Loans and Credit Quality (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable Allowance Covered And Noncovered	$ 82,149	$ (90,643)	$ 82,149	$ (90,643)	$ (81,180)	$ 82,034	$ (94,519)	$ (91,968)
Allowance for Loan and Lease Losses, Write-offs	5,434	4,698	6,933	5,787
Allowance for Loan and Lease Loss, Recovery of Bad Debts	1,242	2,664	1,931	3,627
Provision for Loan and Lease Losses	(5,161)	(1,842)	(5,117)	(835)
Loans held for investment, net	11,190,105	4,419,686	11,190,105	4,419,686
Loans and Leases Receivable, Allowance	(82,149)	(90,643)	(82,149)	(90,643)
Loans and Leases Receivable, Net Reported Amount, Covered	381,810		381,810			361,003
Loans and Leases Receivable Net Of Deferred Income Covered And Noncovered	11,190,105		11,190,105			4,312,352
Loans and Leases Receivable, Gross						3,929,556
Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable Allowance Covered And Noncovered	(22,276)	(31,804)	(22,276)	(31,804)
Loans and Leases Receivable, Net Amount						2,422,107
Loans and Leases Receivable, Gross	5,601,020		5,601,020			2,795,998
Real Estate Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable Allowance Covered And Noncovered	(4,302)	(3,432)	(4,302)	(3,432)
Loans and Leases Receivable, Net Amount						207,779
Loans and Leases Receivable, Gross	310,534		310,534			219,517
Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable Allowance Covered And Noncovered	(35,530)	(26,343)	(35,530)	(26,343)
Loans and Leases Receivable, Net Amount						1,244,785
Loans and Leases Receivable, Gross	5,225,694		5,225,694			1,242,750
Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable Allowance Covered And Noncovered	(3,415)	(1,667)	(3,415)	(1,667)
Loans and Leases Receivable, Net Amount						54,885
Loans and Leases Receivable, Gross	63,276		63,276			55,070
Purchased Credit Impaired Loans and Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Allowance for Loan and Lease Losses, Write-offs	4,604	64	4,553	0
Allowance for Loan and Lease Loss, Recovery of Bad Debts	0	0	0	33
Provision for Loan and Lease Losses	(30)	(1,842)	(614)	(1,295)
Loans held for investment, net	398,436		398,436
Loans and Leases Receivable, Allowance, Covered	16,626	27,397	16,626	27,397	21,200	21,793	29,303	26,069
Financing Receivable, Allowance for Credit Losses, Acquired with Deteriorated Credit Quality	16,626	27,397	16,626	27,397
Loans and Leases Receivable, Net Reported Amount, Covered	398,436		398,436			361,003
Financing Receivable, Acquired with Deteriorated Credit Quality	398,436	494,389	398,436	494,389
Loans and Leases Receivable, Gross	398,436		398,436			382,796
Purchased Credit Impaired Loans and Leases [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Net Amount	359,130		359,130			371,134
Loans and Leases Receivable, Gross	395,500		395,500			412,791
Purchased Credit Impaired Loans and Leases [Member] | Real Estate Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Net Amount	10,030		10,030			10,427
Loans and Leases Receivable, Gross	10,763		10,763			12,015
Purchased Credit Impaired Loans and Leases [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Net Amount	28,940		28,940			974
Loans and Leases Receivable, Gross	29,824		29,824			3,021
Purchased Credit Impaired Loans and Leases [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Net Amount	336		336			261
Loans and Leases Receivable, Gross	408		408			424
NonCovered [Member]
Financing Receivable, Recorded Investment [Line Items]
Impaired Financing Receivable, Related Allowance	15,335		15,335			7,600
Allowance for Loan and Lease Losses, Write-offs	(830)	4,634	(2,380)	5,787
Allowance for Loan and Lease Loss, Recovery of Bad Debts	1,242	2,664	1,931	3,594
Provision for Loan and Lease Losses	(5,131)	0	(5,731)	(460)
Loans held for investment, net	10,791,669		10,791,669			3,929,556
Loans and Leases Receivable, Allowance	65,523	63,246	65,523	63,246	59,980	60,241	65,216	65,899
Financing Receivable, Individually Evaluated for Impairment	15,335	11,120	15,335	11,120
Financing Receivable, Collectively Evaluated for Impairment	50,188	52,126	50,188	52,126
Loans and Leases Receivable, Net Amount	10,791,669		10,791,669			3,869,315
Impaired Financing Receivable, Recorded Investment	130,543		130,543			88,422
