other
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	0	0	0	0
Provision charged to operating expense	0	0	0	0
Less loans charged-off	0	0	0	0
Add back recoveries of loans previously charged-off	0	0	0	0
Ending balance	0	0	0	0
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Loans individually evaluated for impairment					0	0
Loans collectively evaluated for impairment					0	0
Ending balance	$ 0	$ 0	$ 0	$ 0	0	0
Total loans:
Individually evaluated for impairment					0	0
Individually evaluated for impairment					8,238	1,601
Total loans					$ 8,238	$ 1,601

OREO (Details)

OREO (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Real Estate Acquired Through Foreclosure, Acquired Through Acquisition	$ 1,055	$ 0	$ 1,055	$ 0
Mortgage Loans in Process of Foreclosure, Amount	0		0
Real Estate Acquired Through Foreclosure [Roll Forward]
Beginning balance	9,428	9,257	10,019	6,254
Additions	1,395	792	1,763	4,019
Valuation adjustments	(9)	(586)	(56)	(603)
Dispositions	(583)	(1,555)	(1,495)	(1,762)
Ending balance	11,286	$ 7,908	11,286	$ 7,908
Residential real estate
Real Estate Acquired Through Foreclosure [Roll Forward]
Beginning balance			2,282
Ending balance	$ 2,686		$ 2,686

