Glacier Bancorp (GBCI) 10-Q 8 Nov 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2013	Oct. 22, 2013
Document and Entity Information [Abstract]	'	'
Entity Registrant Name	'GLACIER BANCORP INC	'
Entity Central Index Key	'0000868671	'
Document Type	'10-Q	'
Document Period End Date	30-Sep-13	'
Amendment Flag	'false	'
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q3	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	74,321,966

Unaudited_Condensed_Consolidat

Unaudited Condensed Consolidated Statements of Financial Condition (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, except Share data, unless otherwise specified
Assets	'	'
Cash on hand and in banks	$130,285	$123,270
Interest bearing cash deposits and federal funds sold	124,399	63,770
Cash and cash equivalents	254,684	187,040
Investment securities, available-for-sale	3,318,953	3,683,005
Loans held for sale	61,505	145,501
Loans receivable	4,001,099	3,397,425
Allowance for loan and lease losses	-130,765	-130,854
Loans receivable, net	3,870,334	3,266,571
Premises and equipment, net	168,633	158,989
Other real estate owned	36,531	45,115
Accrued interest receivable	44,261	37,770
Deferred tax asset	47,957	20,394
Core deposit intangible, net	10,228	6,174
Goodwill	129,706	106,100
Non-marketable equity securities	52,192	48,812
Other assets	52,946	41,969
Total assets	8,047,930	7,747,440
Liabilities	'	'
Non-interest bearing deposits	1,397,401	1,191,933
Interest bearing deposits	4,215,479	4,172,528
Securities sold under agreements to repurchase	314,313	289,508
Federal Home Loan Bank advances	967,382	997,013
Other borrowed funds	8,466	10,032
Subordinated debentures	125,526	125,418
Accrued interest payable	3,568	4,675
Other liabilities	67,988	55,384
Total liabilities	7,100,123	6,846,491
Stockholders' Equity	'	'
Preferred shares, $0.01 par value per share, 1,000,000 shares authorized, none issued or outstanding	0	0
Common stock, $0.01 par value per share, 117,187,500 shares authorized	743	719
Paid-in capital	689,751	641,737
Retained earnings - substantially restricted	247,330	210,531
Accumulated other comprehensive income	9,983	47,962
Total stockholders' equity	947,807	900,949
Total liabilities and stockholders' equity	$8,047,930	$7,747,440
Number of common stock shares issued and outstanding	74,307,951	71,937,222

Unaudited_Condensed_Consolidat1

Unaudited Condensed Consolidated Statements of Financial Condition (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
Statement of Financial Position [Abstract]	'	'
Preferred shares, par value	$0.01	$0.01
Preferred shares, authorized	1,000,000	1,000,000
Preferred shares, issued	0	0
Preferred shares, outstanding	0	0
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	117,187,500	117,187,500

Unaudited_Condensed_Consolidat2

Unaudited Condensed Consolidated Statements of Operations (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Interest Income	'	'	'	'
Residential real estate loans	$7,320	$7,740	$21,606	$23,019
Commercial loans	34,291	30,293	92,788	91,764
Consumer and other loans	8,447	8,826	24,220	26,809
Investment securities	19,473	15,156	51,023	52,499
Total interest income	69,531	62,015	189,637	194,091
Interest Expense	'	'	'	'
Deposits	3,398	4,485	10,584	14,048
Securities sold under agreements to repurchase	209	395	646	997
Federal Home Loan Bank advances	2,730	3,116	8,029	9,715
Federal funds purchased and other borrowed funds	54	53	160	176
Subordinated debentures	795	858	2,410	2,613
Total interest expense	7,186	8,907	21,829	27,549
Net Interest Income	62,345	53,108	167,808	166,542
Provision for loan losses	1,907	2,700	5,085	19,250
Net interest income after provision for loan losses	60,438	50,408	162,723	147,292
Non-Interest Income	'	'	'	'
Service charges and other fees	13,711	11,939	36,115	33,722
Miscellaneous loan fees and charges	1,408	1,080	3,650	3,139
Gain on sale of loans	7,021	8,728	23,582	23,063
Loss on sale of investments	-403	0	-299	0
Other income	2,136	2,227	6,997	6,179
Total non-interest income	23,873	23,974	70,045	66,103
Non-Interest Expense	'	'	'	'
Compensation and employee benefits	27,469	24,046	76,963	71,290
Occupancy and equipment	6,421	6,001	18,152	17,794
Advertising and promotions	1,897	1,820	5,066	4,935
Outsourced data processing	1,232	801	2,870	2,435
Other real estate owned	1,049	6,373	4,901	15,394
Federal Deposit Insurance Corporation premiums	1,331	1,767	3,789	4,779
Core deposit intangibles amortization	693	532	1,684	1,619
Other expense	10,276	8,838	28,858	27,167
Total non-interest expense	50,368	50,178	142,283	145,413
Income Before Income Taxes	33,943	24,204	90,485	67,982
Federal and state income tax expense	8,315	4,760	21,387	13,224
Net Income	$25,628	$19,444	$69,098	$54,758
Basic earnings per share	$0.35	$0.27	$0.95	$0.76
Diluted earnings per share	$0.35	$0.27	$0.95	$0.76
Dividends declared per share	$0.15	$0.13	$0.44	$0.39
Average outstanding shares - basic	73,945,523	71,933,141	72,804,321	71,925,664
Average outstanding shares - diluted	74,021,871	71,973,985	72,869,475	71,925,761

Unaudited_Condensed_Consolidat3

Unaudited Condensed Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Statement of Comprehensive Income [Abstract]	'	'	'	'
Net income	$25,628	$19,444	$69,098	$54,758
Other Comprehensive Income, Net of Tax	'	'	'	'
Unrealized (losses) gains on available-for-sale securities	-21,600	8,733	-77,285	31,965
Reclassification adjustment for losses included in net income	403	0	299	0
Net unrealized (losses) gains on securities	-21,197	8,733	-76,986	31,965
Tax effect	8,246	-3,398	29,948	-12,435
Net of tax amount	-12,951	5,335	-47,038	19,530
Unrealized (losses) gains on derivatives used for cash flow hedges	-735	-2,507	14,827	-8,446
Tax effect	287	975	-5,768	3,285
Net of tax amount	-448	-1,532	9,059	-5,161
Total other comprehensive (loss) income, net of tax	-13,399	3,803	-37,979	14,369
Total Comprehensive Income	$12,229	$23,247	$31,119	$69,127

Unaudited_Condensed_Consolidat4

Unaudited Condensed Consolidated Statements of Changes in Stockholders' Equity (USD $)	Total	Common Stock	Paid-in Capital	Retained Earnings Substantially Restricted	Accumulated Other Comprehensive Income
In Thousands, except Share data
Balance, beginning at Dec. 31, 2011	$850,227	$719	$642,882	$173,139	$33,487
Balance, beginning, shares at Dec. 31, 2011	'	71,915,073	'	'	'
Net income	54,758	'	'	54,758	'
Comprehensive income (loss), accumulated other comprehensive income	14,369	'	'	'	14,369
Comprehensive income, total	69,127	'	'	'	'
Cash dividends declared	-28,052	'	'	-28,052	'
Stock issuances under stock incentive plans, shares	'	22,149	'	'	'
Stock issuances under stock incentive plans, value	323	0	323	'	'
Stock-based compensation and related taxes	-1,468	'	-1,468	'	'
Balance, ending at Sep. 30, 2012	890,157	719	641,737	199,845	47,856
Balance, ending, shares at Sep. 30, 2012	'	71,937,222	'	'	'
Balance, beginning at Dec. 31, 2012	900,949	719	641,737	210,531	47,962
Balance, beginning, shares at Dec. 31, 2012	71,937,222	71,937,222	'	'	'
Net income	69,098	'	'	69,098	'
Comprehensive income (loss), accumulated other comprehensive income	-37,979	'	'	'	-37,979
Comprehensive income, total	31,119	'	'	'	'
Cash dividends declared	-32,299	'	'	-32,299	'
Stock issuances under stock incentive plans, shares	'	227,597	'	'	'
Stock issuances under stock incentive plans, value	3,502	2	3,500	'	'
Stock issued in connection with acquisitions, shares	'	2,143,132	'	'	'
Stock issued in connection with acquisitions, value	45,034	22	45,012	'	'
Stock-based compensation and related taxes	-498	'	-498	'	'
Balance, ending at Sep. 30, 2013	$947,807	$743	$689,751	$247,330	$9,983
Balance, ending, shares at Sep. 30, 2013	74,307,951	74,307,951	'	'	'

Unaudited_Condensed_Consolidat5

Unaudited Condensed Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) (USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Cash dividends declared per share	$0.44	$0.39
Retained Earnings Substantially Restricted	'	'
Cash dividends declared per share	$0.44	$0.39

Unaudited_Condensed_Consolidat6

Unaudited Condensed Consolidated Statements of Cash Flows (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Operating Activities	'	'
Net income	$69,098	$54,758
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Provision for loan losses	5,085	19,250
Net amortization of investment securities premiums and discounts	55,043	48,712
Federal Home Loan Bank stock dividends	0	-5
Mortgage loans held for sale originated or acquired	-760,860	-844,155
Proceeds from sales of mortgage loans held for sale	904,066	872,659
Gain on sale of loans	-23,582	-23,063
Loss on sale of investments	299	0
Stock-based compensation expense, net of tax benefits	800	255
Excess tax deficiencies from stock-based compensation	219	8
Depreciation of premises and equipment	7,408	7,384
Loss on sale of other real estate owned and writedown, net	1,276	11,671
Amortization of core deposit intangibles	1,684	1,619
Net increase in accrued interest receivable	-2,628	-4,398
Net decrease (increase) in other assets	3,459	-3,649
Net decrease in accrued interest payable	-1,290	-1,172
Net increase in other liabilities	12,526	13,082
Net cash provided by operating activities	272,603	152,956
Investing Activities	'	'
Proceeds from sales, maturities and prepayments of investment securities, available-for-sale	1,676,928	1,397,533
Purchases of investment securities, available-for-sale	-1,321,504	-1,873,893
Principal collected on loans	854,553	706,240
Loans originated or acquired	-1,121,384	-716,729
Net addition of premises and equipment and other real estate owned	-6,861	-7,896
Proceeds from sale of other real estate owned	18,131	28,483
Net sale (purchase) of non-marketable equity securities	583	-664
Net cash received from acquisitions	26,155	0
Net cash provided by (used in) investment activities	126,601	-466,926
Financing Activities	'	'
Net (decrease) increase in deposits	-301,759	381,884
Net increase in securities sold under agreements to repurchase	24,805	156,193
Net decrease in Federal Home Loan Bank advances	-35,098	-152,025
Net (decrease) increase in federal funds purchased and other borrowed funds	-1,458	264
Cash dividends paid	-21,153	-28,052
Excess tax deficiencies from stock-based compensation	-219	-8
Proceeds from stock options exercised	3,322	81
Net cash (used in) provided by financing activities	-331,560	358,337
Net increase in cash and cash equivalents	67,644	44,367
Cash and cash equivalents at beginning of period	187,040	128,032
Cash and cash equivalents at end of period	254,684	172,399
Supplemental Disclosure of Cash Flow Information	'	'
Cash paid during the period for interest	23,120	28,721
Cash paid during the period for income taxes	17,283	18,081
Supplemental Disclosure of Non-Cash Investing Activities	'	'
Sale and refinancing of other real estate owned	3,549	1,578
Transfer of loans to other real estate owned	13,091	21,029
Fair value of common stock shares issued	45,033	0
Cash consideration for outstanding shares	24,858	0
Fair value of assets acquired	630,569	0
Liabilities assumed	$560,678	$0

Nature_of_Operations_and_Summa

Nature of Operations and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Nature of Operations and Summary of Significant Accounting Policies	'
	Note 1. Nature of Operations and Summary of Significant Accounting Policies
	General
	Glacier Bancorp, Inc. (“Company”) is a Montana corporation headquartered in Kalispell, Montana. The Company provides a full range of banking services to individual and corporate customers in Montana, Idaho, Wyoming, Colorado, Utah and Washington through thirteen divisions of its wholly-owned bank subsidiary, Glacier Bank (“Bank”). The Company offers a wide range of banking products and services, including transaction and savings deposits, real estate, commercial, agriculture and consumer loans, mortgage origination services, and retail brokerage services. The Company serves individuals, small to medium-sized businesses, community organizations and public entities.
	In the opinion of management, the accompanying unaudited condensed consolidated financial statements contain all adjustments (consisting of normal recurring adjustments) necessary for a fair presentation of the Company’s financial condition as of September 30, 2013, the results of operations and comprehensive income for the three and nine month periods ended September 30, 2013 and 2012, and changes in stockholders’ equity and cash flows for the nine month periods ended September 30, 2013 and 2012. The condensed consolidated statement of financial condition of the Company as of December 31, 2012 has been derived from the audited consolidated statements of the Company as of that date.
	The accompanying unaudited condensed consolidated financial statements do not include all of the information and footnotes required by accounting principles generally accepted in the United States of America (“GAAP”) for complete financial statements. These unaudited condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2012. Operating results for the nine months ended September 30, 2013 are not necessarily indicative of the results anticipated for the year ending December 31, 2013.
	The Company is a defendant in legal proceedings arising in the normal course of business. In the opinion of management, the disposition of pending litigation will not have a material affect on the Company’s consolidated financial position, results of operations or liquidity.
	Material estimates that are particularly susceptible to significant change include the determination of the allowance for loan and lease losses (“ALLL” or “allowance”) and the valuations related to investments and real estate acquired in connection with foreclosures or in satisfaction of loans. For the determination of the ALLL and real estate valuation estimates, management obtains independent appraisals (new or updated) for significant items. Estimates relating to investment valuations are obtained from independent third parties.
	Principles of Consolidation
	The consolidated financial statements of the Company include the parent holding company and the Bank. The Bank consists of thirteen bank divisions, a treasury division and an information technology division. Each of the bank divisions operate under separate names, management teams and directors. The Company considers the Bank to be its sole operating segment as the Bank 1) engages in similar bank business activity from which it earns revenues and incurs expenses, 2) the operating results of the Bank are regularly reviewed by the Chief Executive Officer (i.e., the chief operating decision maker) who makes decisions about resources to be allocated to the Bank, and 3) financial information is available for the Bank. All significant inter-company transactions have been eliminated in consolidation.
	On May 31, 2013, the Company completed its acquisition of Wheatland Bankshares, Inc. (“Wheatland”) and its wholly-owned subsidiary, First State Bank, a community bank based in Wheatland, Wyoming. On July 31, 2013, the Company completed its acquisition of North Cascades Bancshares, Inc. (“NCBI”) and its wholly-owned subsidiary, North Cascades National Bank, a community bank based in Chelan, Washington. Both transactions were accounted for using the acquisition method, and their results of operations have been included in the Company’s consolidated financial statements as of the acquisition dates.
	The Company formed GBCI Other Real Estate (“GORE”) to isolate certain bank foreclosed properties for legal protection and administrative purposes and the remaining properties are currently held for sale. GORE is included in the Bank operating segment due to its insignificant activity.
	The Company owns the following trust subsidiaries, each of which issued trust preferred securities as Tier 1 capital instruments: Glacier Capital Trust II, Glacier Capital Trust III, Glacier Capital Trust IV, Citizens (ID) Statutory Trust I, Bank of the San Juans Bancorporation Trust I, First Company Statutory Trust 2001 and First Company Statutory Trust 2003. The trust subsidiaries are not included in the Company’s consolidated financial statements.
	Variable Interest Entities
	The Company has equity investments in Certified Development Entities (“CDE”) which have received allocations of New Markets Tax Credits (“NMTC”). The Company also has equity investments in Low-Income Housing Tax Credit (“LIHTC”) partnerships. The CDEs and the LIHTC partnerships are variable interest entities (“VIE”).
	The following table summarizes the carrying amounts of the VIE’s assets and liabilities included in the Company’s consolidated financial statements at September 30, 2013 and December 31, 2012:
		30-Sep-13			31-Dec-12
	(Dollars in thousands)	CDE (NMTC)		LIHTC	CDE (NMTC)	LIHTC
	Assets
	Loans receivable	$	35,956	—	35,480	—
	Premises and equipment, net	—		13,641	—	16,066
	Accrued interest receivable	113		—	117	—
	Other assets	903		153	1,114	143
	Total assets	$	36,972	13,794	36,711	16,209
	Liabilities
	Other borrowed funds	$	4,555	1,723	4,555	3,639
	Accrued interest payable	4		5	4	6
	Other liabilities	92		203	182	136
	Total liabilities	$	4,651	1,931	4,741	3,781
	Amounts presented in the table above are adjusted for intercompany eliminations. All assets presented can be used only to settle obligations of the consolidated VIEs and all liabilities presented consist of liabilities for which creditors and other beneficial interest holders therein have no recourse to the general credit of the Company.
	Loans Receivable
	Loans that are intended to be held-to-maturity are reported at the unpaid principal balance less net charge-offs and adjusted for deferred fees and costs on originated loans and unamortized premiums or discounts on acquired loans. Fees and costs on originated loans and premiums or discounts on acquired loans are deferred and subsequently amortized or accreted as a yield adjustment over the expected life of the loan utilizing the interest method. The objective of the interest method is to calculate periodic interest income at a constant effective yield. When a loan is paid off prior to maturity, the remaining fees and costs on originated loans and premiums or discounts on acquired loans are immediately recognized into interest income.
	The Company’s loan segments, which are based on the purpose of the loan, include residential real estate, commercial, and consumer loans. The Company’s loan classes, a further disaggregation of segments, include residential real estate loans (residential real estate segment), commercial real estate and other commercial loans (commercial segment), and home equity and other consumer loans (consumer segment).
	Loans that are thirty days or more past due based on payments received and applied to the loan are considered delinquent. Loans are designated non-accrual and the accrual of interest is discontinued when the collection of the contractual principal or interest is unlikely. A loan is typically placed on non-accrual when principal or interest is due and has remained unpaid for ninety days or more. When a loan is placed on non-accrual status, interest previously accrued but not collected is reversed against current period interest income. Subsequent payments are applied to the outstanding principal balance if doubt remains as to the ultimate collectability of the loan. Interest accruals are not resumed on partially charged-off impaired loans. For other loans on nonaccrual, interest accruals are resumed on such loans only when they are brought fully current with respect to interest and principal and when, in the judgment of management, the loans are estimated to be fully collectible as to both principal and interest.
	The Company considers impaired loans to be the primary credit quality indicator for monitoring the credit quality of the loan portfolio. Loans are designated impaired when, based upon current information and events, it is probable that the Company will be unable to collect the scheduled payments of principal or interest when due according to the contractual terms of the loan agreement and therefore, the Company has serious doubts as to the ability of such borrowers to fulfill the contractual obligation. Impaired loans include non-performing loans (i.e., non-accrual loans and accruing loans ninety days or more past due) and accruing loans under ninety days past due where it is probable payments will not be received according to the loan agreement (e.g., troubled debt restructuring). Interest income on accruing impaired loans is recognized using the interest method. The Company measures impairment on a loan-by-loan basis in the same manner for each class within the loan portfolio. An insignificant delay or shortfall in the amounts of payments would not cause a loan or lease to be considered impaired. The Company determines the significance of payment delays and shortfalls on a case-by-case basis, taking into consideration all of the facts and circumstances surrounding the loan and the borrower, including the length and reasons for the delay, the borrower’s prior payment record, and the amount of the shortfall in relation to the principal and interest due.
	A restructured loan is considered a troubled debt restructuring (“TDR”) if the creditor, for economic or legal reasons related to the debtor’s financial difficulties, grants a concession to the debtor that it would not otherwise consider. A TDR loan is considered an impaired loan and a specific valuation allowance is established when the fair value of the collateral-dependent loan or present value of the loan’s expected future cash flows (discounted at the loan’s effective interest rate based on the original contractual rate) is lower than the carrying value of the impaired loan. The Company made the following types of loan modifications, some of which were considered a TDR:
	•	Reduction of the stated interest rate for the remaining term of the debt;
	•	Extension of the maturity date(s) at a stated rate of interest lower than the current market rate for newly originated debt having similar risk characteristics; and
	•	Reduction of the face amount of the debt as stated in the debt agreements.
	The Company recognizes that while borrowers may experience deterioration in their financial condition, many continue to be creditworthy customers who have the willingness and capacity for debt repayment. In determining whether non-restructured or unimpaired loans issued to a single or related party group of borrowers should continue to accrue interest when the borrower has other loans that are impaired or are TDRs, the Company on a quarterly or more frequent basis performs an updated and comprehensive assessment of the willingness and capacity of the borrowers to timely and ultimately repay their total debt obligations, including contingent obligations. Such analysis takes into account current financial information about the borrowers and financially responsible guarantors, if any, including for example:
	•	analysis of global, i.e., aggregate debt service for total debt obligations;
	•	assessment of the value and security protection of collateral pledged using current market conditions and alternative market assumptions across a variety of potential future situations; and
	•	loan structures and related covenants.
	For additional information relating to loans, see Note 3.
	Allowance for Loan and Lease Losses
	Based upon management’s analysis of the Company’s loan portfolio, the balance of the ALLL is an estimate of probable credit losses known and inherent within the Bank’s loan portfolio as of the date of the consolidated financial statements. The ALLL is analyzed at the loan class level and is maintained within a range of estimated losses. Determining the adequacy of the ALLL involves a high degree of judgment and is inevitably imprecise as the risk of loss is difficult to quantify. The determination of the ALLL and the related provision for loan losses is a critical accounting estimate that involves management’s judgments about all known relevant internal and external environmental factors that affect loan losses. The balance of the ALLL is highly dependent upon management’s evaluations of borrowers’ current and prospective performance, appraisals and other variables affecting the quality of the loan portfolio. Individually significant loans and major lending areas are reviewed periodically to determine potential problems at an early date. Changes in management’s estimates and assumptions are reasonably possible and may have a material impact upon the Company’s consolidated financial statements, results of operations or capital.
	The ALLL consists of a specific valuation allowance component and a general valuation allowance component. The specific component relates to loans that are determined to be impaired and individually evaluated for impairment. The Company measures impairment on a loan-by-loan basis based on the present value of expected future cash flows discounted at the loan’s effective interest rate, except when it is determined that repayment of the loan is expected to be provided solely by the underlying collateral. For impairment based on expected future cash flows, the Company considers all information available as of a measurement date, including past events, current conditions, potential prepayments, and estimated cost to sell when such costs are expected to reduce the cash flows available to repay or otherwise satisfy the loan. For alternative ranges of cash flows, the likelihood of the possible outcomes is considered in determining the best estimate of expected future cash flows. The effective interest rate for a loan restructured in a TDR is based on the original contractual rate. For collateral-dependent loans and real estate loans for which foreclosure or a deed-in-lieu of foreclosure is probable, impairment is measured by the fair value of the collateral, less estimated cost to sell. The fair value of the collateral is determined primarily based upon appraisal or evaluation of the underlying real property value.
	The general valuation allowance component relates to probable credit losses inherent in the balance of the loan portfolio based on historical loss experience, adjusted for changes in trends and conditions of qualitative or environmental factors. The historical loss experience is based on the previous twelve quarters loss experience by loan class adjusted for risk characteristics in the existing loan portfolio. The same trends and conditions are evaluated for each class within the loan portfolio; however, the risk characteristics are weighted separately at the individual class level based on the Company’s judgment and experience.
	The changes in trends and conditions of certain items include the following:
	•	Changes in lending policies and procedures, including changes in underwriting standards and collection, charge-off, and recovery practices not considered elsewhere in estimating credit losses;
	•	Changes in international, national, regional, and local economic and business conditions and developments that affect the collectability of the portfolio, including the condition of various market segments;
	•	Changes in the nature and volume of the portfolio and in the terms of loans;
	•	Changes in experience, ability, and depth of lending management and other relevant staff;
	•	Changes in the volume and severity of past due and nonaccrual loans;
	•	Changes in the quality of the Company’s loan review system;
	•	Changes in the value of underlying collateral for collateral-dependent loans;
	•	The existence and effect of any concentrations of credit, and changes in the level of such concentrations; and
	•	The effect of other external factors such as competition and legal and regulatory requirements on the level of estimated credit losses in the Company’s existing portfolio.
	The ALLL is increased by provisions for loan losses which are charged to expense. The portions of loan balances determined by management to be uncollectible are charged-off as a reduction of the ALLL and recoveries of amounts previously charged-off are credited as an increase to the ALLL. The Company’s charge-off policy is consistent with bank regulatory standards. Consumer loans generally are charged off when the loan becomes over 120 days delinquent. Real estate acquired as a result of foreclosure or by deed-in-lieu of foreclosure is classified as real estate owned until such time as it is sold.
	At acquisition date, the assets and liabilities of acquired banks are recorded at their estimated fair values which results in no ALLL carried over from acquired banks. Subsequent to acquisition, an allowance will be recorded on the acquired loan portfolios for further credit deterioration, if any.
	Impact of Recent Authoritative Accounting Guidance
	The Accounting Standards Codification™ (“ASC”) is the Financial Accounting Standards Board’s (“FASB”) officially recognized source of authoritative GAAP applicable to all public and non-public non-governmental entities. Rules and interpretive releases of the Securities and Exchange Commission (“SEC”) under the authority of the federal securities laws are also sources of authoritative GAAP for the Company as an SEC registrant. All other accounting literature is non-authoritative.
	In June 2011, FASB amended FASB ASC Topic 220, Comprehensive Income. The amendment provides an entity the option to present the total of comprehensive income, the components of net income, and the components of other comprehensive income either in a single continuous statement or in two separate but consecutive statements. Accounting Standards Update (“ASU”) No. 2011-12, Comprehensive Income (Topic 220) deferred the specific requirement of the amendment to present items that are reclassified from accumulated other comprehensive income to net income separately with their respective components of net income and other comprehensive income. The amendments were effective retrospectively during interim and annual periods beginning after December 15, 2011. ASU No. 2013-2, Comprehensive Income (Topic 220) reversed the deferment of ASU 2011-12 and will be effective prospectively for reporting periods beginning after December 15, 2012 and early adoption is permitted. The Company early adopted ASU No. 2013-2 as of December 31, 2012. The Company has evaluated the impact of the adoption of these amendments and determined there was not a material effect on the Company’s financial position or results of operations.