Financing Receivable, Individually Evaluated for Impairment	130,543	135,232	130,543	135,232
Financing Receivable, Collectively Evaluated for Impairment	10,661,126	3,790,998	10,661,126	3,790,998
Loans and Leases Receivable, Gross	10,791,669	3,926,230	10,791,669	3,926,230		3,929,556
NonCovered [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable Allowance Covered And Noncovered	(22,276)	(31,804)	(22,276)	(31,804)	(24,352)	(26,078)	(37,265)	(38,700)
Impaired Financing Receivable, Related Allowance	2,245		2,245			2,188
Allowance for Loan and Lease Losses, Write-offs	487	3,237	581	3,559
Allowance for Loan and Lease Loss, Recovery of Bad Debts	376	1,336	636	1,513
Provision for Loan and Lease Losses	(1,965)	(3,560)	(3,857)	(4,850)
Financing Receivable, Individually Evaluated for Impairment		3,548		3,548
Financing Receivable, Collectively Evaluated for Impairment	20,031	28,256	20,031	28,256
Loans and Leases Receivable, Net Amount	5,236,452		5,236,452
Impaired Financing Receivable, Recorded Investment	62,287		62,287			62,276
Financing Receivable, Individually Evaluated for Impairment		96,293		96,293
Financing Receivable, Collectively Evaluated for Impairment	5,174,165	2,463,346	5,174,165	2,463,346
Loans and Leases Receivable, Gross	5,236,452	2,559,639	5,236,452	2,559,639		2,422,107
NonCovered [Member] | Real Estate Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable Allowance Covered And Noncovered	(4,302)	(3,432)	(4,302)	(3,432)	(4,103)	(4,298)	(3,300)	(3,221)
Impaired Financing Receivable, Related Allowance	238		238			169
Allowance for Loan and Lease Losses, Write-offs	0	0	0
Allowance for Loan and Lease Loss, Recovery of Bad Debts	64	12	88	335
Provision for Loan and Lease Losses	(135)	(120)	(84)	(124)
Financing Receivable, Individually Evaluated for Impairment		62		62
Financing Receivable, Collectively Evaluated for Impairment	4,064	3,370	4,064	3,370
Loans and Leases Receivable, Net Amount	298,477		298,477
Impaired Financing Receivable, Recorded Investment	12,797		12,797			7,512
Financing Receivable, Individually Evaluated for Impairment		14,966		14,966
Financing Receivable, Collectively Evaluated for Impairment	285,680	182,810	285,680	182,810
Loans and Leases Receivable, Gross	298,477	197,776	298,477	197,776		207,779
NonCovered [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable Allowance Covered And Noncovered	(35,530)	(26,343)	(35,530)	(26,343)	(27,740)	(26,921)	(23,157)	(22,252)
Impaired Financing Receivable, Related Allowance	12,531		12,531			5,003
Allowance for Loan and Lease Losses, Write-offs	(326)	1,370	(1,767)	2,192
Allowance for Loan and Lease Loss, Recovery of Bad Debts	587	1,297	965	1,704
Provision for Loan and Lease Losses	(7,529)	(3,259)	(9,411)	(4,579)
Financing Receivable, Individually Evaluated for Impairment		7,270		7,270
Financing Receivable, Collectively Evaluated for Impairment	22,999	19,073	22,999	19,073
Loans and Leases Receivable, Net Amount	5,193,735		5,193,735
Impaired Financing Receivable, Recorded Investment	51,488		51,488			17,932
Financing Receivable, Individually Evaluated for Impairment		23,275		23,275
Financing Receivable, Collectively Evaluated for Impairment	5,142,247	1,116,944	5,142,247	1,116,944
Loans and Leases Receivable, Gross	5,193,735	1,140,219	5,193,735	1,140,219		1,244,785
NonCovered [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable Allowance Covered And Noncovered	(3,415)	(1,667)	(3,415)	(1,667)	(3,785)	(2,944)	(1,494)	(1,726)
Impaired Financing Receivable, Related Allowance	321		321			240
Allowance for Loan and Lease Losses, Write-offs	17	27	32	36
Allowance for Loan and Lease Loss, Recovery of Bad Debts	215	19	242	42
Provision for Loan and Lease Losses	(568)	(181)	(261)	(65)
Financing Receivable, Individually Evaluated for Impairment		240		240
Financing Receivable, Collectively Evaluated for Impairment	3,094	1,427	3,094	1,427
Loans and Leases Receivable, Net Amount	63,005		63,005
Impaired Financing Receivable, Recorded Investment	3,971		3,971			702
Financing Receivable, Individually Evaluated for Impairment		698		698
Financing Receivable, Collectively Evaluated for Impairment	59,034	27,898	59,034	27,898
Loans and Leases Receivable, Gross		$ 28,596		$ 28,596		$ 54,885