Derivatives and Hedging (Detail

Derivatives and Hedging (Details) - USD ($)	Sep. 22, 2015	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset		$ 10,599,000		$ 10,599,000		$ 2,749,000
Derivative Asset, Fair Value, Gross Liability		0		0		0
Derivative Asset, Fair Value, Amount Not Offset Against Collateral		10,599,000		10,599,000		2,749,000
Derivative Asset Netting Adjustment Per Applicable Master Netting Agreements		1,547,000		1,547,000		479,000
Impaired Financing Receivable, Interest Income, Accrual Method		0		0		0
Derivative Asset, Fair Value, Amount Offset Against Collateral		9,052,000		9,052,000		2,270,000
Total Assets, Fair Value, Gross Asset		10,599,000		10,599,000		2,749,000
Total Assets, Fair Value, Gross Liability		0		0		0
Total Assets, Fair value, Amount Not Offset Against Collateral		10,599,000		10,599,000		2,749,000
Total Asset Netting Adjustment Per Applicable Master Netting Arrangements		1,547,000		1,547,000		479,000
Total Collateral, Obligation to Return Cash		0		0		0
Total Asset, Fair Value, Amount Offset Against Collateral		9,052,000		9,052,000		2,270,000
Derivative, Inception Date	Sep. 22, 2015
Derivative, Fixed Interest Rate	1.94%
Derivative Asset, Notional Amount		468,071,000		468,071,000		253,851,000
Interest Rate Derivative Assets, at Fair Value		10,599,000		10,599,000		2,749,000
Derivative Liability, Notional Amount	$ 100,000,000	420,809,000		420,809,000		153,593,000
Interest Rate Derivative Liabilities, at Fair Value		9,797,000		9,797,000		1,314,000
Derivative Liability, Fair Value, Gross Liability		9,797,000		9,797,000		1,314,000
Derivative Liability, Fair Value, Gross Asset		0		0		0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral		9,797,000		9,797,000		1,314,000
Derivative Liability Netting Adjustment Per Applicable Master Netting Agreements		1,547,000		1,547,000		479,000
Derivative, Collateral, Right to Reclaim Cash		8,250,000		8,250,000		0
Derivative Liability, Fair Value, Amount Offset Against Collateral		0		0		835,000
Securities Sold under Agreements to Repurchase, Fair Value of Collateral		579,772,000		579,772,000		537,556,000
Securities Sold under Agreements to Repurchase, Gross		0		0		0
Securities Sold under Agreements to Repurchase, Not Offset, Policy Election Deduction		579,772,000		579,772,000		537,556,000
Securities Sold Under Agreement to Repurchase, Amount Not Offset Against Collateral		0		0		0
Securities Purchased under Agreements to Resell, Collateral, Obligation to Return Securities		579,772,000		579,772,000		537,556,000
Securities Sold under Agreements to Repurchase, Amount Offset Against Collateral		0		0		0
Total Liabilities, Fair Value, Gross Amount		589,569,000		589,569,000		538,870,000
Total Liabilities, Fair Value, Gross Liability		0		0		0
Total Liabilities, Fair value, Amount Not Offset Against Collateral		589,569,000		589,569,000		538,870,000
Total Liabilities Netting Adjustment Per Applicable Master Netting Arrangements		1,547,000		1,547,000		479,000
Total Collateral, Obligation to Return Cash or Securities		588,022,000		588,022,000		537,556,000
Total Liabilities, Fair Value, Amount Offset Against Collateral		0		0		835,000
Interest Rate Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net				372
Interest Rate Swap
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset		9,001,000		9,001,000		1,332,000
Derivative Asset, Fair Value, Gross Liability		0		0		0
Derivative Asset, Fair Value, Amount Not Offset Against Collateral		9,001,000		9,001,000		1,332,000
Derivative Asset Netting Adjustment Per Applicable Master Netting Agreements		1,547,000		1,547,000		479,000
Impaired Financing Receivable, Interest Income, Accrual Method		0		0		0
Derivative Asset, Fair Value, Amount Offset Against Collateral		7,454,000		7,454,000		853,000
Derivative Liability, Notional Amount		100,000,000		100,000,000
Mortgage Related Derivatives [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset		1,598,000		1,598,000		1,417,000
Derivative Asset, Fair Value, Gross Liability		0		0		0
Derivative Asset, Fair Value, Amount Not Offset Against Collateral		1,598,000		1,598,000		1,417,000
Derivative Asset Netting Adjustment Per Applicable Master Netting Agreements		0		0		0
Impaired Financing Receivable, Interest Income, Accrual Method		0		0		0
Derivative Asset, Fair Value, Amount Offset Against Collateral		1,598,000		1,598,000		1,417,000
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative Instruments, Loss Recognized in Other Comprehensive Income (Loss), Effective Portion		(486,000)	$ (804,000)	(437,000)	$ (3,002,000)
Designated as Hedging Instrument [Member] | Interest Rate Swap
Derivative [Line Items]
Derivative Liability, Notional Amount		100,000,000		100,000,000		100,000,000
Interest Rate Derivative Liabilities, at Fair Value		470,000		470,000		33,000
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Loss on Derivative		70,000	(50,000)	31,000	(79,000)
Fee Income on Derivatives		321,000	245,000	279,000	245,000
Gain (Loss) on Fair Value Hedges Recognized in Earnings		290,000	$ 523,000	181,000	$ 1,218,000
Not Designated as Hedging Instrument [Member] | Interest Rate Swap
Derivative [Line Items]
Derivative Asset, Notional Amount		320,809,000		320,809,000		53,593,000
Interest Rate Derivative Assets, at Fair Value		9,001,000		9,001,000		1,332,000
Derivative Liability, Notional Amount		320,809,000		320,809,000		53,593,000
Interest Rate Derivative Liabilities, at Fair Value		9,327,000		9,327,000		1,281,000
Not Designated as Hedging Instrument [Member] | Interest Rate Lock Commitments [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount		64,673,000		64,673,000		73,422,000
Interest Rate Derivative Assets, at Fair Value		1,301,000		1,301,000		1,131,000
Not Designated as Hedging Instrument [Member] | Forward Contracts [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount		82,589,000		82,589,000		126,836,000
Interest Rate Derivative Assets, at Fair Value		$ 297,000		$ 297,000		$ 286,000

Capital Stock (Details)

