Allowance for Loan and Lease Loss and Credit Quality (Non-Accrual Loans And Loans Past Due) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and Accruing	$ 10,416,000	$ 7,512,000
Total Past Due	30,904,000	32,171,000
Nonaccrual	40,246,000	52,041,000
Current	15,477,807,000	15,243,520,000
Total loans and leases, net of deferred fees and costs	15,548,957,000	15,327,732,000	7,763,691,000
Purchased impaired non-covered loans	521,100,000	562,900,000
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans and leases, net of deferred fees and costs	8,964,979,000		4,601,659,000
Non-owner Occupied Term [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and Accruing	2,425,000	283,000
Total Past Due	3,497,000	735,000
Nonaccrual	6,974,000	8,957,000
Current	3,293,158,000	3,280,918,000
Total loans and leases, net of deferred fees and costs	3,303,629,000	3,290,610,000
Owner Occupied Term [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and Accruing	0	0
Total Past Due	5,385,000	2,651,000
Nonaccrual	9,219,000	8,292,000
Current	2,562,880,000	2,622,921,000
Total loans and leases, net of deferred fees and costs	2,577,484,000	2,633,864,000
Multifamily [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and Accruing	0	0
Total Past Due	420,000	512,000
Nonaccrual	0	300,000
Current	2,763,983,000	2,637,806,000
Total loans and leases, net of deferred fees and costs	2,764,403,000	2,638,618,000
Construction & Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and Accruing	0	0
Total Past Due	0	1,091,000
Nonaccrual	0	0
Current	238,303,000	257,631,000
Total loans and leases, net of deferred fees and costs	238,303,000	258,722,000
Residential Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and Accruing	0	0
Total Past Due	0	6,155,000
Nonaccrual	0	0
Current	81,160,000	75,691,000
Total loans and leases, net of deferred fees and costs	81,160,000	81,846,000
Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans and leases, net of deferred fees and costs	2,975,349,000		2,149,482,000
Term [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and Accruing	21,000	3,000
Total Past Due	1,132,000	1,343,000
Nonaccrual	17,981,000	19,097,000
Current	1,109,873,000	1,082,547,000
Total loans and leases, net of deferred fees and costs	1,128,986,000	1,102,987,000
LOC & Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and Accruing	103,000	1,223,000
Total Past Due	1,694,000	4,015,000
Nonaccrual	1,611,000	8,825,000
Current	1,272,566,000	1,309,882,000
Total loans and leases, net of deferred fees and costs	1,275,871,000	1,322,722,000
Leases and Equipment Finance [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and Accruing	0	695,000
Total Past Due	3,901,000	3,872,000
Nonaccrual	3,358,000	5,084,000
Current	563,233,000	514,158,000
Total loans and leases, net of deferred fees and costs	570,492,000	523,114,000
Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans and leases, net of deferred fees and costs	3,193,594,000		960,336,000
Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and Accruing	6,874,000	4,289,000
Total Past Due	8,699,000	5,521,000
Nonaccrual	636,000	655,000
Current	2,320,990,000	2,227,559,000
Total loans and leases, net of deferred fees and costs	2,330,325,000	2,233,735,000
Home Equity Loans & Lines [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and Accruing	731,000	749,000
Total Past Due	3,656,000	3,375,000
Nonaccrual	433,000	615,000
Current	859,180,000	848,488,000
Total loans and leases, net of deferred fees and costs	863,269,000	852,478,000
Consumer & Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and Accruing	262,000	270,000
Total Past Due	2,520,000	2,901,000
Nonaccrual	34,000	216,000
Current	412,481,000	385,919,000
Total loans and leases, net of deferred fees and costs	415,035,000	389,036,000	52,214,000
Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	12,475,000	18,284,000
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-owner Occupied Term [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	487,000	452,000
Financing Receivables, 30 to 59 Days Past Due [Member] | Owner Occupied Term [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,599,000	2,304,000
Financing Receivables, 30 to 59 Days Past Due [Member] | Multifamily [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	420,000	0
Financing Receivables, 30 to 59 Days Past Due [Member] | Construction & Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	1,091,000
Financing Receivables, 30 to 59 Days Past Due [Member] | Residential Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	6,155,000
Financing Receivables, 30 to 59 Days Past Due [Member] | Term [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,108,000	1,098,000
Financing Receivables, 30 to 59 Days Past Due [Member] | LOC & Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	927,000	1,637,000
Financing Receivables, 30 to 59 Days Past Due [Member] | Leases and Equipment Finance [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,349,000	1,482,000
Financing Receivables, 30 to 59 Days Past Due [Member] | Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,485,000	8,000
Financing Receivables, 30 to 59 Days Past Due [Member] | Home Equity Loans & Lines [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,471,000	1,924,000
Financing Receivables, 30 to 59 Days Past Due [Member] | Consumer & Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,629,000	2,133,000
Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	8,013,000	6,375,000
Financing Receivables, 60 to 89 Days Past Due [Member] | Non-owner Occupied Term [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	585,000	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Owner Occupied Term [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,786,000	347,000
Financing Receivables, 60 to 89 Days Past Due [Member] | Multifamily [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	512,000
Financing Receivables, 60 to 89 Days Past Due [Member] | Construction & Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Residential Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Term [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	3,000	242,000
Financing Receivables, 60 to 89 Days Past Due [Member] | LOC & Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	664,000	1,155,000
Financing Receivables, 60 to 89 Days Past Due [Member] | Leases and Equipment Finance [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,552,000	1,695,000
Financing Receivables, 60 to 89 Days Past Due [Member] | Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	340,000	1,224,000
Financing Receivables, 60 to 89 Days Past Due [Member] | Home Equity Loans & Lines [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,454,000	702,000
Financing Receivables, 60 to 89 Days Past Due [Member] | Consumer & Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 629,000	$ 498,000