Investment_Securities_Availabl

Investment Securities, Available-for-Sale	9 Months Ended
	Sep. 30, 2013
Investments, Debt and Equity Securities [Abstract]	'
Investment Securities, Available-for-Sale	'
	Note 2. Investment Securities, Available-for-Sale
	A comparison of the amortized cost and estimated fair value of the Company’s investment securities designated as available-for-sale is presented below.
		30-Sep-13
		Weighted			Amortized			Gross Unrealized				Fair
	(Dollars in thousands)	Yield			Cost			Gains		Losses		Value
	U.S. government sponsored enterprises
	Maturing after one year through five years	2.29	%		$	11,278		240		—		11,518
	Maturing after five years through ten years	1.82	%		38			—		—		38
		2.29	%		11,316			240		—		11,556
	State and local governments
	Maturing within one year	2.18	%		6,059			52		—		6,111
	Maturing after one year through five years	2.1	%		162,569			3,096		(431	)	165,234
	Maturing after five years through ten years	3.17	%		57,892			1,122		(832	)	58,182
	Maturing after ten years	4.46	%		1,104,890			28,571		(21,604	)	1,111,857
		4.1	%		1,331,410			32,841		(22,867	)	1,341,384
	Corporate bonds
	Maturing within one year	2.1	%		73,064			736		—		73,800
	Maturing after one year through five years	2.1	%		358,034			2,890		(2,852	)	358,072
	Maturing after five years through ten years	2.22	%		11,058			—		(85	)	10,973
		2.1	%		442,156			3,626		(2,937	)	442,845
	Residential mortgage-backed securities	2.44	%		1,515,728			15,357		(7,917	)	1,523,168
	Total investment securities	3.06	%		$	3,300,610		52,064		(33,721	)	3,318,953
		31-Dec-12
		Weighted			Amortized			Gross Unrealized				Fair
	(Dollars in thousands)	Yield			Cost			Gains		Losses		Value
	U.S. government and federal agency
	Maturing within one year	1.62	%		$	201		1		—		202
	U.S. government sponsored enterprises
	Maturing after one year through five years	2.3	%		17,064			371		—		17,435
	Maturing after five years through ten years	2.03	%		44			1		—		45
		2.29	%		17,108			372		—		17,480
	State and local governments
	Maturing within one year	2.01	%		4,288			28		(2	)	4,314
	Maturing after one year through five years	2.11	%		149,497			4,142		(142	)	153,497
	Maturing after five years through ten years	2.95	%		38,346			1,102		(99	)	39,349
	Maturing after ten years	4.7	%		935,897			82,823		(1,362	)	1,017,358
		4.29	%		1,128,028			88,095		(1,605	)	1,214,518
	Corporate bonds
	Maturing within one year	1.73	%		18,412			51		—		18,463
	Maturing after one year through five years	2.22	%		250,027			4,018		(238	)	253,807
	Maturing after five years through ten years	2.23	%		16,144			381		—		16,525
		2.19	%		284,583			4,450		(238	)	288,795
	Collateralized debt obligations
	Maturing after ten years	8.03	%		1,708			—		—		1,708
	Residential mortgage-backed securities	1.95	%		2,156,049			8,860		(4,607	)	2,160,302
	Total investment securities	2.71	%		$	3,587,677		101,778		(6,450	)	3,683,005
	Included in the residential mortgage-backed securities are $3,214,000 and $46,733,000 as of September 30, 2013 and December 31, 2012, respectively, of non-guaranteed private label whole loan mortgage-backed securities of which none of the underlying collateral is considered “subprime.”
	Maturities of securities do not reflect repricing opportunities present in adjustable rate securities, nor do they reflect expected shorter maturities based upon early prepayment of principal. Weighted average yields are based on the interest method taking into account premium amortization, discount accretion and mortgage-backed securities’ prepayment provisions. Weighted average yields on tax-exempt investment securities exclude the federal income tax benefit.
	The cost of each investment sold is determined by specific identification. Gain or loss on sale of investments consists of the following:
		Three Months ended						Nine Months ended
	(Dollars in thousands)	September 30,				September 30,		September 30,		September 30,
		2013				2012		2013		2012
	Gross proceeds	$	102,483			—		181,971		—
	Less amortized cost	(102,886		)		—		(182,270	)	—
	Net loss on sale of investments	$	(403	)		—		(299	)	—
	Gross gain on sale of investments	$	3,467			—		3,723		—
	Gross loss on sale of investments	(3,870		)		—		(4,022	)	—
	Net loss on sale of investments	$	(403	)		—		(299	)	—
	Investments with an unrealized loss position are summarized as follows:
		30-Sep-13
		Less than 12 Months						12 Months or More				Total
	(Dollars in thousands)	Fair				Unrealized		Fair		Unrealized		Fair	Unrealized
		Value				Loss		Value		Loss		Value	Loss
State and local governments	$	405,834			(21,121	)	22,373		(1,746	)	428,207	(22,867	)
Corporate bonds	189,130				(2,937	)	—		—		189,130	(2,937	)
Residential mortgage-backed securities	446,642				(7,917	)	—		—		446,642	(7,917	)
Total temporarily impaired securities	$	1,041,606			(31,975	)	22,373		(1,746	)	1,063,979	(33,721	)
	31-Dec-12
	Less than 12 Months						12 Months or More				Total
(Dollars in thousands)	Fair				Unrealized		Fair		Unrealized		Fair	Unrealized
	Value				Loss		Value		Loss		Value	Loss
State and local governments	$	102,896			(1,531	)	4,533		(74	)	107,429	(1,605	)
Corporate bonds	41,856				(238	)	—		—		41,856	(238	)
Residential mortgage-backed securities	955,235				(4,041	)	62,905		(566	)	1,018,140	(4,607	)
Total temporarily impaired securities	$	1,099,987			(5,810	)	67,438		(640	)	1,167,425	(6,450	)
With respect to the Company’s review of its securities in an unrealized loss position at September 30, 2013, management determined that it did not intend to sell and there was no expected requirement to sell any of its temporarily impaired securities. Based on an analysis of its impaired securities as of September 30, 2013 and December 31, 2012, the Company determined that none of such securities had other-than-temporary impairment.

Loans_Receivable_Net

Loans Receivable, Net	9 Months Ended
	Sep. 30, 2013
Receivables [Abstract]	'
Loans Receivable, Net	'
	Note 3. Loans Receivable, Net
	The following schedules summarize the activity in the ALLL on a portfolio class basis:
		Three Months ended September 30, 2013
	(Dollars in thousands)	Total			Residential		Commercial		Other		Home		Other
					Real Estate		Real Estate		Commercial		Equity		Consumer
	Allowance for loan and lease losses
	Balance at beginning of period	$	130,883		14,797		73,885		24,116		9,626		8,459
	Provision for loan losses	1,907			950		381		385		125		66
	Charge-offs	(3,077		)	(42	)	(1,235	)	(1,065	)	(333	)	(402	)
	Recoveries	1,052			45		367		385		73		182
	Balance at end of period	$	130,765		15,750		73,398		23,821		9,491		8,305
		Three Months ended September 30, 2012
	(Dollars in thousands)	Total			Residential		Commercial		Other		Home		Other
					Real Estate		Real Estate		Commercial		Equity		Consumer
	Allowance for loan and lease losses
	Balance at beginning of period	$	137,459		18,139		79,098		20,570		10,904		8,748
	Provision for loan losses	2,700			209		(1,210	)	2,859		(555	)	1,397
	Charge-offs	(5,052		)	(1,172	)	(586	)	(1,441	)	(1,044	)	(809	)
	Recoveries	1,553			73		453		241		679		107
	Balance at end of period	$	136,660		17,249		77,755		22,229		9,984		9,443
		Nine Months ended September 30, 2013
	(Dollars in thousands)	Total			Residential		Commercial		Other		Home		Other
					Real Estate		Real Estate		Commercial		Equity		Consumer
	Allowance for loan and lease losses
	Balance at beginning of period	$	130,854		15,482		74,398		21,567		10,659		8,748
	Provision for loan losses	5,085			464		(51	)	3,964		566		142
	Charge-offs	(8,962		)	(391	)	(2,538	)	(2,817	)	(1,962	)	(1,254	)
	Recoveries	3,788			195		1,589		1,107		228		669
	Balance at end of period	$	130,765		15,750		73,398		23,821		9,491		8,305
		Nine Months ended September 30, 2012
	(Dollars in thousands)	Total			Residential		Commercial		Other		Home		Other
					Real Estate		Real Estate		Commercial		Equity		Consumer
	Allowance for loan and lease losses
	Balance at beginning of period	$	137,516		17,227		76,920		20,833		13,616		8,920
	Provision for loan losses	19,250			2,294		11,800		4,163		(1,025	)	2,018
	Charge-offs	(24,789		)	(2,492	)	(13,120	)	(3,797	)	(3,402	)	(1,978	)
	Recoveries	4,683			220		2,155		1,030		795		483
	Balance at end of period	$	136,660		17,249		77,755		22,229		9,984		9,443
	The following schedules disclose the ALLL and loans receivable on a portfolio class basis:
		30-Sep-13
	(Dollars in thousands)	Total			Residential		Commercial		Other		Home		Other
					Real Estate		Real Estate		Commercial		Equity		Consumer
	Allowance for loan and lease losses
	Individually evaluated for impairment	$	12,728		1,088		6,662		3,810		109		1,059
	Collectively evaluated for impairment	118,037			14,662		66,736		20,011		9,382		7,246
	Total allowance for loan and lease losses	$	130,765		15,750		73,398		23,821		9,491		8,305
	Loans receivable
	Individually evaluated for impairment	$	206,918		27,104		125,566		38,390		10,091		5,767
	Collectively evaluated for impairment	3,794,181			556,713		1,868,492		795,839		363,421		209,716
	Total loans receivable	$	4,001,099		583,817		1,994,058		834,229		373,512		215,483
		31-Dec-12
	(Dollars in thousands)	Total			Residential		Commercial		Other		Home		Other
					Real Estate		Real Estate		Commercial		Equity		Consumer
	Allowance for loan and lease losses
	Individually evaluated for impairment	$	15,534		1,680		7,716		3,859		870		1,409
	Collectively evaluated for impairment	115,320			13,802		66,682		17,708		9,789		7,339
	Total allowance for loan and lease losses	$	130,854		15,482		74,398		21,567		10,659		8,748
	Loans receivable
	Individually evaluated for impairment	$	201,735		25,862		125,282		33,593		11,074		5,924
	Collectively evaluated for impairment	3,195,690			490,605		1,530,226		589,804		392,851		192,204
	Total loans receivable	$	3,397,425		516,467		1,655,508		623,397		403,925		198,128
	Substantially all of the Company’s loan receivables are with customers in the Company’s geographic market areas. Although the Company has a diversified loan portfolio, a substantial portion of its customers’ ability to honor their obligations is dependent upon the economic performance in the Company’s market areas. Net deferred fees, costs, premiums, and discounts of $10,870,000 and $1,379,000 were included in the loans receivable balance at September 30, 2013 and December 31, 2012, respectively.
	The following schedules disclose the impaired loans by portfolio class basis:
	At or for the Three or Nine Months ended September 30, 2013
(Dollars in thousands)	Total			Residential		Commercial		Other		Home		Other
				Real Estate		Real Estate		Commercial		Equity		Consumer
Loans with a specific valuation allowance
Recorded balance	$	62,614		7,887		28,194		22,368		673		3,492
Unpaid principal balance	64,969			8,032		29,463		22,986		717		3,771
Specific valuation allowance	12,728			1,088		6,662		3,810		109		1,059
Average balance - three months	59,817			7,431		26,525		21,780		495		3,586
Average balance - nine months	59,402			7,237		26,653		21,321		737		3,454
Loans without a specific valuation allowance
Recorded balance	$	144,304		19,217		97,372		16,022		9,418		2,275
Unpaid principal balance	174,258			20,681		120,914		19,233		11,026		2,404
Average balance - three months	139,928			18,481		95,175		15,768		8,766		1,738
Average balance - nine months	139,368			18,420		95,857		14,011		9,017		2,063
Totals
Recorded balance	$	206,918		27,104		125,566		38,390		10,091		5,767
Unpaid principal balance	239,227			28,713		150,377		42,219		11,743		6,175
Specific valuation allowance	12,728			1,088		6,662		3,810		109		1,059
Average balance - three months	199,745			25,912		121,700		37,548		9,261		5,324
Average balance - nine months	198,770			25,657		122,510		35,332		9,754		5,517
	At or for the Year ended December 31, 2012
(Dollars in thousands)	Total			Residential		Commercial		Other		Home		Other
				Real Estate		Real Estate		Commercial		Equity		Consumer
Loans with a specific valuation allowance
Recorded balance	$	62,759		7,334		29,595		21,205		1,354		3,271
Unpaid principal balance	70,261			7,459		36,887		21,278		1,362		3,275
Specific valuation allowance	15,534			1,680		7,716		3,859		870		1,409
Average balance	76,656			12,797		36,164		22,665		1,390		3,640
Loans without a specific valuation allowance
Recorded balance	$	138,976		18,528		95,687		12,388		9,720		2,653
Unpaid principal balance	149,412			19,613		102,798		14,318		9,965		2,718
Average balance	162,505			16,034		111,554		19,733		11,993		3,191
Totals
Recorded balance	$	201,735		25,862		125,282		33,593		11,074		5,924
Unpaid principal balance	219,673			27,072		139,685		35,596		11,327		5,993
Specific valuation allowance	15,534			1,680		7,716		3,859		870		1,409
Average balance	239,161			28,831		147,718		42,398		13,383		6,831
Interest income recognized on impaired loans for the periods ended September 30, 2013 and December 31, 2012 was not significant.
The following is a loans receivable aging analysis on a portfolio class basis:
	30-Sep-13
(Dollars in thousands)	Total			Residential		Commercial		Other		Home		Other
				Real Estate		Real Estate		Commercial		Equity		Consumer
Accruing loans 30-59 days past due	$	21,294		516		11,829		5,854		1,828		1,267
Accruing loans 60-89 days past due	5,107			824		2,419		683		797		384
Accruing loans 90 days or more past due	174			—		109		35		28		2
Non-accrual loans	88,293			12,604		53,536		11,591		8,953		1,609
Total past due and non-accrual loans	114,868			13,944		67,893		18,163		11,606		3,262
Current loans receivable	3,886,231			569,873		1,926,165		816,066		361,906		212,221
Total loans receivable	$	4,001,099		583,817		1,994,058		834,229		373,512		215,483
	December 31, 2012
(Dollars in thousands)	Total			Residential		Commercial		Other		Home		Other
				Real Estate		Real Estate		Commercial		Equity		Consumer
Accruing loans 30-59 days past due	$	17,454		3,897		7,424		2,020		2,872		1,241
Accruing loans 60-89 days past due	9,643			1,870		3,745		645		2,980		403
Accruing loans 90 days or more past due	1,479			451		594		197		188		49
Non-accrual loans	96,933			14,237		55,687		13,200		11,241		2,568
Total past due and non-accrual loans	125,509			20,455		67,450		16,062		17,281		4,261
Current loans receivable	3,271,916			496,012		1,588,058		607,335		386,644		193,867
Total loans receivable	$	3,397,425		516,467		1,655,508		623,397		403,925		198,128
The following is a summary of the TDRs that occurred during the periods presented and the TDRs that occurred within the previous twelve months that subsequently defaulted during the periods presented on a portfolio class basis:
	Three Months ended September 30, 2013
(Dollars in thousands)	Total			Residential		Commercial		Other		Home		Other
				Real Estate		Real Estate		Commercial		Equity		Consumer
Troubled debt restructurings
Number of loans	9			2		4		—		1		2
Pre-modification recorded balance	$	2,926		284		2,481		—		57		104
Post-modification recorded balance	$	3,141		499		2,481		—		57		104
Troubled debt restructurings that subsequently defaulted
Number of loans	2			—		—		2		—		—
Recorded balance	$	363		—		—		363		—		—
	Three Months ended September 30, 2012
(Dollars in thousands)	Total			Residential		Commercial		Other		Home		Other
				Real Estate		Real Estate		Commercial		Equity		Consumer
Troubled debt restructurings
Number of loans	46			1		21		19		2		3
Pre-modification recorded balance	$	38,125		280		20,866		16,601		219		159
Post-modification recorded balance	$	35,475		281		18,242		16,571		222		159
Troubled debt restructurings that subsequently defaulted
Number of loans	3			2		—		—		1		—
Recorded balance	$	1,792		1,622		—		—		170		—
	Nine Months ended September 30, 2013
(Dollars in thousands)	Total			Residential		Commercial		Other		Home		Other
				Real Estate		Real Estate		Commercial		Equity		Consumer
Troubled debt restructurings
Number of loans	50			9		17		17		2		5
Pre-modification recorded balance	$	12,016		1,907		7,137		2,572		147		253
Post-modification recorded balance	$	12,418		2,293		7,137		2,588		147		253
Troubled debt restructurings that subsequently defaulted
Number of loans	10			1		4		5		—		—
Recorded balance	$	2,772		265		1,918		589		—		—
	Nine Months ended September 30, 2012
(Dollars in thousands)	Total			Residential		Commercial		Other		Home		Other
				Real Estate		Real Estate		Commercial		Equity		Consumer
Troubled debt restructurings
Number of loans	149			9		61		60		9		10
Pre-modification recorded balance	$	66,580		1,981		37,712		25,033		1,314		540
Post-modification recorded balance	$	61,944		1,982		33,080		25,025		1,317		540
Troubled debt restructurings that subsequently defaulted
Number of loans	17			2		10		3		1		1
Recorded balance	$	10,204		1,622		7,553		801		170		58
For the nine months ended September 30, 2013 and 2012, the majority of TDRs occurring in most loan classes was a result of an extension of the maturity date which aggregated 59 percent and 56 percent, respectively, of total TDRs. For commercial real estate, the class with the largest dollar amount of TDRs, approximately 63 percent and 44 percent, respectively, was a result of an extension of the maturity date and 25 percent and 24 percent, respectively, was due to a combination of an interest rate reduction, extension of the maturity date, or reduction in the face amount.
In addition to the TDRs that occurred during the period provided in the preceding table, the Company had TDRs with pre-modification loan balances of $14,695,000 and $30,261,000 for the nine months ended September 30, 2013 and 2012, respectively, for which other real estate owned (“OREO”) was received in full or partial satisfaction of the loans. The majority of such TDRs for both periods was in commercial real estate.