Capital Stock (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	May 30, 2017	Dec. 31, 2016
Class of Stock [Line Items]
Business Acquisition, Equity Interest Issued or Issuable, Value Assigned	$ 385,969		$ 385,969
Share-based Compensation Arrangement by Share-based Payment Award, Aggregate Value of Shares Issued	522
Payments for Repurchase of Common Stock	$ 891	$ 26,042
Class A Common Stock
Class of Stock [Line Items]
Common Stock, Shares, Outstanding	33,260,710			21,613,885
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares	11,252,750
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period	14,926
Stock Repurchased and Retired During Period, Shares		975,877
Payments for Repurchase of Common Stock		$ 25,525
Stock Repurchase Program, Remaining Authorized Repurchase Amount	24,123
Class B Common Stock
Class of Stock [Line Items]
Common Stock, Shares, Outstanding	23,184,557			23,312,291

Computation of Basic and Dilute

Computation of Basic and Diluted Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Net Income (Loss) Available to Common Stockholders, Basic
Net income	$ 21,868	$ 25,554	$ 44,994	$ 45,678
Weighted Average Number of Shares Outstanding, Basic and Diluted
Weighted average common shares outstanding for basic earnings per share computation	47,612,971	44,268,985	46,170,500	44,494,102
Dilutive effect of stock-based compensation	461,480	376,190	510,875	385,513
Weighted average common shares outstanding for diluted earnings per common share computation	48,074,451	44,645,175	46,681,375	44,879,615
Earnings Per Share, Basic and Diluted
Basic earnings per common share	$ 0.46	$ 0.58	$ 0.97	$ 1.03
Diluted earnings per common share	$ 0.45	$ 0.57	$ 0.96	$ 1.02
Performance Shares [Member]
Earnings Per Share, Basic and Diluted [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount			182,835	221,322
Unvested Restricted Stock
Earnings Per Share, Basic and Diluted [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	96,262	96,726	92,626	96,726

