The balance of financing receivables that were acquired with deteriorated credit quality.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

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A valuation allowance for financing receivables that are expected to be uncollectible.

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-Publisher FASB

-Name Accounting Standards Codification

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The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

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Amount of recovery of financing receivables doubtful of collection that were previously charged off.

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-Publisher FASB

-Name Accounting Standards Codification

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Amount of direct write-downs of financing receivables charged against the allowance.

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The balance of financing receivables that were collectively evaluated for impairment.

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Amount of unpaid principal balance of impaired financing receivables with related allowance for credit losses and without related allowance for credit losses.

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Amount of expense related to estimated loss from loan and lease transactions.

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Loans and Allowance for Loan Losses - Schedule of Allowances for Loan Losses by Portfolio Segment (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				$ 22,377				$ 23,593	$ 22,377	$ 23,593	$ 35,156
Provision for loan losses	888us-gaap_ProvisionForLoanAndLeaseLosses	1,669us-gaap_ProvisionForLoanAndLeaseLosses	1,365us-gaap_ProvisionForLoanAndLeaseLosses	1,726us-gaap_ProvisionForLoanAndLeaseLosses	1,478us-gaap_ProvisionForLoanAndLeaseLosses	2,920us-gaap_ProvisionForLoanAndLeaseLosses	4,165us-gaap_ProvisionForLoanAndLeaseLosses	2,923us-gaap_ProvisionForLoanAndLeaseLosses	5,648us-gaap_ProvisionForLoanAndLeaseLosses	11,486us-gaap_ProvisionForLoanAndLeaseLosses	31,089us-gaap_ProvisionForLoanAndLeaseLosses
Loans charged off									(9,560)	(14,823)	(43,801)
Recoveries of loans previously charged off									2,692	2,121	1,149
Ending balance	21,157				22,377				21,157	22,377	23,593
Loans individually evaluated for impairment	3,890				3,585				3,890	3,585	4,554
Loans collectively evaluated for impairment	17,267				18,792				17,267	18,792	19,039
Individually evaluated for impairment	27,649				39,203				27,649	39,203	45,320
Collectively evaluated for impairment	2,563,652				2,134,029				2,563,652	2,134,029	1,630,290
Acquired with deteriorated credit quality	244,098				284,212				244,098	284,212	282,737
Ending balance	2,835,399				2,457,444				2,835,399	2,457,444	1,958,347
Purchased Non-Covered Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Provision for loan losses									84
Loans charged off									(84)
Collectively evaluated for impairment	579,172				381,588				579,172	381,588
Acquired with deteriorated credit quality	95,067				67,165				95,067	67,165
Ending balance	26,885				19,970				26,885	19,970
Covered Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Provision for loan losses									843	1,539	2,638
Loans charged off									(1,851)	(1,539)	(2,638)
Recoveries of loans previously charged off									1,008
Collectively evaluated for impairment	122,248				173,190				122,248	173,190	224,975
Acquired with deteriorated credit quality	149,031				217,047				149,031	217,047	282,737
Ending balance	65,555				106,690				65,555	106,690	507,712
Commercial, Financial & Agricultural [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				1,823				2,439	1,823	2,439	2,918
Provision for loan losses									1,427	711	815
Loans charged off									(1,567)	(1,759)	(1,451)
Recoveries of loans previously charged off									321	432	157
Ending balance	2,004				1,823				2,004	1,823	2,439
Loans individually evaluated for impairment	375				356				375	356	659
Loans collectively evaluated for impairment	1,629				1,467				1,629	1,467	1,780
Individually evaluated for impairment	490				3,457				490	3,457	3,351
Collectively evaluated for impairment	319,164				240,916				319,164	240,916	170,866
Ending balance	319,654				244,373				319,654	244,373	174,217
Commercial, Financial & Agricultural [Member] \| Purchased Non-Covered Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Ending balance	499				19				499	19
Commercial, Financial & Agricultural [Member] \| Covered Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Ending balance	10,845				9,680				10,845	9,680
Real Estate - Construction & Development [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				5,538				5,343	5,538	5,343	9,438
Provision for loan losses									(265)	1,742	5,245
Loans charged off									(592)	(2,020)	(9,380)
Recoveries of loans previously charged off									349	473	40
Ending balance	5,030				5,538				5,030	5,538	5,343
Loans individually evaluated for impairment	743				407				743	407	611
Loans collectively evaluated for impairment	4,287				5,131				4,287	5,131	4,732
Individually evaluated for impairment	3,709				3,581				3,709	3,581	7,617
Collectively evaluated for impairment	157,798				142,790				157,798	142,790	106,582
Ending balance	161,507				146,371				161,507	146,371	114,199
Real Estate - Construction & Development [Member] \| Purchased Non-Covered Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Ending balance	2,210				5,719				2,210	5,719
Real Estate - Construction & Development [Member] \| Covered Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Ending balance	11,621				20,915				11,621	20,915
Commercial And Farmland [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				8,393				9,157	8,393	9,157	14,226
Provision for loan losses									3,444	2,777	15,000
Loans charged off									(3,288)	(3,571)	(20,551)
Recoveries of loans previously charged off									274	30	482
Ending balance	8,823				8,393				8,823	8,393	9,157
Loans individually evaluated for impairment	1,861				1,427				1,861	1,427	2,228
Loans collectively evaluated for impairment	6,962				6,966				6,962	6,966	6,929
Individually evaluated for impairment	14,546				15,240				14,546	15,240	21,332
Collectively evaluated for impairment	892,978				793,083				892,978	793,083	710,990
Ending balance	907,524				808,323				907,524	808,323	732,322
Commercial And Farmland [Member] \| Purchased Non-Covered Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Ending balance	13,520				4,563				13,520	4,563
Commercial And Farmland [Member] \| Covered Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Ending balance	23,349				46,612				23,349	46,612
Real Estate - Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				6,034				5,898	6,034	5,898	8,128
Provision for loan losses									(452)	4,463	6,267
Loans charged off									(1,707)	(5,215)	(8,722)
Recoveries of loans previously charged off									254	888	225
Ending balance	4,129				6,034				4,129	6,034	5,898
Loans individually evaluated for impairment	911				1,395				911	1,395	1,056
Loans collectively evaluated for impairment	3,218				4,639				3,218	4,639	4,842
Individually evaluated for impairment	8,904				16,925				8,904	16,925	13,020
Collectively evaluated for impairment	447,202				349,957				447,202	349,957	333,460
Ending balance	456,106				366,882				456,106	366,882	346,480
Real Estate - Residential [Member] \| Purchased Non-Covered Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Ending balance	10,487				9,612				10,487	9,612
Real Estate - Residential [Member] \| Covered Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Ending balance	19,629				29,089				19,629	29,089
Consumer Installment Loans and Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance				589				756	589	756	446
Provision for loan losses									567	254	1,124
Loans charged off									(471)	(719)	(1,059)
Recoveries of loans previously charged off									486	298	245
Ending balance	1,171				589				1,171	589	756
Loans collectively evaluated for impairment	1,171				589				1,171	589	756
Collectively evaluated for impairment	45,090				52,505				45,090	52,505	83,417
Ending balance	$ 45,090				$ 52,505				$ 45,090	$ 52,505	$ 83,417