Goodwill

Goodwill	9 Months Ended
	Sep. 30, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
Goodwill	'
	Note 4. Goodwill
	The Company performed its annual goodwill impairment test during the third quarter of 2013 and determined the fair value of the aggregated reporting units exceeded the carrying value, such that the Company’s goodwill was not considered impaired. Changes in the economic environment, operations of the aggregated reporting units, or other factors could result in the decline in the fair value of the aggregated reporting units which could result in a goodwill impairment in the future. For additional information on goodwill related to acquisitions, see Note 9.
	The following schedule discloses the changes in the carrying value of goodwill:
		Three Months ended					Nine Months ended
	(Dollars in thousands)	September 30,			September 30,		September 30,	September 30,
		2013			2012		2013	2012
	Net carrying value at beginning of period	$	119,509		106,100		106,100	106,100
	Acquisitions	10,197			—		23,606	—
	Net carrying value at end of period	$	129,706		106,100		129,706	106,100
	The gross carrying value of goodwill and the accumulated impairment charge consists of the following:
	(Dollars in thousands)	September 30,			December 31,
		2013			2012
	Gross carrying value	$	169,865		146,259
	Accumulated impairment charge	(40,159		)	(40,159	)
	Net carrying value	$	129,706		106,100

Derivatives_and_Hedging_Activi

Derivatives and Hedging Activities	9 Months Ended
	Sep. 30, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivatives and Hedging Activities	'
	Note 5. Derivatives and Hedging Activities
	As of September 30, 2013, the Company’s interest rate swap derivative financial instruments were designated as cash flow hedges and are summarized as follows:
	(Dollars in thousands)	Forecasted				Variable	Fixed		Term 2
		Notional  Amount				Interest Rate 1	Interest Rate 1
	Interest rate swap	$	160,000			3 month LIBOR	3.378	%	Oct. 21, 2014 - Oct. 21, 2021
	Interest rate swap	100,000				3 month LIBOR	2.498	%	Nov 30, 2015 - Nov. 30, 2022
	__________
	1 The Company pays the fixed interest rate and the counterparties pay the Company the variable interest rate.
	2 No cash will be exchanged prior to the term.
	The hedging strategy converts the LIBOR based variable interest rate on forecasted borrowings to a fixed interest rate, thereby protecting the Company from floating interest rate variability.
	The following table summarizes the fair value of the Company’s interest rate swap derivative financial instruments:
				Fair Value
	(Dollars in thousands)	Balance Sheet		September 30,			December 31,
		Location		2013			2012
	Interest rate swaps	Other liabilities		$	2,004		16,832
	Pursuant to the interest rate swap agreements, the Company pledged collateral to the counterparties in the form of investment securities totaling $7,856,000 at September 30, 2013. There was $0 collateral pledged from the counterparties to the Company as of September 30, 2013. There is the possibility that the Company may need to pledge additional collateral in the future if there were further declines in the fair value of the interest rate swap derivative financial instruments versus the collateral pledged.

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income	9 Months Ended
	Sep. 30, 2013
Equity [Abstract]	'
Accumulated Other Comprehensive Income	'
	Note 6. Accumulated Other Comprehensive Income
	The components of accumulated other comprehensive income, included in stockholders’ equity, are as follows:
	(Dollars in thousands)	September 30,			December 31,
		2013			2012
	Unrealized gains on available-for-sale securities	$	18,343		95,328
	Tax effect	(7,136		)	(37,083	)
	Net of tax amount	11,207			58,245
	Unrealized losses on derivatives used for cash flow hedges	(2,004		)	(16,832	)
	Tax effect	780			6,549
	Net of tax amount	(1,224		)	(10,283	)
	Total accumulated other comprehensive income	$	9,983		47,962

Earnings_Per_Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Earnings Per Share	'
	Note 7. Earnings Per Share
	Basic earnings per share is computed by dividing net income by the weighted average number of shares of common stock outstanding during the period presented. Diluted earnings per share is computed by including the net increase in shares as if dilutive outstanding stock options were exercised, using the treasury stock method.
	Basic and diluted earnings per share has been computed based on the following:
		Three Months ended			Nine Months ended
	(Dollars in thousands, except per share data)	September 30,		September 30,	September 30,	September 30,
		2013		2012	2013	2012
	Net income available to common stockholders, basic and diluted	$	25,628	19,444	69,098	54,758
	Average outstanding shares - basic	73,945,523		71,933,141	72,804,321	71,925,664
	Add: dilutive stock options and awards	76,348		40,844	65,154	97
	Average outstanding shares - diluted	74,021,871		71,973,985	72,869,475	71,925,761
	Basic earnings per share	$	0.35	0.27	0.95	0.76
	Diluted earnings per share	$	0.35	0.27	0.95	0.76
	There were 49,932 and 903,945 options excluded from the diluted average outstanding share calculation for the nine months ended September 30, 2013 and 2012, respectively, due to the option exercise price exceeding the market price of the Company’s common stock.

Fair_Value_of_Assets_and_Liabi

Fair Value of Assets and Liabilities	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Fair Value of Assets and Liabilities	'
	Note 8. Fair Value of Assets and Liabilities
	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 the assets or liabilities
	Transfers in and out of Level 1 (quoted prices in active markets), Level 2 (significant other observable inputs) and Level 3 (significant unobservable inputs) are recognized on the actual transfer date. There were no transfers between fair value hierarchy levels during the nine month periods ended September 30, 2013 and 2012.
	Recurring Measurements
	The following is a description of the inputs and valuation methodologies used for assets and liabilities measured at fair value on a recurring basis, as well as the general classification of such assets and liabilities pursuant to the valuation hierarchy. There have been no significant changes in the valuation techniques during the period ended September 30, 2013.
	Investment securities: fair value for available-for-sale securities is estimated by obtaining quoted market prices for identical assets, where available. If such prices are not available, fair value is based on independent asset pricing services and models, the inputs of which are market-based or independently sourced market parameters, including but not limited to, yield curves, interest rates, volatilities, prepayments, defaults, cumulative loss projections, and cash flows. Such securities are classified in Level 2 of the valuation hierarchy. Where Level 1 or Level 2 inputs are not available, such securities are classified as Level 3 within the hierarchy.
	Fair value determinations of investment securities are the responsibility of the Company’s corporate accounting department. The Company contracts with independent third party pricing vendors to generate fair value estimates and the Company reviews the vendors’ inputs for fair value estimates and the recommended assignments of levels within the fair value hierarchy on a quarterly basis. The review includes the extent to which markets for investment securities are determined to have limited or no activity, or are judged to be active markets. The Company reviews the extent to which observable and unobservable inputs are used as well as the appropriateness of the underlying assumptions about risk that a market participant would use in active markets, with adjustments for limited or inactive markets. In considering the inputs to the fair value estimates, the Company places less reliance on quotes that are judged to not reflect orderly transactions, or are non-binding indications. The Company makes independent inquiries of other knowledgeable parties in testing the reliability of the inputs, including consideration for illiquidity, credit risk, and cash flow estimates. In assessing credit risk, the Company reviews payment performance, collateral adequacy, credit rating histories, and issuers’ financial statements with follow-up discussion with issuers. For those markets determined to be inactive, the valuation techniques used are models for which management verifies that discount rates are appropriately adjusted to reflect illiquidity and credit risk. The Company also independently obtains cash flow estimates that are stressed at levels that exceed those used by the independent third party pricing vendors.
	Interest rate swap derivative financial instruments: fair values for interest rate swap derivative financial instruments 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 and, therefore, are classified within Level 2 of the valuation hierarchy. The inputs used to determine fair value include the 3 month LIBOR forward curve to estimate variable rate cash inflows and the spot LIBOR curve 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 Company also obtains and compares the reasonableness of the pricing from an independent party.
	The following schedules disclose the fair value measurement of assets and liabilities measured at fair value on a recurring basis:
				Fair Value Measurements
				At the End of the Reporting Period Using
	(Dollars in thousands)	Fair Value September 30, 2013		Quoted Prices		Significant		Significant
				in Active  Markets		Other		Unobservable
				for Identical		Observable		Inputs
				Assets		Inputs		(Level 3)
				(Level 1)		(Level 2)
	Investment securities, available-for-sale
	U.S. government sponsored enterprises	$	11,556	—		11,556		—
	State and local governments	1,341,384		—		1,341,384		—
	Corporate bonds	442,845		—		442,845		—
	Residential mortgage-backed securities	1,523,168		—		1,523,168		—
	Total assets measured at fair value on a recurring basis	$	3,318,953	—		3,318,953		—
	Interest rate swaps	$	2,004	—		2,004		—
	Total liabilities measured at fair value on a recurring basis	$	2,004	—		2,004		—
				Fair Value Measurements
				At the End of the Reporting Period Using
	(Dollars in thousands)	Fair Value December 31, 2012		Quoted Prices		Significant		Significant
				in Active  Markets		Other		Unobservable
				for Identical		Observable		Inputs
				Assets		Inputs		(Level 3)
				(Level 1)		(Level 2)
	Investment securities, available-for-sale
	U.S. government and federal agency	$	202	—		202		—
	U.S. government sponsored enterprises	17,480		—		17,480		—
	State and local governments	1,214,518		—		1,214,518		—
	Corporate bonds	288,795		—		288,795		—
	Collateralized debt obligations	1,708		—		1,708		—
	Residential mortgage-backed securities	2,160,302		—		2,160,302		—
	Total assets measured at fair value on a recurring basis	$	3,683,005	—		3,683,005		—
	Interest rate swaps	$	16,832	—		16,832		—
	Total liabilities measured at fair value on a recurring basis	$	16,832	—		16,832		—
	Non-recurring Measurements
	The following is a description of the inputs and valuation methodologies used for assets recorded at fair value on a non-recurring basis, as well as the general classification of such assets pursuant to the valuation hierarchy. There have been no significant changes in the valuation techniques during the period ended September 30, 2013.
	Other real estate owned: OREO is carried at the lower of fair value at acquisition date or estimated fair value, less estimated cost to sell. Estimated fair value of OREO is based on appraisals or evaluations (new or updated). OREO is classified within Level 3 of the fair value hierarchy.
	Collateral-dependent impaired loans, net of ALLL: loans included in the Company’s loan portfolio for which it is probable that the Company will not collect all principal and interest due according to contractual terms are considered impaired. Estimated fair value of collateral-dependent impaired loans is based on the fair value of the collateral, less estimated cost to sell. Collateral-dependent impaired loans are classified within Level 3 of the fair value hierarchy.
	The Company’s credit departments review appraisals for OREO and collateral-dependent loans, giving consideration to the highest and best use of the collateral. The appraisal or evaluation (new or updated) is considered the starting point for determining fair value. The valuation techniques used in preparing appraisals or evaluations (new or updated) include the cost approach, income approach, sales comparison approach, or a combination of the preceding valuation techniques. The key inputs used to determine the fair value of the collateral-dependent loans and OREO include selling costs, discounted cash flow rate or capitalization rate, and adjustment to comparables. Valuations and significant inputs obtained by independent sources are reviewed by the Company for accuracy and reasonableness. The Company also considers other factors and events in the environment that may affect the fair value. The appraisals or evaluations (new or updated) are reviewed at least quarterly and more frequently based on current market conditions, including deterioration in a borrower’s financial condition and when property values may be subject to significant volatility. After review and acceptance of the collateral appraisal or evaluation (new or updated), adjustments to the impaired loan or OREO may occur. The Company generally obtains appraisals or evaluations (new or updated) annually.
	The following schedules disclose the fair value measurement of assets with a recorded change during the period resulting from re-measuring the assets at fair value on a non-recurring basis:
				Fair Value Measurements
				At the End of the Reporting Period Using
	(Dollars in thousands)	Fair Value September 30, 2013		Quoted Prices		Significant		Significant
				in Active  Markets		Other		Unobservable
				for Identical		Observable		Inputs
				Assets		Inputs		(Level 3)
				(Level 1)		(Level 2)
	Other real estate owned	$	7,646	—		—		7,646
	Collateral-dependent impaired loans, net of ALLL	19,066		—		—		19,066
	Total assets measured at fair value on a non-recurring basis	$	26,712	—		—		26,712
				Fair Value Measurements
				At the End of the Reporting Period Using
	(Dollars in thousands)	Fair Value December 31, 2012		Quoted Prices		Significant		Significant
in Active  Markets				Other		Unobservable
for Identical				Observable		Inputs
Assets				Inputs		(Level 3)
(Level 1)				(Level 2)
Other real estate owned	$	13,983	—		—		13,983
Collateral-dependent impaired loans, net of ALLL	22,966		—		—		22,966
Total assets measured at fair value on a non-recurring basis	$	36,949	—		—		36,949
Non-recurring Measurements Using Significant Unobservable Inputs (Level 3)
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 value:
	Fair Value		Quantitative Information about Level 3 Fair Value Measurements
(Dollars in thousands)	September 30,		Valuation Technique	Unobservable Input		Range (Weighted Average) 1
	2013
Other real estate owned	$	6,828	Sales comparison approach	Selling costs		1.0% - 11.0% (7.0%)
				Adjustment to comparables		0.0% - 10.0% (0.0%)
	818		Combined approach	Selling costs		5.0% - 5.0% (5.0%)
				Adjustment to comparables		25.0% - 25.0% (25.0%)
	$	7,646
Collateral-dependent impaired loans, net of ALLL	$	442	Cost approach	Selling costs		10.0% - 50.0% (19.2%)
	2,553		Income approach	Selling costs		8.0% - 8.0% (8.0%)
				Discount rate		8.3% - 8.3% (8.3%)
	13,700		Sales comparison approach	Selling costs		0.0% - 10.0% (8.0%)
				Discount rate		0.0% - 0.0% (0.0%)
				Adjustment to comparables		0.0% - 1.0% (0.0%)
	2,371		Combined approach	Selling costs		8.0% - 8.0% (8.0%)
				Adjustment to comparables		10.0% - 36.0% (22.5%)
	$	19,066
__________
1 The range for selling costs and adjustments to comparables indicate reductions to the fair value.
Fair Value of Financial Instruments
The following is a description of the methods used to estimate the fair value of all other assets and liabilities recognized at amounts other than fair value.
Cash and cash equivalents: fair value is estimated at book value.
Loans held for sale: fair value is estimated at book value.
Loans receivable, net of ALLL: fair value is estimated by discounting the future cash flows using the rates at which similar notes would be written for the same remaining maturities. The market rates used are based on current rates the Company would impose for similar loans and reflect a market participant assumption about risks associated with non-performance, illiquidity, and the structure and term of the loans along with local economic and market conditions. Estimated fair value of impaired loans is based on the fair value of the collateral, less estimated cost to sell, or the present value of the loan’s expected future cash flows (discounted at the loan’s effective interest rate). All impaired loans are classified as Level 3 and all other loans are classified as Level 2 within the hierarchy.
Accrued interest receivable: fair value is estimated at book value.
Non-marketable equity securities: fair value is estimated at book value due to restrictions that limit the sale or transfer of such securities.
Deposits: fair value of term deposits is estimated by discounting the future cash flows using rates of similar deposits with similar maturities. The market rates used were obtained from a knowledgeable independent third party and reviewed by the Company. The rates were the average of current rates offered by the Company’s local competitors. The estimated fair value of demand, NOW, savings, and money market deposits is the book value since rates are regularly adjusted to market rates and transactions are executed at book value daily. Therefore, such deposits are classified in Level 1 of the valuation hierarchy. Certificate accounts and wholesale deposits are classified as Level 2 within the hierarchy.
Federal Home Loan Bank (“FHLB”) advances: fair value of non-callable FHLB advances is estimated by discounting the future cash flows using rates of similar advances with similar maturities. Such rates were obtained from current rates offered by FHLB. The estimated fair value of callable FHLB advances was obtained from FHLB and the model was reviewed by the Company, including discussions with FHLB.
Securities sold under agreements to repurchase (“repurchase agreements”) and other borrowed funds: fair value of term repurchase agreements and other term borrowings is estimated based on current repurchase rates and borrowing rates currently available to the Company for repurchases and borrowings with similar terms and maturities. The estimated fair value for overnight repurchase agreements and other borrowings is book value.
Subordinated debentures: fair value of the subordinated debt is estimated by discounting the estimated future cash flows using current estimated market rates. The market rates used were averages of currently traded trust preferred securities with similar characteristics to the Company’s issuances and obtained from an independent third party.
Accrued interest payable: fair value is estimated at book value.
Off-balance sheet financial instruments: commitments to extend credit and letters of credit represent the principal categories of off-balance sheet financial instruments. Rates for these commitments are set at time of loan closing, such that no adjustment is necessary to reflect these commitments at market value. The Company has an insignificant amount of off-balance sheet financial instruments.
The following schedules present the carrying amounts, estimated fair values and the level within the fair value hierarchy of the Company’s financial instruments:
			Fair Value Measurements
			At the End of the Reporting Period Using
(Dollars in thousands)	Carrying Amount September 30, 2013		Quoted Prices		Significant		Significant
			in Active  Markets		Other		Unobservable
			for Identical		Observable		Inputs
			Assets		Inputs		(Level 3)
			(Level 1)		(Level 2)
Financial assets
Cash and cash equivalents	$	254,684	254,684		—		—
Investment securities, available-for-sale	3,318,953		—		3,318,953		—
Loans held for sale	61,505		61,505		—		—
Loans receivable, net of ALLL	3,870,334		—		3,758,724		194,190
Accrued interest receivable	44,261		44,261		—		—
Non-marketable equity securities	52,192		—		52,192		—
Total financial assets	$	7,601,929	360,450		7,129,869		194,190
Financial liabilities
Deposits	$	5,612,880	4,153,782		1,486,996		—
FHLB advances	967,382		—		986,292		—
Repurchase agreements and other borrowed funds	322,779		—		322,779		—
Subordinated debentures	125,526		—		72,554		—
Accrued interest payable	3,568		3,568		—		—
Interest rate swaps	2,004		—		2,004		—
Total financial liabilities	$	7,034,139	4,157,350		2,870,625		—
			Fair Value Measurements
			At the End of the Reporting Period Using
(Dollars in thousands)	Carrying Amount December 31, 2012		Quoted Prices		Significant		Significant
			in Active  Markets		Other		Unobservable
			for Identical		Observable		Inputs
			Assets		Inputs		(Level 3)
			(Level 1)		(Level 2)
Financial assets
Cash and cash equivalents	$	187,040	187,040		—		—
Investment securities, available-for-sale	3,683,005		—		3,683,005		—
Loans held for sale	145,501		145,501		—		—
Loans receivable, net of ALLL	3,266,571		—		3,184,987		186,201
Accrued interest receivable	37,770		37,770		—		—
Non-marketable equity securities	48,812		—		48,812		—
Total financial assets	$	7,368,699	370,311		6,916,804		186,201
Financial liabilities
Deposits	$	5,364,461	3,585,126		1,789,134		—
FHLB advances	997,013		—		1,027,101		—
Repurchase agreements and other borrowed funds	299,540		—		299,540		—
Subordinated debentures	125,418		—		70,895		—
Accrued interest payable	4,675		4,675		—		—
Interest rate swaps	16,832		—		16,832		—
Total financial liabilities	$	6,807,939	3,589,801		3,203,502		—