Schedule of Actual Capital Amou

Schedule of Actual Capital Amounts and Ratios and Selected Minimum Regulatory Thresholds (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Total risk-based capital:
Actual Amount	$ 1,086,842	$ 974,488
Actual Ratio	12.56%	15.13%
Well Capitalized Amount	$ 865,061	$ 643,876
Well Capitalized Ratio	10.00%	10.00%
Tier 1 risk-based capital:
Actual Amount	$ 1,011,141	$ 894,273
Actual Ratio	11.69%	13.89%
Well Capitalized Amount	$ 692,049	$ 515,101
Well Capitalized Ratio	8.00%	8.00%
Common equity tier one risk-based capital:
Actual Amount	$ 931,675	$ 814,273
Actual Ratio	10.77%	12.65%
Leverage capital ratio:
Actual Amount	$ 1,011,141	$ 894,273
Actual Ratio	10.65%	10.11%
Adequately Capitalized Amount	$ 379,616	$ 353,838
Adequately Capitalized Ratio	4.00%	4.00%
Well Capitalized Amount	$ 474,519	$ 442,297
Well Capitalized Ratio	5.00%	5.00%
Capital Required for Capital Adequacy under Basel III Phase-in Schedule	$ 800,182	$ 555,665
Capital Required for Capital Adequacy under Basel III Phase-in Schedule to Risk Weighted Assets	9.25%	8.63%
Capital Required for Capital Adequacy under Basel III Fully Phased-in	$ 908,314	$ 676,070
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	$ 627,169	$ 426,890
Tier One Capital Required for Capital Adequacy under Basel III Phase-in Schedule to Risk Weighted Assets	7.25%	6.63%
Tier One Capital Required for Capital Adequacy under Basel III Fully Phased-in	$ 735,302	$ 547,295
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	$ 497,410	$ 330,308
Common Equity Tier One Capital Required for Capital Adequacy under Basel III Phase-in Schedule to Risk Weighted Assets	5.75%	5.13%
Tier One Common Equity Capital Required for Capital Adequacy under Basel III Fully Phased-in	$ 605,543	$ 450,713
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	$ 562,290	$ 418,519
Common Equity Tier One Capital to be Well Capitalized to Risk Weighted Assets	6.50%	6.50%
FIB
Total risk-based capital:
Actual Amount	$ 824,454	$ 841,967
Actual Ratio	13.00%	13.13%
Well Capitalized Amount	$ 634,208	$ 641,320
Well Capitalized Ratio	10.00%	10.00%
Tier 1 risk-based capital:
Actual Amount	$ 748,753	$ 765,753
Actual Ratio	11.81%	11.94%
Well Capitalized Amount	$ 507,366	$ 513,056
Well Capitalized Ratio	8.00%	8.00%
Common equity tier one risk-based capital:
Actual Amount	$ 748,753	$ 765,753
Actual Ratio	11.81%	11.94%
Leverage capital ratio:
Actual Amount	$ 748,753	$ 765,753
Actual Ratio	8.67%	8.69%
Adequately Capitalized Amount	$ 345,442	$ 352,283
Adequately Capitalized Ratio	4.00%	4.00%
Well Capitalized Amount	$ 431,803	$ 440,353
Well Capitalized Ratio	5.00%	5.00%
Capital Required for Capital Adequacy under Basel III Phase-in Schedule	$ 586,642	$ 553,459
Capital Required for Capital Adequacy under Basel III Phase-in Schedule to Risk Weighted Assets	9.25%	8.63%
Capital Required for Capital Adequacy under Basel III Fully Phased-in	$ 665,918	$ 673,386
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	$ 459,801	$ 425,195
Tier One Capital Required for Capital Adequacy under Basel III Phase-in Schedule to Risk Weighted Assets	7.25%	6.63%
Tier One Capital Required for Capital Adequacy under Basel III Fully Phased-in	$ 539,077	$ 545,122
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	$ 364,669	$ 328,997
Common Equity Tier One Capital Required for Capital Adequacy under Basel III Phase-in Schedule to Risk Weighted Assets	5.75%	5.13%
Tier One Common Equity Capital Required for Capital Adequacy under Basel III Fully Phased-in	$ 443,945	$ 448,924
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	$ 412,235	$ 416,858
Common Equity Tier One Capital to be Well Capitalized to Risk Weighted Assets	6.50%	6.50%
Bank of the Cascades [Member]
Total risk-based capital:
Actual Amount	$ 240,391
Actual Ratio	10.53%
Well Capitalized Amount	$ 228,265
Well Capitalized Ratio	10.00%
Tier 1 risk-based capital:
Actual Amount	$ 240,391
Actual Ratio	10.53%
Well Capitalized Amount	$ 182,612
Well Capitalized Ratio	8.00%
Common equity tier one risk-based capital:
Actual Amount	$ 240,391
Actual Ratio	10.53%
Leverage capital ratio:
Actual Amount	$ 240,391
Actual Ratio	8.12%
Adequately Capitalized Amount	$ 118,476
Adequately Capitalized Ratio	4.00%
Well Capitalized Amount	$ 148,095
Well Capitalized Ratio	5.00%
Capital Required for Capital Adequacy under Basel III Phase-in Schedule	$ 211,145
Capital Required for Capital Adequacy under Basel III Phase-in Schedule to Risk Weighted Assets	9.25%
Capital Required for Capital Adequacy under Basel III Fully Phased-in	$ 239,678
Capital Required for Capital Adequacy under Basel III Fully Phased-in to Risk Weighted Assets	10.50%
Tier One Risk Based Capital under Basel III Phase-in Schedule	$ 165,492
Tier One Capital Required for Capital Adequacy under Basel III Phase-in Schedule to Risk Weighted Assets	7.25%
Tier One Capital Required for Capital Adequacy under Basel III Fully Phased-in	$ 194,025
Tier One Capital Required for Capital Adequacy under Basel III Fully Phased-in to Risk Weighted Assets	8.50%
Common Equity Tier One Capital Required for Capital Adequacy under Basel III Phase-in Schedule	$ 131,252
Common Equity Tier One Capital Required for Capital Adequacy under Basel III Phase-in Schedule to Risk Weighted Assets	5.75%
Tier One Common Equity Capital Required for Capital Adequacy under Basel III Fully Phased-in	$ 159,786
Tier One Common Equity Capital Required for Capital Adequacy under Basel III Fully Phased-in to Risk Weighted Assets	7.00%
Common Equity Tier One Capital to be Well Capitalized	$ 148,372
Common Equity Tier One Capital to be Well Capitalized to Risk Weighted Assets	6.50%

