Allowance for Loan Losses (Troubled Debt Restructuring on Financing Receivables) (Details) $ in Thousands	Mar. 31, 2016 USD ($) loans	Dec. 31, 2015 USD ($) loans	Mar. 31, 2015 USD ($)
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	2,371	2,402	2,509
Recorded Investment	$ 151,764	$ 160,928	$ 135,631
Unpaid Principal Balance	$ 156,734	$ 165,694	$ 178,117
Originated Loans
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	2,034	2,054	2,150
Recorded Investment	$ 113,981	$ 116,364	$ 89,150
Unpaid Principal Balance	$ 119,889	$ 122,044	$ 104,823
Acquired Loans
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	257	262	247
Recorded Investment	$ 14,400	$ 19,518	$ 13,146
Unpaid Principal Balance	$ 15,060	$ 20,026	13,692
Covered Consumer Loans
Financing Receivable, Modifications [Line Items]
Number of contracts at period end | loans	80	86
Recorded Investment	$ 23,383	$ 25,046	$ 9,094
Unpaid Principal Balance	$ 21,785	$ 23,624
Covered TDR Loans
Financing Receivable, Modifications [Line Items]
Number of contracts at period end			112
Recorded Investment			$ 33,335
Unpaid Principal Balance			$ 59,602
Commercial and Industrial
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	27	27	56
Recorded Investment	$ 28,160	$ 40,698	$ 16,925
Unpaid Principal Balance	$ 28,980	$ 41,351	$ 25,024
Commercial and Industrial | Originated Loans
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	27	26	47
Recorded Investment	$ 28,160	$ 33,087	$ 16,923
Unpaid Principal Balance	$ 28,980	$ 33,740	$ 23,666
Commercial and Industrial | Acquired Loans
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	0	1	1
Recorded Investment	$ 0	$ 7,611	$ 2
Unpaid Principal Balance	$ 0	$ 7,611	$ 3
Commercial and Industrial | Covered Loans Commercial
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	0	0	8
Recorded Investment	$ 0	$ 0	$ 0
Unpaid Principal Balance	$ 0	$ 0	$ 1,355
Commercial Real Estate
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	30	30	91
Recorded Investment	$ 30,876	$ 29,645	$ 38,424
Unpaid Principal Balance	$ 31,434	$ 30,171	$ 59,556
Commercial Real Estate | Originated Loans
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	22	24	64
Recorded Investment	$ 14,175	$ 14,671	$ 12,076
Unpaid Principal Balance	$ 16,141	$ 16,648	$ 17,325
Commercial Real Estate | Acquired Loans
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	5	3	3
Recorded Investment	$ 3,525	$ 918	$ 2,453
Unpaid Principal Balance	$ 3,827	$ 1,044	$ 2,635
Commercial Real Estate | Covered Loans Commercial
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	3	3	24
Recorded Investment	$ 13,176	$ 14,056	$ 23,895
Unpaid Principal Balance	$ 11,466	$ 12,479	$ 39,596
Commercial | Acquired Loans
Financing Receivable, Modifications [Line Items]
Number of contracts at period end			4
Recorded Investment			$ 2,455
Unpaid Principal Balance			$ 2,638
Construction Loans
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	1	1	40
Recorded Investment	$ 580	$ 593	$ 346
Unpaid Principal Balance	$ 677	$ 682	$ 9,552
Construction Loans | Originated Loans
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	0	0	31
Recorded Investment	$ 0	$ 0	$ 0
Unpaid Principal Balance	$ 0	$ 0	$ 0
Construction Loans | Acquired Loans
Financing Receivable, Modifications [Line Items]
Number of contracts at period end | loans	0
Recorded Investment	$ 0
Unpaid Principal Balance	$ 0
Construction Loans | Covered Loans Commercial
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	1	1	9
Recorded Investment	$ 580	$ 593	$ 346
Unpaid Principal Balance	$ 677	$ 682	$ 9,552
Commercial Loan
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	58	58	187
Recorded Investment	$ 59,616	$ 70,936	$ 55,695
Unpaid Principal Balance	$ 61,091	$ 72,204	$ 94,132
Commercial Loan | Originated Loans
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	49	50	142
Recorded Investment	$ 42,335	$ 47,758	$ 28,999
Unpaid Principal Balance	$ 45,121	$ 50,388	40,991
Commercial Loan | Acquired Loans
Financing Receivable, Modifications [Line Items]