Mergers_and_Acquisitions

Mergers and Acquisitions	9 Months Ended
	Sep. 30, 2013
Business Combinations [Abstract]	'
Mergers and Acquisitions	'
	Note 9. Mergers and Acquisitions
	On May 31, 2013, the Company acquired 100 percent of the outstanding common stock of Wheatland and its wholly-owned subsidiary, First State Bank, a community bank based in Wheatland, Wyoming. First State Bank provides community banking services to individuals and businesses from banking offices in Wheatland, Torrington and Guernsey, Wyoming. As a result of the acquisition, the Company has increased its presence in the State of Wyoming and will further diversify its loan, customer and deposit base with First State Bank’s strong commitment to agriculture. First State Bank operates as a division of the Bank under the name “First State Bank, division of Glacier Bank.” The Wheatland acquisition was valued at $39,315,000 and resulted in the Company issuing 1,455,256 shares of its common stock and $11,025,000 in cash in exchange for all of Wheatland’s outstanding common stock shares. The fair value of the Company’s common stock shares issued was determined on the basis of the closing market price of the Company’s common stock shares on the May 31, 2013 acquisition date.
	On July 31, 2013, the Company acquired 100 percent of the outstanding common stock of NCBI and its wholly-owned subsidiary, North Cascades National Bank, a community bank based in Chelan, Washington. North Cascades National Bank provides community banking services to individuals and businesses in central Washington, with banking offices located in Chelan, Wenatchee, East Wenatchee, Omak, Brewster, Twisp, Okanogan, Grand Coulee and Waterville, Washington. The acquisition expands the Company’s market into central Washington and further diversifies the Company’s loan, customer and deposit base due to the region’s solid economic base of agriculture, fruit processing and tourism. North Cascades National Bank operates as a division of the Bank under the name “North Cascades Bank, division of Glacier Bank.” The NCBI acquisition was valued at $30,576,000 and resulted in the Company issuing 687,876 shares of its common stock and $13,833,000 in cash in exchange for all of NCBI's outstanding common stock shares. The fair value of the Company's common stock shares issued was determined on the basis of the closing market price of the Company's common stock shares on the July 31, 2013 acquisition date.
	The assets and liabilities of Wheatland and NCBI were recorded on the Company’s consolidated statements of financial condition at their estimated fair values as of the May 31, 2013 and July 31, 2013 acquisition dates, respectively, and their results of operations have been included in the Company’s consolidated statements of operations since those dates. The excess of the fair value of consideration transferred over total identifiable net assets was recorded as goodwill. The goodwill arising from the acquisitions consists largely of the synergies and economies of scale expected from combining the operations of the Company, Wheatland and NCBI. None of the goodwill is deductible for income tax purposes as both acquisitions were accounted for as tax-free exchanges. The following table discloses the calculation of the fair value of consideration transferred, the total identifiable net assets acquired and the resulting goodwill relating to the Wheatland and NCBI acquisitions:
		Wheatland		NCBI
	(Dollars in thousands)	May 31,		July 31,	Total
		2013		2013
	Fair value of consideration transferred
	Fair value of Company shares issued, net of equity issuance costs	$	28,290	16,743	45,033
	Cash consideration for outstanding shares	11,025		13,833	24,858
	Total fair value of consideration transferred	39,315		30,576	69,891
	Recognized amounts of identifiable assets acquired and liabilities assumed
	Identifiable assets acquired
	Cash and cash equivalents	23,148		27,865	51,013
	Investment securities, available-for-sale	75,643		48,058	123,701
	Loans receivable	171,199		215,986	387,185
	Core deposit intangible	2,079		3,660	5,739
	Accrued income and other assets	15,063		24,262	39,325
	Total identifiable assets acquired	287,132		319,831	606,963
	Liabilities assumed
	Deposits	255,197		294,980	550,177
	Federal Home Loan Bank advances and other borrowed funds	5,467		—	5,467
	Accrued expenses and other liabilities	562		4,472	5,034
	Total liabilities assumed	261,226		299,452	560,678
	Total identifiable net assets	25,906		20,379	46,285
	Goodwill recognized	$	13,409	10,197	23,606
	The fair value of the Wheatland and NCBI assets acquired includes loans with fair values of $171,199,000 and $215,986,000, respectively. The gross principal and contractual interest due under the Wheatland and NCBI contracts is $176,698,000 and $223,949,000, respectively, all of which is expected to be collectible.
	The Company incurred $594,000 and $478,000, respectively, of Wheatland and NCBI third-party acquisition-related costs during the nine month period ended September 30, 2013. The expenses are included in other expense in the Company's consolidated statements of operations.
	Total income consisting of net interest income and non-interest income of the acquired operations of Wheatland was approximately $4,605,000 and net income was approximately $1,338,000 from May 31, 2013 to September 30, 2013. Total income consisting of net interest income and non-interest income of the acquired operations of NCBI was approximately $2,662,000 and net income was approximately $510,000 from July 31, 2013 to September 30, 2013. The following unaudited pro forma summary presents consolidated information of the Company as if the Wheatland and NCBI acquisitions had occurred on January 1, 2012:
		Three Months ended			Nine Months ended
	(Dollars in thousands)	September 30,		September 30,	September 30,	September 30,
		2013		2012	2013	2012
	Net interest income and non-interest income	$	86,940	77,095	249,224	251,525
	Net income	24,756		20,126	69,846	58,525

Nature_of_Operations_and_Summa1

Nature of Operations and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
General	'
	General
	Glacier Bancorp, Inc. (“Company”) is a Montana corporation headquartered in Kalispell, Montana. The Company provides a full range of banking services to individual and corporate customers in Montana, Idaho, Wyoming, Colorado, Utah and Washington through thirteen divisions of its wholly-owned bank subsidiary, Glacier Bank (“Bank”). The Company offers a wide range of banking products and services, including transaction and savings deposits, real estate, commercial, agriculture and consumer loans, mortgage origination services, and retail brokerage services. The Company serves individuals, small to medium-sized businesses, community organizations and public entities.
	In the opinion of management, the accompanying unaudited condensed consolidated financial statements contain all adjustments (consisting of normal recurring adjustments) necessary for a fair presentation of the Company’s financial condition as of September 30, 2013, the results of operations and comprehensive income for the three and nine month periods ended September 30, 2013 and 2012, and changes in stockholders’ equity and cash flows for the nine month periods ended September 30, 2013 and 2012. The condensed consolidated statement of financial condition of the Company as of December 31, 2012 has been derived from the audited consolidated statements of the Company as of that date.
	The accompanying unaudited condensed consolidated financial statements do not include all of the information and footnotes required by accounting principles generally accepted in the United States of America (“GAAP”) for complete financial statements. These unaudited condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2012. Operating results for the nine months ended September 30, 2013 are not necessarily indicative of the results anticipated for the year ending December 31, 2013.
	The Company is a defendant in legal proceedings arising in the normal course of business. In the opinion of management, the disposition of pending litigation will not have a material affect on the Company’s consolidated financial position, results of operations or liquidity.
	Material estimates that are particularly susceptible to significant change include the determination of the allowance for loan and lease losses (“ALLL” or “allowance”) and the valuations related to investments and real estate acquired in connection with foreclosures or in satisfaction of loans. For the determination of the ALLL and real estate valuation estimates, management obtains independent appraisals (new or updated) for significant items. Estimates relating to investment valuations are obtained from independent third parties.
Principles of Consolidation	'
	Principles of Consolidation
	The consolidated financial statements of the Company include the parent holding company and the Bank. The Bank consists of thirteen bank divisions, a treasury division and an information technology division. Each of the bank divisions operate under separate names, management teams and directors. The Company considers the Bank to be its sole operating segment as the Bank 1) engages in similar bank business activity from which it earns revenues and incurs expenses, 2) the operating results of the Bank are regularly reviewed by the Chief Executive Officer (i.e., the chief operating decision maker) who makes decisions about resources to be allocated to the Bank, and 3) financial information is available for the Bank. All significant inter-company transactions have been eliminated in consolidation.
	On May 31, 2013, the Company completed its acquisition of Wheatland Bankshares, Inc. (“Wheatland”) and its wholly-owned subsidiary, First State Bank, a community bank based in Wheatland, Wyoming. On July 31, 2013, the Company completed its acquisition of North Cascades Bancshares, Inc. (“NCBI”) and its wholly-owned subsidiary, North Cascades National Bank, a community bank based in Chelan, Washington. Both transactions were accounted for using the acquisition method, and their results of operations have been included in the Company’s consolidated financial statements as of the acquisition dates.
	The Company formed GBCI Other Real Estate (“GORE”) to isolate certain bank foreclosed properties for legal protection and administrative purposes and the remaining properties are currently held for sale. GORE is included in the Bank operating segment due to its insignificant activity.
	The Company owns the following trust subsidiaries, each of which issued trust preferred securities as Tier 1 capital instruments: Glacier Capital Trust II, Glacier Capital Trust III, Glacier Capital Trust IV, Citizens (ID) Statutory Trust I, Bank of the San Juans Bancorporation Trust I, First Company Statutory Trust 2001 and First Company Statutory Trust 2003. The trust subsidiaries are not included in the Company’s consolidated financial statements.
Variable Interest Entities	'
	Variable Interest Entities
	The Company has equity investments in Certified Development Entities (“CDE”) which have received allocations of New Markets Tax Credits (“NMTC”). The Company also has equity investments in Low-Income Housing Tax Credit (“LIHTC”) partnerships. The CDEs and the LIHTC partnerships are variable interest entities (“VIE”).
	The following table summarizes the carrying amounts of the VIE’s assets and liabilities included in the Company’s consolidated financial statements at September 30, 2013 and December 31, 2012:
		30-Sep-13			31-Dec-12
	(Dollars in thousands)	CDE (NMTC)		LIHTC	CDE (NMTC)	LIHTC
	Assets
	Loans receivable	$	35,956	—	35,480	—
	Premises and equipment, net	—		13,641	—	16,066
	Accrued interest receivable	113		—	117	—
	Other assets	903		153	1,114	143
	Total assets	$	36,972	13,794	36,711	16,209
	Liabilities
	Other borrowed funds	$	4,555	1,723	4,555	3,639
	Accrued interest payable	4		5	4	6
	Other liabilities	92		203	182	136
	Total liabilities	$	4,651	1,931	4,741	3,781
	Amounts presented in the table above are adjusted for intercompany eliminations. All assets presented can be used only to settle obligations of the consolidated VIEs and all liabilities presented consist of liabilities for which creditors and other beneficial interest holders therein have no recourse to the general credit of the Company.
Loans Receivable	'
	Loans Receivable
	Loans that are intended to be held-to-maturity are reported at the unpaid principal balance less net charge-offs and adjusted for deferred fees and costs on originated loans and unamortized premiums or discounts on acquired loans. Fees and costs on originated loans and premiums or discounts on acquired loans are deferred and subsequently amortized or accreted as a yield adjustment over the expected life of the loan utilizing the interest method. The objective of the interest method is to calculate periodic interest income at a constant effective yield. When a loan is paid off prior to maturity, the remaining fees and costs on originated loans and premiums or discounts on acquired loans are immediately recognized into interest income.
	The Company’s loan segments, which are based on the purpose of the loan, include residential real estate, commercial, and consumer loans. The Company’s loan classes, a further disaggregation of segments, include residential real estate loans (residential real estate segment), commercial real estate and other commercial loans (commercial segment), and home equity and other consumer loans (consumer segment).
	Loans that are thirty days or more past due based on payments received and applied to the loan are considered delinquent. Loans are designated non-accrual and the accrual of interest is discontinued when the collection of the contractual principal or interest is unlikely. A loan is typically placed on non-accrual when principal or interest is due and has remained unpaid for ninety days or more. When a loan is placed on non-accrual status, interest previously accrued but not collected is reversed against current period interest income. Subsequent payments are applied to the outstanding principal balance if doubt remains as to the ultimate collectability of the loan. Interest accruals are not resumed on partially charged-off impaired loans. For other loans on nonaccrual, interest accruals are resumed on such loans only when they are brought fully current with respect to interest and principal and when, in the judgment of management, the loans are estimated to be fully collectible as to both principal and interest.
	The Company considers impaired loans to be the primary credit quality indicator for monitoring the credit quality of the loan portfolio. Loans are designated impaired when, based upon current information and events, it is probable that the Company will be unable to collect the scheduled payments of principal or interest when due according to the contractual terms of the loan agreement and therefore, the Company has serious doubts as to the ability of such borrowers to fulfill the contractual obligation. Impaired loans include non-performing loans (i.e., non-accrual loans and accruing loans ninety days or more past due) and accruing loans under ninety days past due where it is probable payments will not be received according to the loan agreement (e.g., troubled debt restructuring). Interest income on accruing impaired loans is recognized using the interest method. The Company measures impairment on a loan-by-loan basis in the same manner for each class within the loan portfolio. An insignificant delay or shortfall in the amounts of payments would not cause a loan or lease to be considered impaired. The Company determines the significance of payment delays and shortfalls on a case-by-case basis, taking into consideration all of the facts and circumstances surrounding the loan and the borrower, including the length and reasons for the delay, the borrower’s prior payment record, and the amount of the shortfall in relation to the principal and interest due.
	A restructured loan is considered a troubled debt restructuring (“TDR”) if the creditor, for economic or legal reasons related to the debtor’s financial difficulties, grants a concession to the debtor that it would not otherwise consider. A TDR loan is considered an impaired loan and a specific valuation allowance is established when the fair value of the collateral-dependent loan or present value of the loan’s expected future cash flows (discounted at the loan’s effective interest rate based on the original contractual rate) is lower than the carrying value of the impaired loan. The Company made the following types of loan modifications, some of which were considered a TDR:
	•	Reduction of the stated interest rate for the remaining term of the debt;
	•	Extension of the maturity date(s) at a stated rate of interest lower than the current market rate for newly originated debt having similar risk characteristics; and
	•	Reduction of the face amount of the debt as stated in the debt agreements.
	The Company recognizes that while borrowers may experience deterioration in their financial condition, many continue to be creditworthy customers who have the willingness and capacity for debt repayment. In determining whether non-restructured or unimpaired loans issued to a single or related party group of borrowers should continue to accrue interest when the borrower has other loans that are impaired or are TDRs, the Company on a quarterly or more frequent basis performs an updated and comprehensive assessment of the willingness and capacity of the borrowers to timely and ultimately repay their total debt obligations, including contingent obligations. Such analysis takes into account current financial information about the borrowers and financially responsible guarantors, if any, including for example:
	•	analysis of global, i.e., aggregate debt service for total debt obligations;
	•	assessment of the value and security protection of collateral pledged using current market conditions and alternative market assumptions across a variety of potential future situations; and
	•	loan structures and related covenants.
	For additional information relating to loans, see Note 3.
Allowance for Loan and Lease Losses	'
	Allowance for Loan and Lease Losses
	Based upon management’s analysis of the Company’s loan portfolio, the balance of the ALLL is an estimate of probable credit losses known and inherent within the Bank’s loan portfolio as of the date of the consolidated financial statements. The ALLL is analyzed at the loan class level and is maintained within a range of estimated losses. Determining the adequacy of the ALLL involves a high degree of judgment and is inevitably imprecise as the risk of loss is difficult to quantify. The determination of the ALLL and the related provision for loan losses is a critical accounting estimate that involves management’s judgments about all known relevant internal and external environmental factors that affect loan losses. The balance of the ALLL is highly dependent upon management’s evaluations of borrowers’ current and prospective performance, appraisals and other variables affecting the quality of the loan portfolio. Individually significant loans and major lending areas are reviewed periodically to determine potential problems at an early date. Changes in management’s estimates and assumptions are reasonably possible and may have a material impact upon the Company’s consolidated financial statements, results of operations or capital.
	The ALLL consists of a specific valuation allowance component and a general valuation allowance component. The specific component relates to loans that are determined to be impaired and individually evaluated for impairment. The Company measures impairment on a loan-by-loan basis based on the present value of expected future cash flows discounted at the loan’s effective interest rate, except when it is determined that repayment of the loan is expected to be provided solely by the underlying collateral. For impairment based on expected future cash flows, the Company considers all information available as of a measurement date, including past events, current conditions, potential prepayments, and estimated cost to sell when such costs are expected to reduce the cash flows available to repay or otherwise satisfy the loan. For alternative ranges of cash flows, the likelihood of the possible outcomes is considered in determining the best estimate of expected future cash flows. The effective interest rate for a loan restructured in a TDR is based on the original contractual rate. For collateral-dependent loans and real estate loans for which foreclosure or a deed-in-lieu of foreclosure is probable, impairment is measured by the fair value of the collateral, less estimated cost to sell. The fair value of the collateral is determined primarily based upon appraisal or evaluation of the underlying real property value.
	The general valuation allowance component relates to probable credit losses inherent in the balance of the loan portfolio based on historical loss experience, adjusted for changes in trends and conditions of qualitative or environmental factors. The historical loss experience is based on the previous twelve quarters loss experience by loan class adjusted for risk characteristics in the existing loan portfolio. The same trends and conditions are evaluated for each class within the loan portfolio; however, the risk characteristics are weighted separately at the individual class level based on the Company’s judgment and experience.
	The changes in trends and conditions of certain items include the following:
	•	Changes in lending policies and procedures, including changes in underwriting standards and collection, charge-off, and recovery practices not considered elsewhere in estimating credit losses;
	•	Changes in international, national, regional, and local economic and business conditions and developments that affect the collectability of the portfolio, including the condition of various market segments;
	•	Changes in the nature and volume of the portfolio and in the terms of loans;
	•	Changes in experience, ability, and depth of lending management and other relevant staff;
	•	Changes in the volume and severity of past due and nonaccrual loans;
	•	Changes in the quality of the Company’s loan review system;
	•	Changes in the value of underlying collateral for collateral-dependent loans;
	•	The existence and effect of any concentrations of credit, and changes in the level of such concentrations; and
	•	The effect of other external factors such as competition and legal and regulatory requirements on the level of estimated credit losses in the Company’s existing portfolio.
	The ALLL is increased by provisions for loan losses which are charged to expense. The portions of loan balances determined by management to be uncollectible are charged-off as a reduction of the ALLL and recoveries of amounts previously charged-off are credited as an increase to the ALLL. The Company’s charge-off policy is consistent with bank regulatory standards. Consumer loans generally are charged off when the loan becomes over 120 days delinquent. Real estate acquired as a result of foreclosure or by deed-in-lieu of foreclosure is classified as real estate owned until such time as it is sold.
	At acquisition date, the assets and liabilities of acquired banks are recorded at their estimated fair values which results in no ALLL carried over from acquired banks. Subsequent to acquisition, an allowance will be recorded on the acquired loan portfolios for further credit deterioration, if any.
Impact of Recent Authoritative Accounting Guidance	'
	Impact of Recent Authoritative Accounting Guidance
	The Accounting Standards Codification™ (“ASC”) is the Financial Accounting Standards Board’s (“FASB”) officially recognized source of authoritative GAAP applicable to all public and non-public non-governmental entities. Rules and interpretive releases of the Securities and Exchange Commission (“SEC”) under the authority of the federal securities laws are also sources of authoritative GAAP for the Company as an SEC registrant. All other accounting literature is non-authoritative.
	In June 2011, FASB amended FASB ASC Topic 220, Comprehensive Income. The amendment provides an entity the option to present the total of comprehensive income, the components of net income, and the components of other comprehensive income either in a single continuous statement or in two separate but consecutive statements. Accounting Standards Update (“ASU”) No. 2011-12, Comprehensive Income (Topic 220) deferred the specific requirement of the amendment to present items that are reclassified from accumulated other comprehensive income to net income separately with their respective components of net income and other comprehensive income. The amendments were effective retrospectively during interim and annual periods beginning after December 15, 2011. ASU No. 2013-2, Comprehensive Income (Topic 220) reversed the deferment of ASU 2011-12 and will be effective prospectively for reporting periods beginning after December 15, 2012 and early adoption is permitted. The Company early adopted ASU No. 2013-2 as of December 31, 2012. The Company has evaluated the impact of the adoption of these amendments and determined there was not a material effect on the Company’s financial position or results of operations.