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Dec. 31, 2016	Sep. 22, 2015
Loss Contingencies [Line Items]
Derivative Liability, Notional Amount	$ 420,809	$ 153,593	$ 100,000
Commitments to Complete Contracts in Process	1,374
Interest Rate Swap
Loss Contingencies [Line Items]
Derivative Liability, Notional Amount	$ 100,000
Mortgage Loans Held for Sale
Loss Contingencies [Line Items]
Guarantor Obligations, Recourse Provisions	999

Financial Instruments with Of59

Financial Instruments with Off-Balance Sheet Risk (Details) $ in Thousands	Jun. 30, 2017USD ($)
Entity Information [Line Items]
Credit Extension Commitments	$ 2,250,387
Credit Extension Commitments, Beyond One Year	874,134
Standby Letters of Credit
Entity Information [Line Items]
Credit Extension Commitments	54,241
Unused Credit Card Lines
Entity Information [Line Items]
Credit Extension Commitments	$ 673,280

Schedule of Comprehensive Incom

Schedule of Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Change in net unrealized Gain during period:
Change in net unrealized gain during period, before tax amount	$ 8,006	$ 10,043	$ 17,365	$ 18,671
Change in net unrealized gain during period, tax expense (benefit)	3,298	3,947	6,985	7,322
Change in net unrealized gain during period, net of tax amount	4,708	6,096	10,380	11,349
Reclassification adjustment for gains included in net income:
Reclassification adjustment for gains included in net income, before tax amount	(5)	(108)	(7)	(87)
Reclassification adjustment for gains included in net income, tax expense (benefit)	(2)	(42)	(3)	(34)
Reclassification adjustment for gains included in net income, net of tax amount	(3)	(66)	(4)	(53)
Change in unamortized loss on available-for-sale securities transferred into held-to-maturity	464	452	929	904
Other Comprehensive Income (Loss), Transfers from Held-to-maturity to Available-for-Sale Securities, Tax	191	170	374	340
Change in unamortized loss on available-for-sale securities transferred into held-to-maturity	273	282	555	564
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax	(486)	(804)	(437)	(3,002)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	(201)	(305)	(176)	(1,141)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(285)	(499)	(261)	(1,861)
Change in net actuarial loss:
Change in net actuarial loss, before tax amount	(176)	13	(914)	28
Change in net actuarial loss, tax expense (benefit)	(72)	5	(368)	11
Change in net actuarial loss, net of tax amount	(104)	8	(546)	17
Other comprehensive income (loss):
Other comprehensive income (loss), before tax	7,803	9,596	16,936	16,514
Total other comprehensive income, tax expense (benefit)	3,214	3,775	6,812	6,498
Total other comprehensive income, net of tax amount	$ 4,589	$ 5,821	$ 10,124	$ 10,016

Schedule of Accumulated Other C

Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Net accumulated other comprehensive income:
Net unrealized gain on investment securities available-for-sale	$ 947	$ (10,143)
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	(434)	(23)
Net actuarial loss on defined benefit post-retirement benefit plans	1,483	2,038
Net accumulated other comprehensive income	$ 1,996	$ (8,128)

