Loans Receivable and Allowance For Credit Losses - Allowance for Credit Losses Roll Forward (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Loans and Leases Receivable, Allowance [Abstract]
Individually evaluated for impairment	$ 103,950	$ 126,257
Collectively evaluated for impairment	7,353,869	6,126,977
Total loans receivable, gross	7,457,819	6,253,234
Individually evaluated for impairment	6,917	8,463
Collectively evaluated for impairment	130,377	145,882
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses - beginning balance	154,345	177,458	247,056
Provisions	(5,200)	7,500	28,500
Charge-offs	28,361	58,737	129,169
Recoveries	16,510	28,124	31,071
Allowance for loan losses - ending balance	137,294	154,345	177,458
Allowance for unfunded credit commitments - beginning balance	8,002	10,029	10,707
Provisions	5,200	2,500	1,500
Charge-offs	2,081	4,527	2,178
Recoveries	0	0	0
Allowance for unfunded credit commitments - ending balance	11,121	8,002	10,029
Total credit allowance	148,415	162,347	187,487
Residential real estate [Member]
Loans and Leases Receivable, Allowance [Abstract]
Individually evaluated for impairment	7,924	9,134
Collectively evaluated for impairment	1,111,650	797,588
Total loans receivable, gross	1,119,574	806,722
Individually evaluated for impairment	2,968	365
Collectively evaluated for impairment	11,277	19,482
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses - beginning balance	19,847	15,197	17,307
Provisions	(2,924)	8,778	15,024
Charge-offs	4,167	5,203	18,553
Recoveries	1,489	1,075	1,419
Allowance for loan losses - ending balance	14,245	19,847	15,197
Allowance for unfunded credit commitments - beginning balance	2,230	3,828	3,189
Provisions	3,171	2,929	2,817
Charge-offs	2,081	4,527	2,178
Recoveries	0	0	0
Allowance for unfunded credit commitments - ending balance	3,320	2,230	3,828
Total credit allowance	17,565	22,077	19,025
Commercial real estate
Loans and Leases Receivable, Allowance [Abstract]
Individually evaluated for impairment	58,232	68,317
Collectively evaluated for impairment	3,284,663	2,806,484
Total loans receivable, gross	3,342,895	2,874,801
Individually evaluated for impairment	952	3,182
Collectively evaluated for impairment	40,201	44,912
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses - beginning balance	48,094	91,722	124,907
Provisions	(4,639)	(33,184)	19,129
Charge-offs	11,722	27,385	73,379
Recoveries	9,420	16,941	21,065
Allowance for loan losses - ending balance	41,153	48,094	91,722
Allowance for unfunded credit commitments - beginning balance	405	2,321	4,157
Provisions	593	(1,916)	(1,836)
Charge-offs	0	0	0
Recoveries	0	0	0
Allowance for unfunded credit commitments - ending balance	998	405	2,321
Total credit allowance	42,151	48,499	94,043
Commercial [Member]
Loans and Leases Receivable, Allowance [Abstract]
Individually evaluated for impairment	37,794	48,312
Collectively evaluated for impairment	2,135,488	1,768,778
Total loans receivable, gross	2,173,282	1,817,090
Individually evaluated for impairment	2,842	4,916
Collectively evaluated for impairment	39,272	36,958
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses - beginning balance	41,874	38,046	56,951
Provisions	2,614	12,189	2,708
Charge-offs	6,572	17,005	28,369
Recoveries	4,198	8,644	6,756
Allowance for loan losses - ending balance	42,114	41,874	38,046
Allowance for unfunded credit commitments - beginning balance	2,806	1,796	1,515
Provisions	326	1,010	281
Charge-offs	0	0	0
Recoveries	0	0	0
Allowance for unfunded credit commitments - ending balance	3,132	2,806	1,796
Total credit allowance	45,246	44,680	39,842
Consumer [Member]
Loans and Leases Receivable, Allowance [Abstract]
Individually evaluated for impairment	0	494
Collectively evaluated for impairment	822,068	754,127
Total loans receivable, gross	822,068	754,621
Individually evaluated for impairment	155	0
Collectively evaluated for impairment	27,423	25,602
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses - beginning balance	25,602	13,427	14,645
Provisions	6,473	19,855	5,819
Charge-offs	5,900	9,144	8,868
Recoveries	1,403	1,464	1,831
Allowance for loan losses - ending balance	27,578	25,602	13,427
Allowance for unfunded credit commitments - beginning balance	2,118	1,787	817
Provisions	1,481	331	970
Charge-offs	0	0	0
Recoveries	0	0	0
Allowance for unfunded credit commitments - ending balance	3,599	2,118	1,787
Total credit allowance	31,177	27,720	15,214
Unallocated
Loans and Leases Receivable, Allowance [Abstract]
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	0	0
Total loans receivable, gross	0	0
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	12,204	18,928
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses - beginning balance	18,928	19,066	33,246
Provisions	(6,724)	(138)	(14,180)
Charge-offs	0	0	0
Recoveries	0	0	0
Allowance for loan losses - ending balance	12,204	18,928	19,066
Allowance for unfunded credit commitments - beginning balance	443	297	1,029
Provisions	(371)	146	(732)
Charge-offs	0	0	0
Recoveries	0	0	0
Allowance for unfunded credit commitments - ending balance	72	443	297
Total credit allowance	$ 12,276	$ 19,371	$ 19,363