Nature_of_Operations_and_Summa2

Nature of Operations and Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Summary of the carrying amounts of variable interest entities' assets and liabilities included in consolidated financial statements	'
		30-Sep-13			31-Dec-12
	(Dollars in thousands)	CDE (NMTC)		LIHTC	CDE (NMTC)	LIHTC
	Assets
	Loans receivable	$	35,956	—	35,480	—
	Premises and equipment, net	—		13,641	—	16,066
	Accrued interest receivable	113		—	117	—
	Other assets	903		153	1,114	143
	Total assets	$	36,972	13,794	36,711	16,209
	Liabilities
	Other borrowed funds	$	4,555	1,723	4,555	3,639
	Accrued interest payable	4		5	4	6
	Other liabilities	92		203	182	136
	Total liabilities	$	4,651	1,931	4,741	3,781

Investment_Securities_Availabl1

Investment Securities, Available-for-Sale (Tables)	9 Months Ended
	Sep. 30, 2013
Investments, Debt and Equity Securities [Abstract]	'
Comparison of amortized cost and estimated fair value of investment securities designated as available-for-sale	'
		30-Sep-13
		Weighted			Amortized			Gross Unrealized				Fair
	(Dollars in thousands)	Yield			Cost			Gains		Losses		Value
	U.S. government sponsored enterprises
	Maturing after one year through five years	2.29	%		$	11,278		240		—		11,518
	Maturing after five years through ten years	1.82	%		38			—		—		38
		2.29	%		11,316			240		—		11,556
	State and local governments
	Maturing within one year	2.18	%		6,059			52		—		6,111
	Maturing after one year through five years	2.1	%		162,569			3,096		(431	)	165,234
	Maturing after five years through ten years	3.17	%		57,892			1,122		(832	)	58,182
	Maturing after ten years	4.46	%		1,104,890			28,571		(21,604	)	1,111,857
		4.1	%		1,331,410			32,841		(22,867	)	1,341,384
	Corporate bonds
	Maturing within one year	2.1	%		73,064			736		—		73,800
	Maturing after one year through five years	2.1	%		358,034			2,890		(2,852	)	358,072
	Maturing after five years through ten years	2.22	%		11,058			—		(85	)	10,973
		2.1	%		442,156			3,626		(2,937	)	442,845
	Residential mortgage-backed securities	2.44	%		1,515,728			15,357		(7,917	)	1,523,168
	Total investment securities	3.06	%		$	3,300,610		52,064		(33,721	)	3,318,953
		31-Dec-12
		Weighted			Amortized			Gross Unrealized				Fair
	(Dollars in thousands)	Yield			Cost			Gains		Losses		Value
	U.S. government and federal agency
	Maturing within one year	1.62	%		$	201		1		—		202
	U.S. government sponsored enterprises
	Maturing after one year through five years	2.3	%		17,064			371		—		17,435
	Maturing after five years through ten years	2.03	%		44			1		—		45
		2.29	%		17,108			372		—		17,480
	State and local governments
	Maturing within one year	2.01	%		4,288			28		(2	)	4,314
	Maturing after one year through five years	2.11	%		149,497			4,142		(142	)	153,497
	Maturing after five years through ten years	2.95	%		38,346			1,102		(99	)	39,349
	Maturing after ten years	4.7	%		935,897			82,823		(1,362	)	1,017,358
		4.29	%		1,128,028			88,095		(1,605	)	1,214,518
	Corporate bonds
	Maturing within one year	1.73	%		18,412			51		—		18,463
	Maturing after one year through five years	2.22	%		250,027			4,018		(238	)	253,807
	Maturing after five years through ten years	2.23	%		16,144			381		—		16,525
		2.19	%		284,583			4,450		(238	)	288,795
	Collateralized debt obligations
	Maturing after ten years	8.03	%		1,708			—		—		1,708
	Residential mortgage-backed securities	1.95	%		2,156,049			8,860		(4,607	)	2,160,302
	Total investment securities	2.71	%		$	3,587,677		101,778		(6,450	)	3,683,005
Gain or loss on sale of Investments	'
		Three Months ended						Nine Months ended
	(Dollars in thousands)	September 30,				September 30,		September 30,		September 30,
		2013				2012		2013		2012
	Gross proceeds	$	102,483			—		181,971		—
	Less amortized cost	(102,886		)		—		(182,270	)	—
	Net loss on sale of investments	$	(403	)		—		(299	)	—
	Gross gain on sale of investments	$	3,467			—		3,723		—
	Gross loss on sale of investments	(3,870		)		—		(4,022	)	—
	Net loss on sale of investments	$	(403	)		—		(299	)	—
Summary of investments with an unrealized loss position	'
		30-Sep-13
		Less than 12 Months						12 Months or More				Total
	(Dollars in thousands)	Fair				Unrealized		Fair		Unrealized		Fair	Unrealized
		Value				Loss		Value		Loss		Value	Loss
	State and local governments	$	405,834			(21,121	)	22,373		(1,746	)	428,207	(22,867	)
	Corporate bonds	189,130				(2,937	)	—		—		189,130	(2,937	)
	Residential mortgage-backed securities	446,642				(7,917	)	—		—		446,642	(7,917	)
	Total temporarily impaired securities	$	1,041,606			(31,975	)	22,373		(1,746	)	1,063,979	(33,721	)
		31-Dec-12
		Less than 12 Months						12 Months or More				Total
	(Dollars in thousands)	Fair				Unrealized		Fair		Unrealized		Fair	Unrealized
		Value				Loss		Value		Loss		Value	Loss
	State and local governments	$	102,896			(1,531	)	4,533		(74	)	107,429	(1,605	)
	Corporate bonds	41,856				(238	)	—		—		41,856	(238	)
	Residential mortgage-backed securities	955,235				(4,041	)	62,905		(566	)	1,018,140	(4,607	)
	Total temporarily impaired securities	$	1,099,987			(5,810	)	67,438		(640	)	1,167,425	(6,450	)

Loans_Receivable_Net_Tables

Loans Receivable, Net (Tables)	9 Months Ended
	Sep. 30, 2013
Receivables [Abstract]	'
Summary of the activity in the ALLL on a portfolio class basis	'
		Three Months ended September 30, 2013
	(Dollars in thousands)	Total			Residential		Commercial		Other		Home		Other
					Real Estate		Real Estate		Commercial		Equity		Consumer
	Allowance for loan and lease losses
	Balance at beginning of period	$	130,883		14,797		73,885		24,116		9,626		8,459
	Provision for loan losses	1,907			950		381		385		125		66
	Charge-offs	(3,077		)	(42	)	(1,235	)	(1,065	)	(333	)	(402	)
	Recoveries	1,052			45		367		385		73		182
	Balance at end of period	$	130,765		15,750		73,398		23,821		9,491		8,305
		Three Months ended September 30, 2012
	(Dollars in thousands)	Total			Residential		Commercial		Other		Home		Other
					Real Estate		Real Estate		Commercial		Equity		Consumer
	Allowance for loan and lease losses
	Balance at beginning of period	$	137,459		18,139		79,098		20,570		10,904		8,748
	Provision for loan losses	2,700			209		(1,210	)	2,859		(555	)	1,397
	Charge-offs	(5,052		)	(1,172	)	(586	)	(1,441	)	(1,044	)	(809	)
	Recoveries	1,553			73		453		241		679		107
	Balance at end of period	$	136,660		17,249		77,755		22,229		9,984		9,443
		Nine Months ended September 30, 2013
	(Dollars in thousands)	Total			Residential		Commercial		Other		Home		Other
					Real Estate		Real Estate		Commercial		Equity		Consumer
	Allowance for loan and lease losses
	Balance at beginning of period	$	130,854		15,482		74,398		21,567		10,659		8,748
	Provision for loan losses	5,085			464		(51	)	3,964		566		142
	Charge-offs	(8,962		)	(391	)	(2,538	)	(2,817	)	(1,962	)	(1,254	)
	Recoveries	3,788			195		1,589		1,107		228		669
	Balance at end of period	$	130,765		15,750		73,398		23,821		9,491		8,305
		Nine Months ended September 30, 2012
	(Dollars in thousands)	Total			Residential		Commercial		Other		Home		Other
					Real Estate		Real Estate		Commercial		Equity		Consumer
	Allowance for loan and lease losses
	Balance at beginning of period	$	137,516		17,227		76,920		20,833		13,616		8,920
	Provision for loan losses	19,250			2,294		11,800		4,163		(1,025	)	2,018
	Charge-offs	(24,789		)	(2,492	)	(13,120	)	(3,797	)	(3,402	)	(1,978	)
	Recoveries	4,683			220		2,155		1,030		795		483
	Balance at end of period	$	136,660		17,249		77,755		22,229		9,984		9,443
Summary of the ALLL and loans receivable on a portfolio class basis	'
		30-Sep-13
	(Dollars in thousands)	Total			Residential		Commercial		Other		Home		Other
					Real Estate		Real Estate		Commercial		Equity		Consumer
	Allowance for loan and lease losses
	Individually evaluated for impairment	$	12,728		1,088		6,662		3,810		109		1,059
	Collectively evaluated for impairment	118,037			14,662		66,736		20,011		9,382		7,246
	Total allowance for loan and lease losses	$	130,765		15,750		73,398		23,821		9,491		8,305
	Loans receivable
	Individually evaluated for impairment	$	206,918		27,104		125,566		38,390		10,091		5,767
	Collectively evaluated for impairment	3,794,181			556,713		1,868,492		795,839		363,421		209,716
	Total loans receivable	$	4,001,099		583,817		1,994,058		834,229		373,512		215,483
		31-Dec-12
	(Dollars in thousands)	Total			Residential		Commercial		Other		Home		Other
					Real Estate		Real Estate		Commercial		Equity		Consumer
	Allowance for loan and lease losses
	Individually evaluated for impairment	$	15,534		1,680		7,716		3,859		870		1,409
	Collectively evaluated for impairment	115,320			13,802		66,682		17,708		9,789		7,339
	Total allowance for loan and lease losses	$	130,854		15,482		74,398		21,567		10,659		8,748
	Loans receivable
	Individually evaluated for impairment	$	201,735		25,862		125,282		33,593		11,074		5,924
	Collectively evaluated for impairment	3,195,690			490,605		1,530,226		589,804		392,851		192,204
	Total loans receivable	$	3,397,425		516,467		1,655,508		623,397		403,925		198,128
Summary of impaired loans by portfolio class of loans	'
		At or for the Three or Nine Months ended September 30, 2013
	(Dollars in thousands)	Total			Residential		Commercial		Other		Home		Other
					Real Estate		Real Estate		Commercial		Equity		Consumer
	Loans with a specific valuation allowance
	Recorded balance	$	62,614		7,887		28,194		22,368		673		3,492
	Unpaid principal balance	64,969			8,032		29,463		22,986		717		3,771
	Specific valuation allowance	12,728			1,088		6,662		3,810		109		1,059
	Average balance - three months	59,817			7,431		26,525		21,780		495		3,586
	Average balance - nine months	59,402			7,237		26,653		21,321		737		3,454
	Loans without a specific valuation allowance
	Recorded balance	$	144,304		19,217		97,372		16,022		9,418		2,275
	Unpaid principal balance	174,258			20,681		120,914		19,233		11,026		2,404
	Average balance - three months	139,928			18,481		95,175		15,768		8,766		1,738
	Average balance - nine months	139,368			18,420		95,857		14,011		9,017		2,063
	Totals
	Recorded balance	$	206,918		27,104		125,566		38,390		10,091		5,767
	Unpaid principal balance	239,227			28,713		150,377		42,219		11,743		6,175
	Specific valuation allowance	12,728			1,088		6,662		3,810		109		1,059
	Average balance - three months	199,745			25,912		121,700		37,548		9,261		5,324
	Average balance - nine months	198,770			25,657		122,510		35,332		9,754		5,517
		At or for the Year ended December 31, 2012
	(Dollars in thousands)	Total			Residential		Commercial		Other		Home		Other
					Real Estate		Real Estate		Commercial		Equity		Consumer
	Loans with a specific valuation allowance
	Recorded balance	$	62,759		7,334		29,595		21,205		1,354		3,271
	Unpaid principal balance	70,261			7,459		36,887		21,278		1,362		3,275
	Specific valuation allowance	15,534			1,680		7,716		3,859		870		1,409
	Average balance	76,656			12,797		36,164		22,665		1,390		3,640
	Loans without a specific valuation allowance
	Recorded balance	$	138,976		18,528		95,687		12,388		9,720		2,653
	Unpaid principal balance	149,412			19,613		102,798		14,318		9,965		2,718
	Average balance	162,505			16,034		111,554		19,733		11,993		3,191
	Totals
	Recorded balance	$	201,735		25,862		125,282		33,593		11,074		5,924
	Unpaid principal balance	219,673			27,072		139,685		35,596		11,327		5,993
	Specific valuation allowance	15,534			1,680		7,716		3,859		870		1,409
	Average balance	239,161			28,831		147,718		42,398		13,383		6,831
Loans receivable aging analysis on a portfolio class basis	'
		30-Sep-13
	(Dollars in thousands)	Total			Residential		Commercial		Other		Home		Other
					Real Estate		Real Estate		Commercial		Equity		Consumer
	Accruing loans 30-59 days past due	$	21,294		516		11,829		5,854		1,828		1,267
	Accruing loans 60-89 days past due	5,107			824		2,419		683		797		384
	Accruing loans 90 days or more past due	174			—		109		35		28		2
	Non-accrual loans	88,293			12,604		53,536		11,591		8,953		1,609
	Total past due and non-accrual loans	114,868			13,944		67,893		18,163		11,606		3,262
	Current loans receivable	3,886,231			569,873		1,926,165		816,066		361,906		212,221
	Total loans receivable	$	4,001,099		583,817		1,994,058		834,229		373,512		215,483
		December 31, 2012
	(Dollars in thousands)	Total			Residential		Commercial		Other		Home		Other
					Real Estate		Real Estate		Commercial		Equity		Consumer
	Accruing loans 30-59 days past due	$	17,454		3,897		7,424		2,020		2,872		1,241
	Accruing loans 60-89 days past due	9,643			1,870		3,745		645		2,980		403
	Accruing loans 90 days or more past due	1,479			451		594		197		188		49
	Non-accrual loans	96,933			14,237		55,687		13,200		11,241		2,568
	Total past due and non-accrual loans	125,509			20,455		67,450		16,062		17,281		4,261
	Current loans receivable	3,271,916			496,012		1,588,058		607,335		386,644		193,867
	Total loans receivable	$	3,397,425		516,467		1,655,508		623,397		403,925		198,128
Summary of troubled debt restructurings on a portfolio class basis	'
		Three Months ended September 30, 2013
	(Dollars in thousands)	Total			Residential		Commercial		Other		Home		Other
					Real Estate		Real Estate		Commercial		Equity		Consumer
	Troubled debt restructurings
	Number of loans	9			2		4		—		1		2
	Pre-modification recorded balance	$	2,926		284		2,481		—		57		104
	Post-modification recorded balance	$	3,141		499		2,481		—		57		104
	Troubled debt restructurings that subsequently defaulted
	Number of loans	2			—		—		2		—		—
	Recorded balance	$	363		—		—		363		—		—
		Three Months ended September 30, 2012
	(Dollars in thousands)	Total			Residential		Commercial		Other		Home		Other
					Real Estate		Real Estate		Commercial		Equity		Consumer
	Troubled debt restructurings
	Number of loans	46			1		21		19		2		3
	Pre-modification recorded balance	$	38,125		280		20,866		16,601		219		159
	Post-modification recorded balance	$	35,475		281		18,242		16,571		222		159
	Troubled debt restructurings that subsequently defaulted
	Number of loans	3			2		—		—		1		—
	Recorded balance	$	1,792		1,622		—		—		170		—
		Nine Months ended September 30, 2013
	(Dollars in thousands)	Total			Residential		Commercial		Other		Home		Other
					Real Estate		Real Estate		Commercial		Equity		Consumer
	Troubled debt restructurings
	Number of loans	50			9		17		17		2		5
	Pre-modification recorded balance	$	12,016		1,907		7,137		2,572		147		253
	Post-modification recorded balance	$	12,418		2,293		7,137		2,588		147		253
	Troubled debt restructurings that subsequently defaulted
	Number of loans	10			1		4		5		—		—
	Recorded balance	$	2,772		265		1,918		589		—		—
		Nine Months ended September 30, 2012
	(Dollars in thousands)	Total			Residential		Commercial		Other		Home		Other
					Real Estate		Real Estate		Commercial		Equity		Consumer
	Troubled debt restructurings
	Number of loans	149			9		61		60		9		10
	Pre-modification recorded balance	$	66,580		1,981		37,712		25,033		1,314		540
	Post-modification recorded balance	$	61,944		1,982		33,080		25,025		1,317		540
	Troubled debt restructurings that subsequently defaulted
	Number of loans	17			2		10		3		1		1
	Recorded balance	$	10,204		1,622		7,553		801		170		58