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		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Real Estate Acquired Through Foreclosure, Valuation Adjustments	$ 9	$ 586	$ 56	$ 603
Related Allowance	16,316		16,316		$ 13,954
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		0		0
Deferred compensation asset at fair value amount	0		0		0
Deferred compensation plan liabilities at fair value amount	0		0		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		0
Other real estate owned	0		0		0
Long-lived assets to be disposed of by sale	0		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	30,383		30,383		61,794
Deferred compensation asset at fair value amount	11,598		11,598		10,627
Deferred compensation plan liabilities at fair value amount	11,598		11,598		10,627
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		0
Other real estate owned	0		0		0
Long-lived assets to be disposed of by sale	0		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		0		0
Deferred compensation asset at fair value amount	0		0		0
Deferred compensation plan liabilities at fair value amount	0		0		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					39,344
Other real estate owned	1,422		1,422		2,110
Real Estate Acquired Through Foreclosure, Valuation Adjustments			56	603
Impairment of real estate, received updated appraisal			25	550
Impairment of Real Estate, Change in Management Estimates			31	$ 53
Long-lived assets to be disposed of by sale	356		356		1,335
Related Allowance	15,614		15,614		13,954
Impaired Financing Receivable, Related Allowance, Partial Loan Charge-Offs	10,533		10,533		11,941
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		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	3,607		3,607		3,612
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		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		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	675,318		675,318		391,297
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		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		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	1,222,937		1,222,937		1,213,701
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		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		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	108,485		108,485		116
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		0
Corporate Debt 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
Corporate Debt 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	66,884		66,884
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		0		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	2,963		2,963		2,972
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		0		0
Estimated Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	2,080,194		2,080,194		1,611,698
Loans Receivable, Fair Value Disclosure	7,325,012		7,325,012		5,248,127
Derivative Asset	10,599		10,599		2,749
Derivative Liability	9,797		9,797		1,314
Mortgages Held-for-sale, Fair Value Disclosure	30,383		30,383		61,794
Deferred compensation asset at fair value amount	11,598		11,598		10,627
Deferred compensation plan liabilities at fair value amount	11,598		11,598		10,627
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	30,383		30,383		61,794
Deferred compensation asset at fair value amount	11,598		11,598		10,627
Deferred compensation plan liabilities at fair value amount	11,598		11,598		10,627
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	34,975		34,975		39,344
Other real estate owned	1,422		1,422		2,110
Long-lived assets to be disposed of by sale	356		356		1,335
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		0
Loans Receivable, Fair Value Disclosure	0		0		0
Derivative Asset	0		0		0
Derivative Liability	0		0		0
Mortgages Held-for-sale, Fair Value Disclosure	0		0		0
Deferred compensation asset at fair value amount	0		0		0
Deferred compensation plan liabilities at fair value amount	0		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	2,080,194		2,080,194		1,611,698
Loans Receivable, Fair Value Disclosure	7,290,037		7,290,037		5,208,783
Derivative Asset	10,599		10,599		2,749
Derivative Liability	9,797		9,797		1,314
Mortgages Held-for-sale, Fair Value Disclosure	30,383		30,383		61,794
Deferred compensation asset at fair value amount	11,598		11,598		10,627
Deferred compensation plan liabilities at fair value amount	11,598		11,598		10,627
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		0
Loans Receivable, Fair Value Disclosure	34,975		34,975		39,344
Derivative Asset	0		0		0
Derivative Liability	0		0		0
Mortgages Held-for-sale, Fair Value Disclosure	0		0
Deferred compensation asset at fair value amount	0		0		0
Deferred compensation plan liabilities at fair value amount	0		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	34,975		34,975		39,344
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	3,607		3,607		3,612
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	675,318		675,318		391,297
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	1,222,937		1,222,937		1,213,701
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	108,485		108,485		116
Estimated Fair Value | Corporate Debt 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	66,884		66,884
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	2,963		2,963		2,972
Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	2,080,194		2,080,194		1,611,698
Loans Receivable, Fair Value Disclosure	7,449,889		7,449,889		5,340,536
Derivative Asset	10,599		10,599		2,749
Derivative Liability	9,797		9,797		1,314
Mortgages Held-for-sale, Fair Value Disclosure	30,383		30,383		61,794
Deferred compensation asset at fair value amount	11,598		11,598		10,627
Deferred compensation plan liabilities at fair value amount	11,598		11,598		10,627
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	61,122		61,122		65,238
Long-lived assets to be disposed of by sale	565		565		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	209		209		1,028
Interest Rate Swap | 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		0
Derivative Liability	0		0		0
Interest Rate Swap | 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	9,001		9,001		1,332
Derivative Liability	9,797		9,797		1,314
Interest Rate Swap | 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		0
Derivative Liability	0		0		0
Interest Rate Swap | 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	9,001		9,001		1,332
Derivative Liability	9,797		9,797		1,314
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		0		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	1,301		1,301		1,131
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		0		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	1,301		1,301		1,131
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 Asset	0		0		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 Asset	297		297		286
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 Asset	0		0		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 Asset	$ 297		$ 297		$ 286

