Loans and Credit Quality (Details 1) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross			$ 3,929,556
Loans and Leases Receivable Gross Carrying Amount Covered And Noncovered	11,200,524		4,313,335	4,420,619
Loans and Leases Receivable Net Of Deferred Income Covered And Noncovered	11,190,105		4,312,352
Loans held for investment, net	11,190,105			4,419,686
Loans and Leases Receivable, Net Reported Amount, Covered	381,810		361,003
Loans and Leases Receivable, Deferred Income	(10,419)		(983)
Loans and Leases Receivable, Allowance	82,149			90,643
Loans and Leases Receivable Allowance Covered And Noncovered	(82,149)	81,180	(82,034)	90,643	94,519	91,968
Loans and Leases Receivable, Net Reported Amount, Covered and Not Covered	11,107,956		4,230,318	4,329,043
Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	5,601,020		2,795,998
Loans And Leases Net Of Discounts Covered	359,160		371,134
Loans and Leases Receivable Allowance Covered And Noncovered	22,276			31,804
Loans and Leases Receivable, Net Amount			2,422,107
Real Estate Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	310,534		219,517
Loans And Leases Net Of Discounts Covered	10,035		10,427
Loans and Leases Receivable Allowance Covered And Noncovered	4,302			3,432
Loans and Leases Receivable, Net Amount			207,779
Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	5,225,694		1,242,750
Loans And Leases Net Of Discounts Covered	28,939		974
Loans and Leases Receivable Allowance Covered And Noncovered	35,530			26,343
Loans and Leases Receivable, Net Amount			1,244,785
Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	63,276		55,070
Loans And Leases Net Of Discounts Covered	337		261
Loans and Leases Receivable Allowance Covered And Noncovered	3,415			1,667
Loans and Leases Receivable, Net Amount			54,885
NonCovered [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	10,791,669		3,929,556	3,926,230
Loans held for investment, net	10,791,669		3,929,556
Loans and Leases Receivable, Deferred Income	(10,384)		(983)
Loans and Leases Receivable, Allowance	(65,523)	(59,980)	(60,241)	(63,246)	(65,216)	(65,899)
Loans and Leases Receivable, Net Amount, Other	10,726,146
Loans and Leases Receivable, Net Amount	10,791,669		3,869,315
NonCovered [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	5,236,452		2,422,107	2,559,639
Loans and Leases Receivable Allowance Covered And Noncovered	22,276	24,352	26,078	31,804	37,265	38,700
Loans and Leases Receivable, Net Amount	5,236,452
NonCovered [Member] | Real Estate Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	298,477		207,779	197,776
Loans and Leases Receivable Allowance Covered And Noncovered	4,302	4,103	4,298	3,432	3,300	3,221
Loans and Leases Receivable, Net Amount	298,477
NonCovered [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	5,193,735		1,244,785	1,140,219
Loans and Leases Receivable Allowance Covered And Noncovered	35,530	27,740	26,921	26,343	23,157	22,252
Loans and Leases Receivable, Net Amount	5,193,735
NonCovered [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross			54,885	28,596
Loans and Leases Receivable Allowance Covered And Noncovered	3,415	3,785	2,944	1,667	1,494	1,726
Loans and Leases Receivable, Net Amount	63,005
Purchased Credit Impaired Loans and Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	398,436		382,796
Loans and Leases Receivable, Gross, Carrying Amount, Covered	436,495		428,251	494,389
Loans And Leases Net Of Discounts Covered	398,471		382,796
Loans held for investment, net	398,436
Loans and Leases Receivable Net Of Deferred Income Covered			382,796
Loans and Leases Receivable, Net Reported Amount, Covered	398,436		361,003
Loans and Leases Receivable, Deferred Income			0
Loans and Leases Receivable, Allowance, Covered	(16,626)	(21,200)	(21,793)	(27,397)	(29,303)	(26,069)
Loans and Leases Receivable, Net Amount, Other	381,810
Purchased Credit Impaired Loans and Leases [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	395,500		412,791
Loans and Leases Receivable, Net Amount	359,130		371,134
Purchased Credit Impaired Loans and Leases [Member] | Real Estate Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	10,763		12,015
Loans and Leases Receivable, Net Amount	10,030		10,427
Purchased Credit Impaired Loans and Leases [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	29,824		3,021
Loans and Leases Receivable, Net Amount	28,940		974
Purchased Credit Impaired Loans and Leases [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	408		424
Loans and Leases Receivable, Net Amount	336		261
Gross Gross [Member] | NonCovered [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	10,802,053		3,930,539
Gross Gross [Member] | NonCovered [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	5,241,860		2,424,864
Gross Gross [Member] | NonCovered [Member] | Real Estate Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	300,499		209,090
Gross Gross [Member] | NonCovered [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	5,196,755		1,241,776
Gross Gross [Member] | NonCovered [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	$ 62,939		$ 54,809