Goodwill_Tables

Goodwill (Tables)	9 Months Ended
	Sep. 30, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
Changes in the Carrying Value of Goodwill	'
		Three Months ended					Nine Months ended
	(Dollars in thousands)	September 30,			September 30,		September 30,	September 30,
		2013			2012		2013	2012
	Net carrying value at beginning of period	$	119,509		106,100		106,100	106,100
	Acquisitions	10,197			—		23,606	—
	Net carrying value at end of period	$	129,706		106,100		129,706	106,100
Net Carrying Value of Goodwill	'
	(Dollars in thousands)	September 30,			December 31,
		2013			2012
	Gross carrying value	$	169,865		146,259
	Accumulated impairment charge	(40,159		)	(40,159	)
	Net carrying value	$	129,706		106,100

Derivatives_and_Hedging_Activi1

Derivatives and Hedging Activities (Tables)	9 Months Ended
	Sep. 30, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Summary of interest rate swap derivative financial instruments	'
	(Dollars in thousands)	Forecasted				Variable	Fixed		Term 2
		Notional  Amount				Interest Rate 1	Interest Rate 1
	Interest rate swap	$	160,000			3 month LIBOR	3.378	%	Oct. 21, 2014 - Oct. 21, 2021
	Interest rate swap	100,000				3 month LIBOR	2.498	%	Nov 30, 2015 - Nov. 30, 2022
	__________
	1 The Company pays the fixed interest rate and the counterparties pay the Company the variable interest rate.
	2 No cash will be exchanged prior to the term.
Fair value of interest rate swap derivative financial instruments	'
				Fair Value
	(Dollars in thousands)	Balance Sheet		September 30,			December 31,
		Location		2013			2012
	Interest rate swaps	Other liabilities		$	2,004		16,832

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Tables)	9 Months Ended
	Sep. 30, 2013
Equity [Abstract]	'
Components of accumulated other comprehensive income	'
	(Dollars in thousands)	September 30,			December 31,
		2013			2012
	Unrealized gains on available-for-sale securities	$	18,343		95,328
	Tax effect	(7,136		)	(37,083	)
	Net of tax amount	11,207			58,245
	Unrealized losses on derivatives used for cash flow hedges	(2,004		)	(16,832	)
	Tax effect	780			6,549
	Net of tax amount	(1,224		)	(10,283	)
	Total accumulated other comprehensive income	$	9,983		47,962

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Basic and diluted earnings per share	'
		Three Months ended			Nine Months ended
	(Dollars in thousands, except per share data)	September 30,		September 30,	September 30,	September 30,
		2013		2012	2013	2012
	Net income available to common stockholders, basic and diluted	$	25,628	19,444	69,098	54,758
	Average outstanding shares - basic	73,945,523		71,933,141	72,804,321	71,925,664
	Add: dilutive stock options and awards	76,348		40,844	65,154	97
	Average outstanding shares - diluted	74,021,871		71,973,985	72,869,475	71,925,761
	Basic earnings per share	$	0.35	0.27	0.95	0.76
	Diluted earnings per share	$	0.35	0.27	0.95	0.76

Fair_Value_of_Assets_and_Liabi1

Fair Value of Assets and Liabilities (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Fair value measurement of assets and liabilities measured at fair value on a recurring basis	'
				Fair Value Measurements
				At the End of the Reporting Period Using
	(Dollars in thousands)	Fair Value September 30, 2013		Quoted Prices		Significant		Significant
				in Active  Markets		Other		Unobservable
				for Identical		Observable		Inputs
				Assets		Inputs		(Level 3)
				(Level 1)		(Level 2)
	Investment securities, available-for-sale
	U.S. government sponsored enterprises	$	11,556	—		11,556		—
	State and local governments	1,341,384		—		1,341,384		—
	Corporate bonds	442,845		—		442,845		—
	Residential mortgage-backed securities	1,523,168		—		1,523,168		—
	Total assets measured at fair value on a recurring basis	$	3,318,953	—		3,318,953		—
	Interest rate swaps	$	2,004	—		2,004		—
	Total liabilities measured at fair value on a recurring basis	$	2,004	—		2,004		—
				Fair Value Measurements
				At the End of the Reporting Period Using
	(Dollars in thousands)	Fair Value December 31, 2012		Quoted Prices		Significant		Significant
				in Active  Markets		Other		Unobservable
				for Identical		Observable		Inputs
				Assets		Inputs		(Level 3)
				(Level 1)		(Level 2)
	Investment securities, available-for-sale
	U.S. government and federal agency	$	202	—		202		—
	U.S. government sponsored enterprises	17,480		—		17,480		—
	State and local governments	1,214,518		—		1,214,518		—
	Corporate bonds	288,795		—		288,795		—
	Collateralized debt obligations	1,708		—		1,708		—
	Residential mortgage-backed securities	2,160,302		—		2,160,302		—
	Total assets measured at fair value on a recurring basis	$	3,683,005	—		3,683,005		—
	Interest rate swaps	$	16,832	—		16,832		—
	Total liabilities measured at fair value on a recurring basis	$	16,832	—		16,832		—
Fair value measurement of assets measured at fair value on a non-recurring basis	'
				Fair Value Measurements
				At the End of the Reporting Period Using
	(Dollars in thousands)	Fair Value September 30, 2013		Quoted Prices		Significant		Significant
				in Active  Markets		Other		Unobservable
				for Identical		Observable		Inputs
				Assets		Inputs		(Level 3)
				(Level 1)		(Level 2)
	Other real estate owned	$	7,646	—		—		7,646
	Collateral-dependent impaired loans, net of ALLL	19,066		—		—		19,066
	Total assets measured at fair value on a non-recurring basis	$	26,712	—		—		26,712
				Fair Value Measurements
				At the End of the Reporting Period Using
	(Dollars in thousands)	Fair Value December 31, 2012		Quoted Prices		Significant		Significant
				in Active  Markets		Other		Unobservable
				for Identical		Observable		Inputs
				Assets		Inputs		(Level 3)
				(Level 1)		(Level 2)
	Other real estate owned	$	13,983	—		—		13,983
	Collateral-dependent impaired loans, net of ALLL	22,966		—		—		22,966
	Total assets measured at fair value on a non-recurring basis	$	36,949	—		—		36,949
Quantitative information about assets measured at fair value on a non-recurring basis for which Level 3 inputs were used	'
		Fair Value		Quantitative Information about Level 3 Fair Value Measurements
	(Dollars in thousands)	September 30,		Valuation Technique	Unobservable Input		Range (Weighted Average) 1
		2013
	Other real estate owned	$	6,828	Sales comparison approach	Selling costs		1.0% - 11.0% (7.0%)
					Adjustment to comparables		0.0% - 10.0% (0.0%)
		818		Combined approach	Selling costs		5.0% - 5.0% (5.0%)
					Adjustment to comparables		25.0% - 25.0% (25.0%)
		$	7,646
	Collateral-dependent impaired loans, net of ALLL	$	442	Cost approach	Selling costs		10.0% - 50.0% (19.2%)
		2,553		Income approach	Selling costs		8.0% - 8.0% (8.0%)
					Discount rate		8.3% - 8.3% (8.3%)
		13,700		Sales comparison approach	Selling costs		0.0% - 10.0% (8.0%)
					Discount rate		0.0% - 0.0% (0.0%)
					Adjustment to comparables		0.0% - 1.0% (0.0%)
		2,371		Combined approach	Selling costs		8.0% - 8.0% (8.0%)
					Adjustment to comparables		10.0% - 36.0% (22.5%)
		$	19,066
	__________
	1 The range for selling costs and adjustments to comparables indicate reductions to the fair value.
Carrying amounts and estimated fair values of financial instruments	'
				Fair Value Measurements
				At the End of the Reporting Period Using
	(Dollars in thousands)	Carrying Amount September 30, 2013		Quoted Prices		Significant		Significant
				in Active  Markets		Other		Unobservable
				for Identical		Observable		Inputs
				Assets		Inputs		(Level 3)
				(Level 1)		(Level 2)
	Financial assets
	Cash and cash equivalents	$	254,684	254,684		—		—
	Investment securities, available-for-sale	3,318,953		—		3,318,953		—
	Loans held for sale	61,505		61,505		—		—
	Loans receivable, net of ALLL	3,870,334		—		3,758,724		194,190
	Accrued interest receivable	44,261		44,261		—		—
	Non-marketable equity securities	52,192		—		52,192		—
	Total financial assets	$	7,601,929	360,450		7,129,869		194,190
	Financial liabilities
	Deposits	$	5,612,880	4,153,782		1,486,996		—
	FHLB advances	967,382		—		986,292		—
	Repurchase agreements and other borrowed funds	322,779		—		322,779		—
	Subordinated debentures	125,526		—		72,554		—
	Accrued interest payable	3,568		3,568		—		—
	Interest rate swaps	2,004		—		2,004		—
	Total financial liabilities	$	7,034,139	4,157,350		2,870,625		—
				Fair Value Measurements
				At the End of the Reporting Period Using
	(Dollars in thousands)	Carrying Amount December 31, 2012		Quoted Prices		Significant		Significant
				in Active  Markets		Other		Unobservable
				for Identical		Observable		Inputs
				Assets		Inputs		(Level 3)
				(Level 1)		(Level 2)
	Financial assets
	Cash and cash equivalents	$	187,040	187,040		—		—
	Investment securities, available-for-sale	3,683,005		—		3,683,005		—
	Loans held for sale	145,501		145,501		—		—
	Loans receivable, net of ALLL	3,266,571		—		3,184,987		186,201
	Accrued interest receivable	37,770		37,770		—		—
	Non-marketable equity securities	48,812		—		48,812		—
	Total financial assets	$	7,368,699	370,311		6,916,804		186,201
	Financial liabilities
	Deposits	$	5,364,461	3,585,126		1,789,134		—
	FHLB advances	997,013		—		1,027,101		—
	Repurchase agreements and other borrowed funds	299,540		—		299,540		—
	Subordinated debentures	125,418		—		70,895		—
	Accrued interest payable	4,675		4,675		—		—
	Interest rate swaps	16,832		—		16,832		—
	Total financial liabilities	$	6,807,939	3,589,801		3,203,502		—

Mergers_and_Acquisitions_Table

Mergers and Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2013
Business Combinations [Abstract]	'
Consideration transferred, identifiable net assets and resulting goodwill	'
		Wheatland		NCBI
	(Dollars in thousands)	May 31,		July 31,	Total
		2013		2013
	Fair value of consideration transferred
	Fair value of Company shares issued, net of equity issuance costs	$	28,290	16,743	45,033
	Cash consideration for outstanding shares	11,025		13,833	24,858
	Total fair value of consideration transferred	39,315		30,576	69,891
	Recognized amounts of identifiable assets acquired and liabilities assumed
	Identifiable assets acquired
	Cash and cash equivalents	23,148		27,865	51,013
	Investment securities, available-for-sale	75,643		48,058	123,701
	Loans receivable	171,199		215,986	387,185
	Core deposit intangible	2,079		3,660	5,739
	Accrued income and other assets	15,063		24,262	39,325
	Total identifiable assets acquired	287,132		319,831	606,963
	Liabilities assumed
	Deposits	255,197		294,980	550,177
	Federal Home Loan Bank advances and other borrowed funds	5,467		—	5,467
	Accrued expenses and other liabilities	562		4,472	5,034
	Total liabilities assumed	261,226		299,452	560,678
	Total identifiable net assets	25,906		20,379	46,285
	Goodwill recognized	$	13,409	10,197	23,606
Unaudited Pro Forma Summary of the Company as if the Acquisitions had Occurred at the Beginning of the Period	'
		Three Months ended			Nine Months ended
	(Dollars in thousands)	September 30,		September 30,	September 30,	September 30,
		2013		2012	2013	2012
	Net interest income and non-interest income	$	86,940	77,095	249,224	251,525
	Net income	24,756		20,126	69,846	58,525

VIE_Carrying_Amounts_Included_

VIE Carrying Amounts Included in Financial Statements (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
CDE (NMTC)	'	'
Carrying amounts of the entities assets and liabilities	'	'
Loans receivable	$35,956	$35,480
Premises and equipment, net	0	0
Accrued interest receivable	113	117
Other assets	903	1,114
Total assets	36,972	36,711
Other borrowed funds	4,555	4,555
Accrued interest payable	4	4
Other liabilities	92	182
Total liabilities	4,651	4,741
LIHTC	'	'
Carrying amounts of the entities assets and liabilities	'	'
Loans receivable	0	0
Premises and equipment, net	13,641	16,066
Accrued interest receivable	0	0
Other assets	153	143
Total assets	13,794	16,209
Other borrowed funds	1,723	3,639
Accrued interest payable	5	6
Other liabilities	203	136
Total liabilities	$1,931	$3,781

Nature_of_Operations_and_Summa3

Nature of Operations and Summary of Significant Accounting Policies (Details Textual)	9 Months Ended
	Sep. 30, 2013
Nature of Operations and Summary of Significant Accounting Policies	'
Number of Bank Divisions	13
Number of Operating Segments	1
Minimum Period Past Due to Consider Loan as Delinquent	'30 days
Minimum Period Past Due to Consider Loan as Non Accrual	'90 days
Minimum Number of Days Delinquent to Charge off Consumer Loans	'120 days

Amortized_Cost_and_Fair_Value_

Amortized Cost and Fair Value of Investment Securities (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Comparison of amortized cost and estimated fair value of investment securities, available-for-sale	'	'
Total investment securities, weighted yield	3.06%	2.71%
Total investment securities, amortized cost	$3,300,610	$3,587,677
Total investment securities, gross unrealized gains	52,064	101,778
Total investment securities, gross unrealized losses	-33,721	-6,450
Total investment securities, fair value	3,318,953	3,683,005
U.S. government and federal agency	'	'
Comparison of amortized cost and estimated fair value of investment securities, available-for-sale	'	'
Maturing within one year, weighted yield	'	1.62%
Maturing within one year, amortized cost	'	201
Maturing within one year, gross unrealized gains	'	1
Maturing within one year, gross unrealized losses	'	0
Maturing within one year, fair value	'	202
U.S. government sponsored enterprises	'	'
Comparison of amortized cost and estimated fair value of investment securities, available-for-sale	'	'
Maturing after one year through five years, weighted yield	2.29%	2.30%
Maturing after five years through ten years, weighted yield	1.82%	2.03%
Total investment securities, weighted yield	2.29%	2.29%
Maturing after one year through five years, amortized cost	11,278	17,064
Maturing after five years through ten years, amortized cost	38	44
Total investment securities, amortized cost	11,316	17,108
Maturing after one year through five years, gross unrealized gains	240	371
Maturing after five years through ten years, gross unrealized gains	0	1
Total investment securities, gross unrealized gains	240	372
Maturing after one year through five years, gross unrealized losses	0	0
Maturing after five years through ten years, gross unrealized losses	0	0
Total investment securities, gross unrealized losses	0	0
Maturing after one year through five years, fair value	11,518	17,435
Maturing after five years through ten years, fair value	38	45
Total investment securities, fair value	11,556	17,480
State and local governments	'	'
Comparison of amortized cost and estimated fair value of investment securities, available-for-sale	'	'
Maturing within one year, weighted yield	2.18%	2.01%
Maturing after one year through five years, weighted yield	2.10%	2.11%
Maturing after five years through ten years, weighted yield	3.17%	2.95%
Maturing after ten years, weighted yield	4.46%	4.70%
Total investment securities, weighted yield	4.10%	4.29%
Maturing within one year, amortized cost	6,059	4,288
Maturing after one year through five years, amortized cost	162,569	149,497
Maturing after five years through ten years, amortized cost	57,892	38,346
Maturing after ten years, amortized cost	1,104,890	935,897
Total investment securities, amortized cost	1,331,410	1,128,028
Maturing within one year, gross unrealized gains	52	28
Maturing after one year through five years, gross unrealized gains	3,096	4,142
Maturing after five years through ten years, gross unrealized gains	1,122	1,102
Maturing after ten years, gross unrealized gains	28,571	82,823
Total investment securities, gross unrealized gains	32,841	88,095
Maturing within one year, gross unrealized losses	0	-2
Maturing after one year through five years, gross unrealized losses	-431	-142
Maturing after five years through ten years, gross unrealized losses	-832	-99
Maturing after ten years, gross unrealized losses	-21,604	-1,362
Total investment securities, gross unrealized losses	-22,867	-1,605
Maturing within one year, fair value	6,111	4,314
Maturing after one year through five years, fair value	165,234	153,497
Maturing after five years through ten years, fair value	58,182	39,349
Maturing after ten years, fair value	1,111,857	1,017,358
Total investment securities, fair value	1,341,384	1,214,518
Corporate bonds	'	'
Comparison of amortized cost and estimated fair value of investment securities, available-for-sale	'	'
Maturing within one year, weighted yield	2.10%	1.73%
Maturing after one year through five years, weighted yield	2.10%	2.22%
Maturing after five years through ten years, weighted yield	2.22%	2.23%
Total investment securities, weighted yield	2.10%	2.19%
Maturing within one year, amortized cost	73,064	18,412
Maturing after one year through five years, amortized cost	358,034	250,027
Maturing after five years through ten years, amortized cost	11,058	16,144
Total investment securities, amortized cost	442,156	284,583
Maturing within one year, gross unrealized gains	736	51
Maturing after one year through five years, gross unrealized gains	2,890	4,018
Maturing after five years through ten years, gross unrealized gains	0	381
Total investment securities, gross unrealized gains	3,626	4,450
Maturing within one year, gross unrealized losses	0	0
Maturing after one year through five years, gross unrealized losses	-2,852	-238
Maturing after five years through ten years, gross unrealized losses	-85	0
Total investment securities, gross unrealized losses	-2,937	-238
Maturing within one year, fair value	73,800	18,463
Maturing after one year through five years, fair value	358,072	253,807
Maturing after five years through ten years, fair value	10,973	16,525
Total investment securities, fair value	442,845	288,795
Collateralized debt obligations	'	'
Comparison of amortized cost and estimated fair value of investment securities, available-for-sale	'	'
Maturing after ten years, weighted yield	'	8.03%
Maturing after ten years, amortized cost	'	1,708
Maturing after ten years, gross unrealized gains	'	0
Maturing after ten years, gross unrealized losses	'	0
Maturing after ten years, fair value	'	1,708
Residential mortgage-backed securities	'	'
Comparison of amortized cost and estimated fair value of investment securities, available-for-sale	'	'
Total investment securities, weighted yield	2.44%	1.95%
Total investment securities, amortized cost	1,515,728	2,156,049
Total investment securities, gross unrealized gains	15,357	8,860
Total investment securities, gross unrealized losses	-7,917	-4,607
Total investment securities, fair value	$1,523,168	$2,160,302