Fair Value Measurements Fair Va

Fair Value Measurements Fair Value Inputs, Quantitative Information (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
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	(66.00%)
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	(31.00%)
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	(8.00%)
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	(18.00%)
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%)
Carrying Amount
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loans Receivable, Fair Value Disclosure	$ 7,449,889	$ 5,340,536
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	209	1,028
Estimated Fair Value
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loans Receivable, Fair Value Disclosure	7,325,012	5,248,127
Estimated Fair Value | Fair Value Measured on a Non-recurring Basis
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired loans	34,975	39,344
Long-lived assets to be disposed of by sale	356	1,335
Other real estate owned	1,422	2,110
Significant Unobservable Inputs (Level 3) | Fair Value Measured on a Non-recurring Basis
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired loans		39,344
Long-lived assets to be disposed of by sale	356	1,335
Other real estate owned	1,422	2,110
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	61,122	65,238
Long-lived assets to be disposed of by sale	565	2,363
Significant Unobservable Inputs (Level 3) | Estimated Fair Value
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loans Receivable, Fair Value Disclosure	34,975	39,344
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	$ 34,975	$ 39,344

Schedule of Estimated Fair Valu

Schedule of Estimated Fair Values of Financial Instruments by Level of Valuation Inputs (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Financial assets:
Investment securities held-to-maturity	$ 535,145	$ 513,273
Carrying Amount
Financial assets:
Cash and cash equivalents	919,775	782,023
Investment securities available-for-sale	2,080,194	1,611,698
Investment securities held-to-maturity	529,442	512,770
Accrued interest receivable	35,830	29,852
Mortgage servicing rights	23,715	18,457
Mortgages Held-for-sale, Fair Value Disclosure	30,383	61,794
Loans Receivable, Fair Value Disclosure	7,449,889	5,340,536
Derivative Asset	10,599	2,749
Deferred compensation asset at fair value amount	11,598	10,627
Total financial assets	11,091,425	8,370,506
Financial liabilities:
Total deposits, excluding time deposits	8,817,211	6,324,512
Time deposits	1,202,789	1,051,598
Securities sold under repurchase agreements	579,772	537,556
Other borrowed funds	15,019	6
Accrued interest payable	8,917	5,421
Long-term debt	28,017	27,970
Subordinated debentures held by subsidiary trusts	82,477	82,477
Derivative Liability	9,797	1,314
Deferred compensation plan liabilities at fair value amount	11,598	10,627
Total financial liabilities	10,755,597	8,041,481
Estimated Fair Value
Financial assets:
Cash and cash equivalents	919,775	782,023
Investment securities available-for-sale	2,080,194	1,611,698
Investment securities held-to-maturity	535,145	513,273
Accrued interest receivable	35,830	29,852
Mortgage servicing rights	34,580	35,656
Mortgages Held-for-sale, Fair Value Disclosure	30,383	61,794
Loans Receivable, Fair Value Disclosure	7,325,012	5,248,127
Derivative Asset	10,599	2,749
Deferred compensation asset at fair value amount	11,598	10,627
