Loans (Financing Receivables Credit Quality Indicators) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015
Originated Loans
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	$ 14,665,631	$ 14,118,505	$ 13,355,912
Originated Loans | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	5,882,994	5,793,408	5,471,363
Originated Loans | Real Estate Loan
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	2,035,498	2,077,344	2,138,372
Originated Loans | Construction Loans
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	705,340	645,337	586,895
Originated Loans | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	508,534	491,741	436,702
Originated Loans | Commercial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	9,132,366	9,007,830	8,633,332
Originated Loans | Grade One | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	75,818	60,440	65,856
Originated Loans | Grade One | Real Estate Loan
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	742	773	807
Originated Loans | Grade One | Construction Loans
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Originated Loans | Grade One | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	12,001	12,732	14,688
Originated Loans | Grade One | Commercial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	88,561	73,945	81,351
Originated Loans | Grade Two | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	416,677	353,581	206,384
Originated Loans | Grade Two | Real Estate Loan
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	806	831	1,166
Originated Loans | Grade Two | Construction Loans
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Originated Loans | Grade Two | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	49,953	69,258	29,564
Originated Loans | Grade Two | Commercial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	467,436	423,670	237,114
Originated Loans | Grade Three | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	1,267,423	1,371,850	1,417,295
Originated Loans | Grade Three | Real Estate Loan
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	294,396	319,987	367,457
Originated Loans | Grade Three | Construction Loans
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	46,114	59,182	55,889
Originated Loans | Grade Three | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	87,346	49,956	65,664
Originated Loans | Grade Three | Commercial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	1,695,279	1,800,975	1,906,305
Originated Loans | Grade Four | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	3,886,039	3,756,333	3,567,387
Originated Loans | Grade Four | Real Estate Loan
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	1,697,194	1,697,261	1,715,998
Originated Loans | Grade Four | Construction Loans
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	609,659	569,098	529,517
Originated Loans | Grade Four | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	325,346	344,763	321,268
Originated Loans | Grade Four | Commercial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	6,518,238	6,367,455	6,134,170
Originated Loans | Grade Five | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	73,989	124,140	98,137
Originated Loans | Grade Five | Real Estate Loan
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	13,929	18,388	25,466
Originated Loans | Grade Five | Construction Loans
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	31,744	7,193	360
Originated Loans | Grade Five | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	22,830	7,858	2,956
Originated Loans | Grade Five | Commercial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	142,492	157,579	126,919
Originated Loans | Grade Six | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	154,707	124,483	112,661
Originated Loans | Grade Six | Real Estate Loan
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	28,431	40,105	27,478
Originated Loans | Grade Six | Construction Loans
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	17,823	9,864	1,129
Originated Loans | Grade Six | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	11,058	7,174	2,562
Originated Loans | Grade Six | Commercial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	212,019	181,626	143,830
Originated Loans | Grade Seven | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	8,341	2,581	3,643
Originated Loans | Grade Seven | Real Estate Loan
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	(1)	0
Originated Loans | Grade Seven | Construction Loans
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Originated Loans | Grade Seven | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Originated Loans | Grade Seven | Commercial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	8,341	2,580	3,643
Acquired Loans
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	1,488,636	1,743,071	2,095,684
Acquired Loans | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	181,503	240,145	337,423
Acquired Loans | Real Estate Loan
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	368,800	430,891	533,945
Acquired Loans | Construction Loans
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	4,111	6,113	6,230
Acquired Loans | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans | Commercial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	554,414	677,149	877,598
Acquired Loans | Grade One | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	346	1,061
Acquired Loans | Grade One | Real Estate Loan
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans | Grade One | Construction Loans
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans | Grade One | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans | Grade One | Commercial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	346	1,061
Acquired Loans | Grade Two | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans | Grade Two | Real Estate Loan
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans | Grade Two | Construction Loans
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans | Grade Two | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans | Grade Two | Commercial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans | Grade Three | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	5,994	15,548	17,338
Acquired Loans | Grade Three | Real Estate Loan
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	24,244	27,387	27,190
Acquired Loans | Grade Three | Construction Loans
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans | Grade Three | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans | Grade Three | Commercial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	30,238	42,935	44,528
Acquired Loans | Grade Four | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	140,944	200,736	289,027
Acquired Loans | Grade Four | Real Estate Loan
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	303,228	361,518	453,830
Acquired Loans | Grade Four | Construction Loans
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	3,698	5,380	5,536
Acquired Loans | Grade Four | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans | Grade Four | Commercial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	447,870	567,634	748,393
Acquired Loans | Grade Five | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	27,053	11,735	13,283
Acquired Loans | Grade Five | Real Estate Loan
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	11,607	12,546	16,815
Acquired Loans | Grade Five | Construction Loans
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans | Grade Five | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans | Grade Five | Commercial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	38,660	24,281	30,098
Acquired Loans | Grade Six | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	7,512	11,780	16,714
Acquired Loans | Grade Six | Real Estate Loan
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	29,721	29,440	36,110
Acquired Loans | Grade Six | Construction Loans
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	413	733	694
Acquired Loans | Grade Six | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans | Grade Six | Commercial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	37,646	41,953	53,518
Acquired Loans | Grade Seven | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans | Grade Seven | Real Estate Loan
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans | Grade Seven | Construction Loans
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans | Grade Seven | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Acquired Loans | Grade Seven | Commercial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Covered Loans
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	180,784	205,422	241,694
Covered Loans | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	31,274	35,466	38,137
Covered Loans | Real Estate Loan
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	79,888	87,774	101,809
Covered Loans | Construction Loans
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	4,631	5,869	5,875
Covered Loans | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Covered Loans | Commercial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	115,793	129,109	145,821
Covered Loans | Grade One | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Covered Loans | Grade One | Real Estate Loan
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Covered Loans | Grade One | Construction Loans
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 One | Commercial
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	0	1,072	1,129
Covered Loans | Grade Two | Real Estate Loan
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Covered Loans | Grade Two | Construction Loans
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 Two | Commercial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	1,072	1,129
Covered Loans | Grade Three | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Covered Loans | Grade Three | Real Estate Loan
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	7,040	7,004	0
Covered Loans | Grade Three | Construction Loans
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 Three | Commercial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	7,040	7,004	0
Covered Loans | Grade Four | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	27,834	31,637	33,992
Covered Loans | Grade Four | Real Estate Loan
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	45,520	49,917	65,906
Covered Loans | Grade Four | Construction Loans
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	819	817
Covered Loans | Grade Four | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Covered Loans | Grade Four | Commercial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	73,354	82,373	100,715
Covered Loans | Grade Five | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	295	0
Covered Loans | Grade Five | Real Estate Loan
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	625
Covered Loans | Grade Five | Construction Loans
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Covered Loans | Grade Five | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Covered Loans | Grade Five | Commercial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	295	625
Covered Loans | Grade Six | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	3,440	2,462	3,016
Covered Loans | Grade Six | Real Estate Loan
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	27,328	30,853	35,278
Covered Loans | Grade Six | Construction Loans
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	4,631	5,050	5,058
Covered Loans | Grade Six | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Covered Loans | Grade Six | Commercial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	35,399	38,365	43,352
Covered Loans | Grade Seven | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Covered Loans | Grade Seven | Real Estate Loan
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Covered Loans | Grade Seven | Construction Loans
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Covered Loans | Grade Seven | Commercial Leases Financing Receivable
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	0	0	0
Covered Loans | Grade Seven | Commercial
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Net	$ 0	$ 0	$ 0