Gain_or_Loss_on_Sale_of_Invest

Gain or Loss on Sale of Investments (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Gain or loss on sale of investments	'	'	'	'
Gross proceeds	$102,483	$0	$181,971	$0
Less amortized cost	-102,886	0	-182,270	0
Net loss on sale of investments	-403	0	-299	0
Gross gain on sale of investments	3,467	0	3,723	0
Gross loss on sale of investments	($3,870)	$0	($4,022)	$0

Investment_with_an_Unrealized_

Investment with an Unrealized Loss Position (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value	'	'
Fair Value, Less than 12 Months	$1,041,606	$1,099,987
Fair Value, 12 Months or More	22,373	67,438
Fair Value, Total	1,063,979	1,167,425
Unrealized Loss	'	'
Unrealized Loss, Less than 12 Months	-31,975	-5,810
Unrealized Loss, 12 Months or More	-1,746	-640
Unrealized Loss, Total	-33,721	-6,450
State and local governments	'	'
Fair Value	'	'
Fair Value, Less than 12 Months	405,834	102,896
Fair Value, 12 Months or More	22,373	4,533
Fair Value, Total	428,207	107,429
Unrealized Loss	'	'
Unrealized Loss, Less than 12 Months	-21,121	-1,531
Unrealized Loss, 12 Months or More	-1,746	-74
Unrealized Loss, Total	-22,867	-1,605
Corporate bonds	'	'
Fair Value	'	'
Fair Value, Less than 12 Months	189,130	41,856
Fair Value, 12 Months or More	0	0
Fair Value, Total	189,130	41,856
Unrealized Loss	'	'
Unrealized Loss, Less than 12 Months	-2,937	-238
Unrealized Loss, 12 Months or More	0	0
Unrealized Loss, Total	-2,937	-238
Residential mortgage-backed securities	'	'
Fair Value	'	'
Fair Value, Less than 12 Months	446,642	955,235
Fair Value, 12 Months or More	0	62,905
Fair Value, Total	446,642	1,018,140
Unrealized Loss	'	'
Unrealized Loss, Less than 12 Months	-7,917	-4,041
Unrealized Loss, 12 Months or More	0	-566
Unrealized Loss, Total	($7,917)	($4,607)

Investment_Securities_Availabl2

Investment Securities, Available-for-Sale (Details Textual) (Residential mortgage-backed securities, USD $)	Sep. 30, 2013	Dec. 31, 2012
Residential mortgage-backed securities	'	'
Investment Securities, Available-for-Sale (Textual) [Abstract]	'	'
Non-guaranteed private label whole loan mortgage-backed securities	$3,214,000	$46,733,000

ALLL_Activity_Details

ALLL Activity (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Allowance for loan and lease losses	'	'	'	'
Balance at beginning of period	$130,883	$137,459	$130,854	$137,516
Provision for loan losses	1,907	2,700	5,085	19,250
Charge-offs	-3,077	-5,052	-8,962	-24,789
Recoveries	1,052	1,553	3,788	4,683
Balance at end of period	130,765	136,660	130,765	136,660
Residential Real Estate	'	'	'	'
Allowance for loan and lease losses	'	'	'	'
Balance at beginning of period	14,797	18,139	15,482	17,227
Provision for loan losses	950	209	464	2,294
Charge-offs	-42	-1,172	-391	-2,492
Recoveries	45	73	195	220
Balance at end of period	15,750	17,249	15,750	17,249
Commercial Real Estate	'	'	'	'
Allowance for loan and lease losses	'	'	'	'
Balance at beginning of period	73,885	79,098	74,398	76,920
Provision for loan losses	381	-1,210	-51	11,800
Charge-offs	-1,235	-586	-2,538	-13,120
Recoveries	367	453	1,589	2,155
Balance at end of period	73,398	77,755	73,398	77,755
Other Commercial	'	'	'	'
Allowance for loan and lease losses	'	'	'	'
Balance at beginning of period	24,116	20,570	21,567	20,833
Provision for loan losses	385	2,859	3,964	4,163
Charge-offs	-1,065	-1,441	-2,817	-3,797
Recoveries	385	241	1,107	1,030
Balance at end of period	23,821	22,229	23,821	22,229
Home Equity	'	'	'	'
Allowance for loan and lease losses	'	'	'	'
Balance at beginning of period	9,626	10,904	10,659	13,616
Provision for loan losses	125	-555	566	-1,025
Charge-offs	-333	-1,044	-1,962	-3,402
Recoveries	73	679	228	795
Balance at end of period	9,491	9,984	9,491	9,984
Other Consumer	'	'	'	'
Allowance for loan and lease losses	'	'	'	'
Balance at beginning of period	8,459	8,748	8,748	8,920
Provision for loan losses	66	1,397	142	2,018
Charge-offs	-402	-809	-1,254	-1,978
Recoveries	182	107	669	483
Balance at end of period	$8,305	$9,443	$8,305	$9,443

ALLL_and_Loans_Receivable_Summ

ALLL and Loans Receivable Summary (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Allowance for Loan and Lease Losses and Loans Receivable	'	'
Individually evaluated for impairment	$12,728	$15,534
Collectively evaluated for impairment	118,037	115,320
Total allowances for loan and lease losses	130,765	130,854
Individually evaluated for impairment	206,918	201,735
Collectively evaluated for impairment	3,794,181	3,195,690
Total loans receivable	4,001,099	3,397,425
Residential Real Estate	'	'
Allowance for Loan and Lease Losses and Loans Receivable	'	'
Individually evaluated for impairment	1,088	1,680
Collectively evaluated for impairment	14,662	13,802
Total allowances for loan and lease losses	15,750	15,482
Individually evaluated for impairment	27,104	25,862
Collectively evaluated for impairment	556,713	490,605
Total loans receivable	583,817	516,467
Commercial Real Estate	'	'
Allowance for Loan and Lease Losses and Loans Receivable	'	'
Individually evaluated for impairment	6,662	7,716
Collectively evaluated for impairment	66,736	66,682
Total allowances for loan and lease losses	73,398	74,398
Individually evaluated for impairment	125,566	125,282
Collectively evaluated for impairment	1,868,492	1,530,226
Total loans receivable	1,994,058	1,655,508
Other Commercial	'	'
Allowance for Loan and Lease Losses and Loans Receivable	'	'
Individually evaluated for impairment	3,810	3,859
Collectively evaluated for impairment	20,011	17,708
Total allowances for loan and lease losses	23,821	21,567
Individually evaluated for impairment	38,390	33,593
Collectively evaluated for impairment	795,839	589,804
Total loans receivable	834,229	623,397
Home Equity	'	'
Allowance for Loan and Lease Losses and Loans Receivable	'	'
Individually evaluated for impairment	109	870
Collectively evaluated for impairment	9,382	9,789
Total allowances for loan and lease losses	9,491	10,659
Individually evaluated for impairment	10,091	11,074
Collectively evaluated for impairment	363,421	392,851
Total loans receivable	373,512	403,925
Other Consumer	'	'
Allowance for Loan and Lease Losses and Loans Receivable	'	'
Individually evaluated for impairment	1,059	1,409
Collectively evaluated for impairment	7,246	7,339
Total allowances for loan and lease losses	8,305	8,748
Individually evaluated for impairment	5,767	5,924
Collectively evaluated for impairment	209,716	192,204
Total loans receivable	$215,483	$198,128

Impaired_Loans_Details

Impaired Loans (Details) (USD $)	3 Months Ended	9 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2013	Dec. 31, 2012
Summary of the impaired loans by portfolio class of loans	'	'	'
Loans with a specific valuation allowance, Recorded balance	$62,614	$62,614	$62,759
Loans with a specific valuation allowance, Unpaid principal balance	64,969	64,969	70,261
Loans with a specific valuation allowance, Specific valuation allowance	12,728	12,728	15,534
Loans with a specific valuation allowance, Average balance	59,817	59,402	76,656
Loans without a specific valuation allowance, Recorded balance	144,304	144,304	138,976
Loans without a specific valuation allowance, Unpaid principal balance	174,258	174,258	149,412
Loans without a specific valuation allowance, Average balance	139,928	139,368	162,505
Recorded balance	206,918	206,918	201,735
Unpaid principal balance	239,227	239,227	219,673
Specific valuation allowance	12,728	12,728	15,534
Average balance	199,745	198,770	239,161
Residential Real Estate	'	'	'
Summary of the impaired loans by portfolio class of loans	'	'	'
Loans with a specific valuation allowance, Recorded balance	7,887	7,887	7,334
Loans with a specific valuation allowance, Unpaid principal balance	8,032	8,032	7,459
Loans with a specific valuation allowance, Specific valuation allowance	1,088	1,088	1,680
Loans with a specific valuation allowance, Average balance	7,431	7,237	12,797
Loans without a specific valuation allowance, Recorded balance	19,217	19,217	18,528
Loans without a specific valuation allowance, Unpaid principal balance	20,681	20,681	19,613
Loans without a specific valuation allowance, Average balance	18,481	18,420	16,034
Recorded balance	27,104	27,104	25,862
Unpaid principal balance	28,713	28,713	27,072
Specific valuation allowance	1,088	1,088	1,680
Average balance	25,912	25,657	28,831
Commercial Real Estate	'	'	'
Summary of the impaired loans by portfolio class of loans	'	'	'
Loans with a specific valuation allowance, Recorded balance	28,194	28,194	29,595
Loans with a specific valuation allowance, Unpaid principal balance	29,463	29,463	36,887
Loans with a specific valuation allowance, Specific valuation allowance	6,662	6,662	7,716
Loans with a specific valuation allowance, Average balance	26,525	26,653	36,164
Loans without a specific valuation allowance, Recorded balance	97,372	97,372	95,687
Loans without a specific valuation allowance, Unpaid principal balance	120,914	120,914	102,798
Loans without a specific valuation allowance, Average balance	95,175	95,857	111,554
Recorded balance	125,566	125,566	125,282
Unpaid principal balance	150,377	150,377	139,685
Specific valuation allowance	6,662	6,662	7,716
Average balance	121,700	122,510	147,718
Other Commercial	'	'	'
Summary of the impaired loans by portfolio class of loans	'	'	'
Loans with a specific valuation allowance, Recorded balance	22,368	22,368	21,205
Loans with a specific valuation allowance, Unpaid principal balance	22,986	22,986	21,278
Loans with a specific valuation allowance, Specific valuation allowance	3,810	3,810	3,859
Loans with a specific valuation allowance, Average balance	21,780	21,321	22,665
Loans without a specific valuation allowance, Recorded balance	16,022	16,022	12,388
Loans without a specific valuation allowance, Unpaid principal balance	19,233	19,233	14,318
Loans without a specific valuation allowance, Average balance	15,768	14,011	19,733
Recorded balance	38,390	38,390	33,593
Unpaid principal balance	42,219	42,219	35,596
Specific valuation allowance	3,810	3,810	3,859
Average balance	37,548	35,332	42,398
Home Equity	'	'	'
Summary of the impaired loans by portfolio class of loans	'	'	'
Loans with a specific valuation allowance, Recorded balance	673	673	1,354
Loans with a specific valuation allowance, Unpaid principal balance	717	717	1,362
Loans with a specific valuation allowance, Specific valuation allowance	109	109	870
Loans with a specific valuation allowance, Average balance	495	737	1,390
Loans without a specific valuation allowance, Recorded balance	9,418	9,418	9,720
Loans without a specific valuation allowance, Unpaid principal balance	11,026	11,026	9,965
Loans without a specific valuation allowance, Average balance	8,766	9,017	11,993
Recorded balance	10,091	10,091	11,074
Unpaid principal balance	11,743	11,743	11,327
Specific valuation allowance	109	109	870
Average balance	9,261	9,754	13,383
Other Consumer	'	'	'
Summary of the impaired loans by portfolio class of loans	'	'	'
Loans with a specific valuation allowance, Recorded balance	3,492	3,492	3,271
Loans with a specific valuation allowance, Unpaid principal balance	3,771	3,771	3,275
Loans with a specific valuation allowance, Specific valuation allowance	1,059	1,059	1,409
Loans with a specific valuation allowance, Average balance	3,586	3,454	3,640
Loans without a specific valuation allowance, Recorded balance	2,275	2,275	2,653
Loans without a specific valuation allowance, Unpaid principal balance	2,404	2,404	2,718
Loans without a specific valuation allowance, Average balance	1,738	2,063	3,191
Recorded balance	5,767	5,767	5,924
Unpaid principal balance	6,175	6,175	5,993
Specific valuation allowance	1,059	1,059	1,409
Average balance	$5,324	$5,517	$6,831

Loans_Receivable_Aging_Analysi

Loans Receivable Aging Analysis (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Loan portfolio aging analysis	'	'
Accruing loans 30-59 days past due	$21,294	$17,454
Accruing loans 60-89 days past due	5,107	9,643
Accruing loans 90 days or more past due	174	1,479
Non-accrual loans	88,293	96,933
Total past due and non-accrual loans	114,868	125,509
Current loans receivable	3,886,231	3,271,916
Total loans receivable	4,001,099	3,397,425
Residential Real Estate	'	'
Loan portfolio aging analysis	'	'
Accruing loans 30-59 days past due	516	3,897
Accruing loans 60-89 days past due	824	1,870
Accruing loans 90 days or more past due	0	451
Non-accrual loans	12,604	14,237
Total past due and non-accrual loans	13,944	20,455
Current loans receivable	569,873	496,012
Total loans receivable	583,817	516,467
Commercial Real Estate	'	'
Loan portfolio aging analysis	'	'
Accruing loans 30-59 days past due	11,829	7,424
Accruing loans 60-89 days past due	2,419	3,745
Accruing loans 90 days or more past due	109	594
Non-accrual loans	53,536	55,687
Total past due and non-accrual loans	67,893	67,450
Current loans receivable	1,926,165	1,588,058
Total loans receivable	1,994,058	1,655,508
Other Commercial	'	'
Loan portfolio aging analysis	'	'
Accruing loans 30-59 days past due	5,854	2,020
Accruing loans 60-89 days past due	683	645
Accruing loans 90 days or more past due	35	197
Non-accrual loans	11,591	13,200
Total past due and non-accrual loans	18,163	16,062
Current loans receivable	816,066	607,335
Total loans receivable	834,229	623,397
Home Equity	'	'
Loan portfolio aging analysis	'	'
Accruing loans 30-59 days past due	1,828	2,872
Accruing loans 60-89 days past due	797	2,980
Accruing loans 90 days or more past due	28	188
Non-accrual loans	8,953	11,241
Total past due and non-accrual loans	11,606	17,281
Current loans receivable	361,906	386,644
Total loans receivable	373,512	403,925
Other Consumer	'	'
Loan portfolio aging analysis	'	'
Accruing loans 30-59 days past due	1,267	1,241
Accruing loans 60-89 days past due	384	403
Accruing loans 90 days or more past due	2	49
Non-accrual loans	1,609	2,568
Total past due and non-accrual loans	3,262	4,261
Current loans receivable	212,221	193,867
Total loans receivable	$215,483	$198,128

Troubled_Debt_Restructurings_D

Troubled Debt Restructurings (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
	Loan	Loan	Loan	Loan
Troubled Debt Restructurings	'	'	'	'
Troubled debt restructurings, Number of Loans	9	46	50	149
Troubled debt restructurings, Pre-modification recorded balance	$2,926	$38,125	$12,016	$66,580
Troubled debt restructurings, Post-modification recorded balance	3,141	35,475	12,418	61,944
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	2	3	10	17
Financing Receivable Modifications Subsequent Defaults Recorded Investment	363	1,792	2,772	10,204
Residential Real Estate	'	'	'	'
Troubled Debt Restructurings	'	'	'	'
Troubled debt restructurings, Number of Loans	2	1	9	9
Troubled debt restructurings, Pre-modification recorded balance	284	280	1,907	1,981
Troubled debt restructurings, Post-modification recorded balance	499	281	2,293	1,982
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	0	2	1	2
Financing Receivable Modifications Subsequent Defaults Recorded Investment	0	1,622	265	1,622
Commercial Real Estate	'	'	'	'
Troubled Debt Restructurings	'	'	'	'
Troubled debt restructurings, Number of Loans	4	21	17	61
Troubled debt restructurings, Pre-modification recorded balance	2,481	20,866	7,137	37,712
Troubled debt restructurings, Post-modification recorded balance	2,481	18,242	7,137	33,080
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	0	0	4	10
Financing Receivable Modifications Subsequent Defaults Recorded Investment	0	0	1,918	7,553
Other Commercial	'	'	'	'
Troubled Debt Restructurings	'	'	'	'
Troubled debt restructurings, Number of Loans	0	19	17	60
Troubled debt restructurings, Pre-modification recorded balance	0	16,601	2,572	25,033
Troubled debt restructurings, Post-modification recorded balance	0	16,571	2,588	25,025
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	2	0	5	3
Financing Receivable Modifications Subsequent Defaults Recorded Investment	363	0	589	801
Home Equity	'	'	'	'
Troubled Debt Restructurings	'	'	'	'
Troubled debt restructurings, Number of Loans	1	2	2	9
Troubled debt restructurings, Pre-modification recorded balance	57	219	147	1,314
Troubled debt restructurings, Post-modification recorded balance	57	222	147	1,317
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	0	1	0	1
Financing Receivable Modifications Subsequent Defaults Recorded Investment	0	170	0	170
Other Consumer	'	'	'	'
Troubled Debt Restructurings	'	'	'	'
Troubled debt restructurings, Number of Loans	2	3	5	10
Troubled debt restructurings, Pre-modification recorded balance	104	159	253	540
Troubled debt restructurings, Post-modification recorded balance	104	159	253	540
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	0	0	0	1
Financing Receivable Modifications Subsequent Defaults Recorded Investment	$0	$0	$0	$58

Loans_Receivable_Net_Details_T

Loans Receivable, Net (Details Textual) (USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Loans and Leases Receivable Disclosure	'	'	'
Net deferred fees, costs, premiums, and discounts included in loans receivable	$10,870,000	'	$1,379,000
Troubled Debt Restructurings	'	'	'
Percentage of Troubled Debt Restructurings Resulting from Extensions of Maturity Date	59.00%	56.00%	'
TDR With Pre Modification Loan Balance for Which Oreo Was Received	$14,695,000	$30,261,000	'
Commercial Real Estate	'	'	'
Troubled Debt Restructurings	'	'	'
Percentage of Troubled Debt Restructurings Resulting from Extensions of Maturity Date	63.00%	44.00%	'
Percentage of Troubled Debt Restructurings Resulting of Combination of Interest Rate Reduction Extension of Maturity Date or Reduction in Face Amount	25.00%	24.00%	'

Goodwill_Changes_in_the_Carryi

Goodwill Changes in the Carrying Value of Goodwill (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Goodwill Roll Forward	'	'	'	'
Net carrying value at beginning of period	$119,509	$106,100	$106,100	$106,100
Acquisitions	10,197	0	23,606	0
Net carrying value at end of period	$129,706	$106,100	$129,706	$106,100

Net_Carrying_Value_of_Goodwill

Net Carrying Value of Goodwill (Details) (USD $)	Sep. 30, 2013	Jun. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Gross carrying value of goodwill and the accumulated impairment charge	'	'	'	'	'	'
Gross carrying value	$169,865	'	$146,259	'	'	'
Accumulated impairment charge	-40,159	'	-40,159	'	'	'
Net carrying value	$129,706	$119,509	$106,100	$106,100	$106,100	$106,100

Interest_Rate_Swap_Summary_Det

Interest Rate Swap Summary (Details) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013
Interest Rate Swap One	'
Derivatives	'
Derivative Liability, Notional Amount	$160,000
Debt Instrument, Description of Variable Rate Basis	'3 month LIBOR	[1]
Derivative, Fixed Interest Rate	3.38%	[1]
Derivative, Inception Date	21-Oct-14	[2]
Derivative, Maturity Date	21-Oct-21	[2]
Interest Rate Swap Two	'
Derivatives	'
Derivative Liability, Notional Amount	$100,000
Debt Instrument, Description of Variable Rate Basis	'3B monthB LIBOR	[1]
Derivative, Fixed Interest Rate	2.50%	[1]
Derivative, Inception Date	30-Nov-15	[2]
Derivative, Maturity Date	30-Nov-22	[2]
[1]	The Company pays the fixed interest rate and the counterparties pay the Company the variable interest rate.
[2]	No cash will be exchanged prior to the term.