Number of contracts at period end | loans	5	4
Recorded Investment	$ 3,525	$ 8,529	$ 2,455
Unpaid Principal Balance	$ 3,827	$ 8,655
Commercial Loan | Covered Loans Commercial
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	4	4	41
Recorded Investment	$ 13,756	$ 14,649	$ 24,241
Unpaid Principal Balance	$ 12,143	$ 13,161	50,503
Commercial Loan | Covered TDR Loans
Financing Receivable, Modifications [Line Items]
Recorded Investment			$ 24,241
Consumer Loan
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	2,313	2,344	2,322
Recorded Investment	$ 92,148	$ 89,992	$ 79,936
Unpaid Principal Balance	$ 95,643	$ 93,490	$ 83,985
Consumer Loan | Originated Loans
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	1,985	2,004	2,008
Recorded Investment	$ 71,646	$ 68,606	$ 60,151
Unpaid Principal Balance	$ 74,768	$ 71,656	$ 63,832
Consumer Loan | Acquired Loans
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	252	258	243
Recorded Investment	$ 10,875	$ 10,989	$ 10,691
Unpaid Principal Balance	$ 11,233	$ 11,371	$ 11,054
Consumer Loan | Covered Consumer Loans
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	76	82	71
Recorded Investment	$ 9,627	$ 10,397	$ 9,094
Unpaid Principal Balance	$ 9,642	$ 10,463	$ 9,099
Residential Mortgages
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	338	344	347
Recorded Investment	$ 25,155	$ 26,241	$ 27,193
Unpaid Principal Balance	$ 27,875	$ 28,923	$ 30,200
Residential Mortgages | Originated Loans
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	307	312	316
Recorded Investment	$ 23,105	$ 23,905	$ 24,822
Unpaid Principal Balance	$ 25,598	$ 26,359	$ 27,612
Residential Mortgages | Acquired Loans
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	31	31	30
Recorded Investment	$ 2,050	$ 2,154	$ 2,186
Unpaid Principal Balance	$ 2,277	$ 2,382	2,403
Residential Mortgages | Covered Consumer Loans
Financing Receivable, Modifications [Line Items]
Number of contracts at period end | loans	0	1
Recorded Investment	$ 0	$ 182	$ 185
Unpaid Principal Balance	$ 0	$ 182
Credit Card Receivable
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	201	212	230
Recorded Investment	$ 687	$ 717	$ 815
Unpaid Principal Balance	$ 687	$ 717	$ 815
Credit Card Receivable | Originated Loans
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	201	212	230
Recorded Investment	$ 687	$ 717	$ 815
Unpaid Principal Balance	$ 687	$ 717	$ 815
Home Equity Line of Credit
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	500	514	508
Recorded Investment	$ 24,855	$ 25,013	$ 23,851
Unpaid Principal Balance	$ 25,191	$ 25,389	$ 24,161
Home Equity Line of Credit | Originated Loans
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	253	257	276
Recorded Investment	$ 7,720	$ 7,080	$ 7,632
Unpaid Principal Balance	$ 7,977	$ 7,330	$ 7,877
Home Equity Line of Credit | Acquired Loans
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	171	176	162
Recorded Investment	$ 7,508	$ 7,718	$ 7,310
Unpaid Principal Balance	$ 7,572	$ 7,778	$ 7,370
Home Equity Line of Credit | Covered Consumer Loans
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	76	81	70
Recorded Investment	$ 9,627	$ 10,215	$ 8,909
Unpaid Principal Balance	$ 9,642	$ 10,281	$ 8,914
Residential Real Estate | Covered TDR Loans
Financing Receivable, Modifications [Line Items]
Number of contracts at period end			1
Recorded Investment			$ 185
Unpaid Principal Balance			$ 185
Installment
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	1,274	1,274	1,237
Recorded Investment	$ 41,451	$ 38,021	$ 28,077
Unpaid Principal Balance	$ 41,890	$ 38,461	$ 28,809
Installment | Originated Loans
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	1,224	1,223	1,186
Recorded Investment	$ 40,134	$ 36,904	$ 26,882
Unpaid Principal Balance	$ 40,506	$ 37,250	$ 27,528
Installment | Acquired Loans
Financing Receivable, Modifications [Line Items]
Number of contracts at period end	50	51	51
Recorded Investment	$ 1,317	$ 1,117	$ 1,195
Unpaid Principal Balance	$ 1,384	$ 1,211	$ 1,281