Total financial assets	10,983,116	8,295,799
Financial liabilities:
Total deposits, excluding time deposits	8,817,211	6,324,512
Time deposits	1,195,454	1,044,670
Securities sold under repurchase agreements	579,772	537,556
Other borrowed funds	15,019	6
Accrued interest payable	8,917	5,421
Long-term debt	28,240	27,477
Subordinated debentures held by subsidiary trusts	91,519	73,554
Derivative Liability	9,797	1,314
Deferred compensation plan liabilities at fair value amount	11,598	10,627
Total financial liabilities	10,757,527	8,025,137
Quoted Prices in Active Markets for Identical Assets (Level 1) | Estimated Fair Value
Financial assets:
Cash and cash equivalents	919,775	782,023
Investment securities available-for-sale	0	0
Investment securities held-to-maturity	0	0
Accrued interest receivable	0	0
Mortgage servicing rights	0	0
Mortgages Held-for-sale, Fair Value Disclosure	0	0
Loans Receivable, Fair Value Disclosure	0	0
Derivative Asset	0	0
Deferred compensation asset at fair value amount	0	0
Total financial assets	919,775	782,023
Financial liabilities:
Total deposits, excluding time deposits	8,817,211	6,324,512
Time deposits	0	0
Securities sold under repurchase agreements	0	0
Other borrowed funds	0	0
Accrued interest payable	0	0
Long-term debt	0	0
Subordinated debentures held by subsidiary trusts	0	0
Derivative Liability	0	0
Deferred compensation plan liabilities at fair value amount	0	0
Total financial liabilities	8,817,211	6,324,512
Significant Other Observable Inputs (Level 2) | Estimated Fair Value
Financial assets:
Cash and cash equivalents	0	0
Investment securities available-for-sale	2,080,194	1,611,698
Investment securities held-to-maturity	535,145	513,273
Accrued interest receivable	35,830	29,852
Mortgage servicing rights	34,580	35,656
Mortgages Held-for-sale, Fair Value Disclosure	30,383	61,794
Loans Receivable, Fair Value Disclosure	7,290,037	5,208,783
Derivative Asset	10,599	2,749
Deferred compensation asset at fair value amount	11,598	10,627
Total financial assets	10,028,366	7,474,432
Financial liabilities:
Total deposits, excluding time deposits	0	0
Time deposits	1,195,454	1,044,670
Securities sold under repurchase agreements	579,772	537,556
Other borrowed funds	15,019	6
Accrued interest payable	8,917	5,421
Long-term debt	28,240	27,477
Subordinated debentures held by subsidiary trusts	91,519	73,554
Derivative Liability	9,797	1,314
Deferred compensation plan liabilities at fair value amount	11,598	10,627
Total financial liabilities	1,940,316	1,700,625
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
Mortgages Held-for-sale, Fair Value Disclosure	0
Loans Receivable, Fair Value Disclosure	34,975	39,344
Derivative Asset	0	0
Deferred compensation asset at fair value amount	0	0
Total financial assets	34,975	39,344
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
Accrued interest payable	0	0
Long-term debt	0	0
Subordinated debentures held by subsidiary trusts	0	0
Derivative Liability	0	0
Deferred compensation plan liabilities at fair value amount	0	0
Total financial liabilities	$ 0	$ 0

Subsequent Events (Details)

Subsequent Events (Details) - Class A Common Stock - Subsequent Event [Member] - $ / shares	Aug. 11, 2017	Aug. 02, 2017	Jul. 20, 2017
Subsequent Event [Line Items]
Dividends Payable, Date Declared			Jul. 20, 2017
Dividends Payable, Amount Per Share	$ 0.24
Dividends Payable, Date to be Paid	Aug. 11, 2017
Dividends Payable, Date of Record		Aug. 2, 2017