Loans Financing receivables credit quality indicators (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013
Covered Loans
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	$ 434,666	$ 530,143	$ 676,526
Covered Loans | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	56,423	76,237	85,931
Covered Loans | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	217,256	273,594	382,091
Covered Loans | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	19,101	26,029	37,685
Covered Loans | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Covered Loans | Grade One | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Covered Loans | Grade One | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Covered Loans | Grade One | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Covered Loans | Grade One | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Covered Loans | Grade Two | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	1,015	968	1,001
Covered Loans | Grade Two | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Covered Loans | Grade Two | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Covered Loans | Grade Two | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Covered Loans | Grade Three | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Covered Loans | Grade Three | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Covered Loans | Grade Three | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Covered Loans | Grade Three | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Covered Loans | Grade Four | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	38,892	41,115	44,148
Covered Loans | Grade Four | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	104,455	113,863	131,889
Covered Loans | Grade Four | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	707	601	556
Covered Loans | Grade Four | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Covered Loans | Grade Five | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	999	427	661
Covered Loans | Grade Five | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	3,984	6,219	24,255
Covered Loans | Grade Five | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	1,364
Covered Loans | Grade Five | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Covered Loans | Grade Six | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	15,517	31,621	38,065
Covered Loans | Grade Six | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	108,637	153,318	224,533
Covered Loans | Grade Six | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	18,045	23,208	33,856
Covered Loans | Grade Six | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Covered Loans | Grade Seven | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	2,106	2,056
Covered Loans | Grade Seven | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	180	194	1,414
Covered Loans | Grade Seven | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	349	2,220	1,909
Covered Loans | Grade Seven | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans Noncovered
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net		3,495,615	4,258,892
Acquired Loans Noncovered | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	660,261	794,079	1,160,344
Acquired Loans Noncovered | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	783,743	918,645	1,098,124
Acquired Loans Noncovered | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	13,899	13,246	16,775
Acquired Loans Noncovered | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans Noncovered | Grade One | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	700	0	0
Acquired Loans Noncovered | Grade One | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans Noncovered | Grade One | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans Noncovered | Grade One | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans Noncovered | Grade Two | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	1,741	107
Acquired Loans Noncovered | Grade Two | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	703	0
Acquired Loans Noncovered | Grade Two | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans Noncovered | Grade Two | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans Noncovered | Grade Three | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	35,608	79,634	24,511
Acquired Loans Noncovered | Grade Three | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	26,652	29,224	28,509
Acquired Loans Noncovered | Grade Three | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans Noncovered | Grade Three | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans Noncovered | Grade Four | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	553,293	643,495	1,050,350
Acquired Loans Noncovered | Grade Four | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	651,011	722,307	848,214
Acquired Loans Noncovered | Grade Four | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	13,899	13,246	15,558
Acquired Loans Noncovered | Grade Four | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans Noncovered | Grade Five | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	41,213	46,807	58,399
Acquired Loans Noncovered | Grade Five | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	50,267	93,499	125,154
Acquired Loans Noncovered | Grade Five | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	1,217
Acquired Loans Noncovered | Grade Five | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans Noncovered | Grade Six | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	29,447	22,402	26,977
Acquired Loans Noncovered | Grade Six | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	55,813	72,912	96,247
Acquired Loans Noncovered | Grade Six | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans Noncovered | Grade Six | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans Noncovered | Grade Seven | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans Noncovered | Grade Seven | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans Noncovered | Grade Seven | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans Noncovered | Grade Seven | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Legacy Loans | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	4,857,615
Legacy Loans | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	2,098,018
Legacy Loans | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	409,866
Legacy Loans | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	319,795
Legacy Loans | Grade One | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	33,855
Legacy Loans | Grade One | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0
Legacy Loans | Grade One | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0
Legacy Loans | Grade One | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	9,408
Legacy Loans | Grade Two | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	134,682
Legacy Loans | Grade Two | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	3,610
Legacy Loans | Grade Two | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0
Legacy Loans | Grade Two | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	10,971
Legacy Loans | Grade Three | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	1,100,807
Legacy Loans | Grade Three | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	290,652
Legacy Loans | Grade Three | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	36,954
Legacy Loans | Grade Three | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	55,648
Legacy Loans | Grade Four | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	3,439,210
Legacy Loans | Grade Four | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	1,725,808
Legacy Loans | Grade Four | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	371,488
Legacy Loans | Grade Four | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	236,324
Legacy Loans | Grade Five | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	100,776
Legacy Loans | Grade Five | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	29,382
Legacy Loans | Grade Five | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0
Legacy Loans | Grade Five | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	7,092
Legacy Loans | Grade Six | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	48,285
Legacy Loans | Grade Six | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	48,566
Legacy Loans | Grade Six | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	1,424
Legacy Loans | Grade Six | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	352
Legacy Loans | Grade Seven | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0
Legacy Loans | Grade Seven | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0
Legacy Loans | Grade Seven | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0
Legacy Loans | Grade Seven | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0
Originated Loans
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	11,467,193	10,213,387	9,132,625
Originated Loans | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	4,857,615	4,139,567	3,478,190
Originated Loans | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	2,098,018	2,169,787	2,214,857
Originated Loans | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net		338,925	304,765
Originated Loans | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	319,795	239,551	188,353
Originated Loans | Grade One | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net		34,909	40,185
Originated Loans | Grade One | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net		241	1,250
Originated Loans | Grade One | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net		0	0
Originated Loans | Grade One | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net		9,271	12,815
Originated Loans | Grade Two | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net		108,709	124,748
Originated Loans | Grade Two | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net		3,730	3,859
Originated Loans | Grade Two | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net		0	0
Originated Loans | Grade Two | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net		2,900	709
Originated Loans | Grade Three | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net		802,624	721,517
Originated Loans | Grade Three | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net		315,150	297,052
Originated Loans | Grade Three | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net		25,632	19,119
Originated Loans | Grade Three | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net		54,446	36,743
Originated Loans | Grade Four | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net		3,083,458	2,483,972
Originated Loans | Grade Four | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net		1,759,383	1,826,543
Originated Loans | Grade Four | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net		306,795	282,034
Originated Loans | Grade Four | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net		167,022	134,834
Originated Loans | Grade Five | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net		71,857	41,698
Originated Loans | Grade Five | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net		34,969	32,705
Originated Loans | Grade Five | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net		267	1,363
Originated Loans | Grade Five | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net		5,750	3,042
Originated Loans | Grade Six | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net		38,010	66,070
Originated Loans | Grade Six | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net		56,314	53,448
Originated Loans | Grade Six | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net		6,231	2,249
Originated Loans | Grade Six | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net		162	210
Originated Loans | Grade Seven | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net		0	0
Originated Loans | Grade Seven | Commercial Real Estate Other Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net		0	0
Originated Loans | Grade Seven | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net		0	0
Originated Loans | Grade Seven | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net		$ 0	$ 0