Fair_Value_of_Interest_Rate_Sw

Fair Value of Interest Rate Swaps (Details) (Interest Rate Swaps, Designated as Hedging Instrument, Other Liabilities, USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Interest Rate Swaps | Designated as Hedging Instrument | Other Liabilities	'	'
Fair value of interest rate derivative financial instruments	'	'
Fair Value	$2,004	$16,832

Derivatives_and_Hedging_Activi2

Derivatives and Hedging Activities (Details Textual) (USD $)	Sep. 30, 2013
Derivatives	'
Investment securities pledged to counterparties as collateral	$7,856,000
Collateral pledged from the counterparties to the Company	$0

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Accumulated Other Comprehensive Income (Loss)	'	'
Accumulated Other Comprehensive Income (Loss), Net of Tax	$9,983	$47,962
Accumulated Net Unrealized Gain (Loss) on Available-For-Sale Securities	'	'
Accumulated Other Comprehensive Income (Loss)	'	'
Accumulated Other Comprehensive Income (Loss), before Tax	18,343	95,328
Tax effect	-7,136	-37,083
Accumulated Other Comprehensive Income (Loss), Net of Tax	11,207	58,245
Accumulated Net Unrealized Gain (Loss) on Derivatives Used for Cash Flow Hedges	'	'
Accumulated Other Comprehensive Income (Loss)	'	'
Accumulated Other Comprehensive Income (Loss), before Tax	-2,004	-16,832
Tax effect	780	6,549
Accumulated Other Comprehensive Income (Loss), Net of Tax	($1,224)	($10,283)

Earnings_Per_Share_Details

Earnings Per Share (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Basic and diluted earnings per share computation	'	'	'	'
Net income available to common stockholders, basic and diluted	$25,628	$19,444	$69,098	$54,758
Average outstanding shares - basic	73,945,523	71,933,141	72,804,321	71,925,664
Add: dilutive stock options and awards	76,348	40,844	65,154	97
Average outstanding shares - diluted	74,021,871	71,973,985	72,869,475	71,925,761
Basic earnings per share	$0.35	$0.27	$0.95	$0.76
Diluted earnings per share	$0.35	$0.27	$0.95	$0.76
Earnings Per Share	'	'	'	'
Options excluded from the diluted average outstanding share calculation	'	'	49,932	903,945

Fair_Value_Measurements_on_a_R

Fair Value Measurements on a Recurring Basis (Details) (Recurring Measurements, USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Financial Assets	'	'
Total assets measured at fair value on a recurring basis	$3,318,953	$3,683,005
Financial Liabilities	'	'
Total liabilities measured at fair value on a recurring basis	2,004	16,832
Interest rate swaps	'	'
Financial Liabilities	'	'
Interest rate swaps	2,004	16,832
U.S. government and federal agency	'	'
Financial Assets	'	'
Investment securities, available-for-sale	'	202
U.S. government sponsored enterprises	'	'
Financial Assets	'	'
Investment securities, available-for-sale	11,556	17,480
State and local governments	'	'
Financial Assets	'	'
Investment securities, available-for-sale	1,341,384	1,214,518
Corporate bonds	'	'
Financial Assets	'	'
Investment securities, available-for-sale	442,845	288,795
Collateralized debt obligations	'	'
Financial Assets	'	'
Investment securities, available-for-sale	'	1,708
Residential mortgage-backed securities	'	'
Financial Assets	'	'
Investment securities, available-for-sale	1,523,168	2,160,302
Level 1	'	'
Financial Assets	'	'
Total assets measured at fair value on a recurring basis	0	0
Financial Liabilities	'	'
Total liabilities measured at fair value on a recurring basis	0	0
Level 1 | Interest rate swaps	'	'
Financial Liabilities	'	'
Interest rate swaps	0	0
Level 1 | U.S. government and federal agency	'	'
Financial Assets	'	'
Investment securities, available-for-sale	'	0
Level 1 | U.S. government sponsored enterprises	'	'
Financial Assets	'	'
Investment securities, available-for-sale	0	0
Level 1 | State and local governments	'	'
Financial Assets	'	'
Investment securities, available-for-sale	0	0
Level 1 | Corporate bonds	'	'
Financial Assets	'	'
Investment securities, available-for-sale	0	0
Level 1 | Collateralized debt obligations	'	'
Financial Assets	'	'
Investment securities, available-for-sale	'	0
Level 1 | Residential mortgage-backed securities	'	'
Financial Assets	'	'
Investment securities, available-for-sale	0	0
Level 2	'	'
Financial Assets	'	'
Total assets measured at fair value on a recurring basis	3,318,953	3,683,005
Financial Liabilities	'	'
Total liabilities measured at fair value on a recurring basis	2,004	16,832
Level 2 | Interest rate swaps	'	'
Financial Liabilities	'	'
Interest rate swaps	2,004	16,832
Level 2 | U.S. government and federal agency	'	'
Financial Assets	'	'
Investment securities, available-for-sale	'	202
Level 2 | U.S. government sponsored enterprises	'	'
Financial Assets	'	'
Investment securities, available-for-sale	11,556	17,480
Level 2 | State and local governments	'	'
Financial Assets	'	'
Investment securities, available-for-sale	1,341,384	1,214,518
Level 2 | Corporate bonds	'	'
Financial Assets	'	'
Investment securities, available-for-sale	442,845	288,795
Level 2 | Collateralized debt obligations	'	'
Financial Assets	'	'
Investment securities, available-for-sale	'	1,708
Level 2 | Residential mortgage-backed securities	'	'
Financial Assets	'	'
Investment securities, available-for-sale	1,523,168	2,160,302
Level 3	'	'
Financial Assets	'	'
Total assets measured at fair value on a recurring basis	0	0
Financial Liabilities	'	'
Total liabilities measured at fair value on a recurring basis	0	0
Level 3 | Interest rate swaps	'	'
Financial Liabilities	'	'
Interest rate swaps	0	0
Level 3 | U.S. government and federal agency	'	'
Financial Assets	'	'
Investment securities, available-for-sale	'	0
Level 3 | U.S. government sponsored enterprises	'	'
Financial Assets	'	'
Investment securities, available-for-sale	0	0
Level 3 | State and local governments	'	'
Financial Assets	'	'
Investment securities, available-for-sale	0	0
Level 3 | Corporate bonds	'	'
Financial Assets	'	'
Investment securities, available-for-sale	0	0
Level 3 | Collateralized debt obligations	'	'
Financial Assets	'	'
Investment securities, available-for-sale	'	0
Level 3 | Residential mortgage-backed securities	'	'
Financial Assets	'	'
Investment securities, available-for-sale	$0	$0

Fair_Value_Measurements_on_a_N

Fair Value Measurements on a Non-Recurring Basis (Details) (Non-Recurring Measurements, USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Assets with a recorded change resulting from re-measuring at fair value on a non-recurring basis	'	'
Other real estate owned	$7,646	$13,983
Collateral-dependent impaired loans, net of ALLL	19,066	22,966
Total assets measured at fair value on a non-recurring basis	26,712	36,949
Level 1	'	'
Assets with a recorded change resulting from re-measuring at fair value on a non-recurring basis	'	'
Other real estate owned	0	0
Collateral-dependent impaired loans, net of ALLL	0	0
Total assets measured at fair value on a non-recurring basis	0	0
Level 2	'	'
Assets with a recorded change resulting from re-measuring at fair value on a non-recurring basis	'	'
Other real estate owned	0	0
Collateral-dependent impaired loans, net of ALLL	0	0
Total assets measured at fair value on a non-recurring basis	0	0
Level 3	'	'
Assets with a recorded change resulting from re-measuring at fair value on a non-recurring basis	'	'
Other real estate owned	7,646	13,983
Collateral-dependent impaired loans, net of ALLL	19,066	22,966
Total assets measured at fair value on a non-recurring basis	$26,712	$36,949

Quantitative_Information_about

Quantitative Information about Level 3 Fair Value Measurements (Details) (Non-Recurring Measurements, USD $)

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

In Thousands, unless otherwise specified

Level 3

Level 3

Other real estate owned

Other real estate owned

Other real estate owned

Other real estate owned

Other real estate owned

Other real estate owned

Other real estate owned

Other real estate owned

Other real estate owned

Collateral-dependent Impaired Loans, Net of ALLL

Collateral-dependent Impaired Loans, Net of ALLL

Collateral-dependent Impaired Loans, Net of ALLL

Collateral-dependent Impaired Loans, Net of ALLL

Collateral-dependent Impaired Loans, Net of ALLL

Collateral-dependent Impaired Loans, Net of ALLL

Collateral-dependent Impaired Loans, Net of ALLL

Collateral-dependent Impaired Loans, Net of ALLL

Collateral-dependent Impaired Loans, Net of ALLL

Collateral-dependent Impaired Loans, Net of ALLL

Collateral-dependent Impaired Loans, Net of ALLL

Collateral-dependent Impaired Loans, Net of ALLL

Collateral-dependent Impaired Loans, Net of ALLL

Collateral-dependent Impaired Loans, Net of ALLL

Collateral-dependent Impaired Loans, Net of ALLL

Collateral-dependent Impaired Loans, Net of ALLL

Collateral-dependent Impaired Loans, Net of ALLL

Level 3

Sales Comparison Approach

Combined Approach

Minimum Range

Minimum Range

Maximum Range

Maximum Range

Weighted Average Range

Weighted Average Range

Level 3

Cost Approach

Income Approach

Sales Comparison Approach

Combined Approach

Minimum Range

Minimum Range

Minimum Range

Minimum Range

Maximum Range

Maximum Range

Maximum Range

Maximum Range

Weighted Average Range

Weighted Average Range

Weighted Average Range

Weighted Average Range

Level 3

Level 3

Sales Comparison Approach

Combined Approach

Sales Comparison Approach

Combined Approach

Sales Comparison Approach

Combined Approach

Level 3

Level 3

Level 3

Level 3

Cost Approach

Income Approach

Sales Comparison Approach

Combined Approach

Cost Approach

Income Approach

Sales Comparison Approach

Combined Approach

Cost Approach

Income Approach

Sales Comparison Approach

Combined Approach

Level 3

Level 3

Level 3

Level 3

Level 3

Level 3

Level 3

Level 3

Level 3

Level 3

Level 3

Level 3

Level 3

Level 3

Level 3

Level 3

Level 3

Level 3

Quantitative Information About Level 3 Fair Value Measurements

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fair Value

$26,712

$36,949

$26,712

$36,949

$7,646

$6,828

$818

'

'

'

'

'

'

$19,066

$442

$2,553

$13,700

$2,371

'

'

'

'

'

'

'

'

'

'

'

'

Unobservable Inputs

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Selling Costs

'

'

'

'

'

'

'

1.00%

[1]

5.00%

[1]

11.00%

[1]

5.00%

[1]

7.00%

[1]

5.00%

[1]

'

'

'

'

'

10.00%

[1]

8.00%

[1]

0.00%

[1]

8.00%

[1]

50.00%

[1]

8.00%

[1]

10.00%

[1]

8.00%

[1]

19.20%

[1]

8.00%

[1]

8.00%

[1]

8.00%

[1]

Discount Rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

8.30%

0.00%

'

'

8.30%

0.00%

'

'

8.30%

0.00%

'

Adjustment to Comparables

'

'

'

'

'

'

'

0.00%

[1]

25.00%

[1]

10.00%

[1]

25.00%

[1]

0.00%

[1]

25.00%

[1]

'

'

'

'

'

'

'

0.00%

[1]

10.00%

[1]

'

'

1.00%

[1]

36.00%

[1]

'

'

0.00%

[1]

22.50%

[1]

[1]

The range for selling costs and adjustments to comparables indicate reductions to the fair value.

Carrying_Amount_and_Fair_Value

Carrying Amount and Fair Value of Financial Instruments (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Carrying Amount	'	'
Financial assets	'	'
Cash and cash equivalents	$254,684	$187,040
Investment securities, available-for-sale	3,318,953	3,683,005
Loans held for sale	61,505	145,501
Loans receivable, net of ALLL	3,870,334	3,266,571
Accrued interest receivable	44,261	37,770
Non-marketable equity securities	52,192	48,812
Total financial assets	7,601,929	7,368,699
Financial liabilities	'	'
Deposits	5,612,880	5,364,461
FHLB advances	967,382	997,013
Repurchase agreements and other borrowed funds	322,779	299,540
Subordinated debentures	125,526	125,418
Accrued interest payable	3,568	4,675
Interest rate swaps	2,004	16,832
Total financial liabilities	7,034,139	6,807,939
Estimated Fair Value | Level 1	'	'
Financial assets	'	'
Cash and cash equivalents	254,684	187,040
Investment securities, available-for-sale	0	0
Loans held for sale	61,505	145,501
Loans receivable, net of ALLL	0	0
Accrued interest receivable	44,261	37,770
Non-marketable equity securities	0	0
Total financial assets	360,450	370,311
Financial liabilities	'	'
Deposits	4,153,782	3,585,126
FHLB advances	0	0
Repurchase agreements and other borrowed funds	0	0
Subordinated debentures	0	0
Accrued interest payable	3,568	4,675
Interest rate swaps	0	0
Total financial liabilities	4,157,350	3,589,801
Estimated Fair Value | Level 2	'	'
Financial assets	'	'
Cash and cash equivalents	0	0
Investment securities, available-for-sale	3,318,953	3,683,005
Loans held for sale	0	0
Loans receivable, net of ALLL	3,758,724	3,184,987
Accrued interest receivable	0	0
Non-marketable equity securities	52,192	48,812
Total financial assets	7,129,869	6,916,804
Financial liabilities	'	'
Deposits	1,486,996	1,789,134
FHLB advances	986,292	1,027,101
Repurchase agreements and other borrowed funds	322,779	299,540
Subordinated debentures	72,554	70,895
Accrued interest payable	0	0
Interest rate swaps	2,004	16,832
Total financial liabilities	2,870,625	3,203,502
Estimated Fair Value | Level 3	'	'
Financial assets	'	'
Cash and cash equivalents	0	0
Investment securities, available-for-sale	0	0
Loans held for sale	0	0
Loans receivable, net of ALLL	194,190	186,201
Accrued interest receivable	0	0
Non-marketable equity securities	0	0
Total financial assets	194,190	186,201
Financial liabilities	'	'
Deposits	0	0
FHLB advances	0	0
Repurchase agreements and other borrowed funds	0	0
Subordinated debentures	0	0
Accrued interest payable	0	0
Interest rate swaps	0	0
Total financial liabilities	$0	$0

Consideration_Transferred_Iden

Consideration Transferred, Identifiable Net Assets Acquired and Goodwill Recognized (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Fair value of consideration transferred	'	'	'	'
Fair value of Company shares issued, net of equity issuance costs	'	'	$45,033	'
Cash consideration for outstanding shares	'	'	24,858	'
Total fair value of consideration transferred	'	'	69,891	'
Identifiable assets acquired	'	'	'	'
Cash and cash equivalents	51,013	'	51,013	'
Investment securities, available-for-sale	123,701	'	123,701	'
Loans receivable	387,185	'	387,185	'
Core deposit intangible	5,739	'	5,739	'
Accrued income and other assets	39,325	'	39,325	'
Total identifiable assets acquired	606,963	'	606,963	'
Liabilities assumed	'	'	'	'
Deposits	550,177	'	550,177	'
Federal Home Loan Bank advances and other borrowed funds	5,467	'	5,467	'
Accrued expenses and other liabilities	5,034	'	5,034	'
Total liabilities assumed	560,678	'	560,678	'
Total identifiable net assets	46,285	'	46,285	'
Goodwill recognized	10,197	0	23,606	0
Wheatland Bankshares	'	'	'	'
Fair value of consideration transferred	'	'	'	'
Fair value of Company shares issued, net of equity issuance costs	'	'	28,290	'
Cash consideration for outstanding shares	'	'	11,025	'
Total fair value of consideration transferred	'	'	39,315	'
Identifiable assets acquired	'	'	'	'
Cash and cash equivalents	23,148	'	23,148	'
Investment securities, available-for-sale	75,643	'	75,643	'
Loans receivable	171,199	'	171,199	'
Core deposit intangible	2,079	'	2,079	'
Accrued income and other assets	15,063	'	15,063	'
Total identifiable assets acquired	287,132	'	287,132	'
Liabilities assumed	'	'	'	'
Deposits	255,197	'	255,197	'
Federal Home Loan Bank advances and other borrowed funds	5,467	'	5,467	'
Accrued expenses and other liabilities	562	'	562	'
Total liabilities assumed	261,226	'	261,226	'
Total identifiable net assets	25,906	'	25,906	'
Goodwill recognized	'	'	13,409	'
North Cascades Bancshares	'	'	'	'
Fair value of consideration transferred	'	'	'	'
Fair value of Company shares issued, net of equity issuance costs	'	'	16,743	'
Cash consideration for outstanding shares	'	'	13,833	'
Total fair value of consideration transferred	'	'	30,576	'
Identifiable assets acquired	'	'	'	'
Cash and cash equivalents	27,865	'	27,865	'
Investment securities, available-for-sale	48,058	'	48,058	'
Loans receivable	215,986	'	215,986	'
Core deposit intangible	3,660	'	3,660	'
Accrued income and other assets	24,262	'	24,262	'
Total identifiable assets acquired	319,831	'	319,831	'
Liabilities assumed	'	'	'	'
Deposits	294,980	'	294,980	'
Federal Home Loan Bank advances and other borrowed funds	0	'	0	'
Accrued expenses and other liabilities	4,472	'	4,472	'
Total liabilities assumed	299,452	'	299,452	'
Total identifiable net assets	20,379	'	20,379	'
Goodwill recognized	'	'	$10,197	'

Pro_Forma_Summary_Details

Pro Forma Summary (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Business Acquisition, Pro Forma Information [Abstract]	'	'	'	'
Net interest income and non-interest income	$86,940	$77,095	$249,224	$251,525
Net income	$24,756	$20,126	$69,846	$58,525

Mergers_and_Acquisitions_Detai

Mergers and Acquisitions (Details Textual) (USD $)	9 Months Ended
	Sep. 30, 2013
Business Acquisition	'
Business Combination, Consideration Transferred	$69,891,000
Cash consideration for outstanding shares	24,858,000
Wheatland Bankshares	'
Business Acquisition	'
Effective Date of Acquisition	31-May-13
Percentage of Outstanding Common Stock Acquired	100.00%
Business Combination, Consideration Transferred	39,315,000
Number of Shares Issued for Aquisition	1,455,256
Cash consideration for outstanding shares	11,025,000
Loans receivable	171,199,000
Loans Receivable Acquired, Gross Principal and Contractual Interest Due	176,698,000
Loans Receivable Acquired, Gross Principal and Contractual Interest Due, Expected to be Uncollectible	0
Third-party Acquisition Related Costs	594,000
Net interest income and non-interest income	4,605,000
Net income	1,338,000
North Cascades Bancshares	'
Business Acquisition	'
Effective Date of Acquisition	31-Jul-13
Percentage of Outstanding Common Stock Acquired	100.00%
Business Combination, Consideration Transferred	30,576,000
Number of Shares Issued for Aquisition	687,876
Cash consideration for outstanding shares	13,833,000
Loans receivable	215,986,000
Loans Receivable Acquired, Gross Principal and Contractual Interest Due	223,949,000
Loans Receivable Acquired, Gross Principal and Contractual Interest Due, Expected to be Uncollectible	0
Third-party Acquisition Related Costs	478,000
Net interest income and non-interest income	2,662,000
Net income	$510,000