Loans (Past Due Financing Receivables Table) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Financing Receivable, Recorded Investment, Past Due [Line Items]
Consumer Loans Guaranteed by Government	$ 2,400,000	$ 2,100,000
FDIC Indemnification Asset	22,033,000	61,827,000
Originated Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	33,099,000	52,585,000
Days Past Due 60 to 89	10,116,000	10,926,000
Days Past Due more than 90	26,329,000	35,888,000
Total Past Due	69,544,000	99,399,000
Current	12,424,268,000	10,113,988,000
Total Loans	12,493,812,000	10,213,387,000	8,731,659,000
More than 90 days Past Due and Accruing	12,156,000	11,176,000
Nonaccrual Loans	34,617,000	42,203,000
Acquired Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	25,656,000	32,793,000
Days Past Due 60 to 89	9,432,000	13,578,000
Days Past Due more than 90	40,268,000	45,133,000
Total Past Due	75,356,000	91,504,000
Current	2,403,824,000	3,404,111,000
Total Loans	2,479,180,000	3,495,615,000
More than 90 days Past Due and Accruing	3,471,000	4,148,000
Nonaccrual Loans	8,056,000	4,007,000
Covered Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	7,915,000	13,922,000
Days Past Due 60 to 89	2,478,000	9,881,000
Days Past Due more than 90	66,803,000	143,238,000
Total Past Due	77,196,000	167,041,000
Current	253,926,000	363,102,000
Total Loans	331,122,000	530,143,000
Commercial and Industrial Financing Receivable | Originated Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	2,212,000	8,941,000
Days Past Due 60 to 89	1,162,000	994,000
Days Past Due more than 90	2,670,000	10,622,000
Total Past Due	6,044,000	20,557,000
Current	5,169,157,000	4,119,010,000
Total Loans	5,175,201,000	4,139,567,000	3,306,526,000
More than 90 days Past Due and Accruing	1,547,000	151,000
Nonaccrual Loans	6,114,000	11,323,000
Commercial and Industrial Financing Receivable | Acquired Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	92,000	1,295,000
Days Past Due 60 to 89	234,000	862,000
Days Past Due more than 90	4,791,000	3,744,000
Total Past Due	5,117,000	5,901,000
Current	444,137,000	788,178,000
Total Loans	449,254,000	794,079,000
More than 90 days Past Due and Accruing	0	40,000
Nonaccrual Loans	787,000	795,000
Commercial and Industrial Financing Receivable | Covered Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	58,000	836,000
Days Past Due 60 to 89	0	1,489,000
Days Past Due more than 90	6,041,000	12,957,000
Total Past Due	6,099,000	15,282,000
Current	42,738,000	60,955,000
Total Loans	48,837,000	76,237,000
Commercial Real Estate Other Receivable | Originated Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	2,155,000	4,507,000
Days Past Due 60 to 89	1,460,000	2,400,000
Days Past Due more than 90	8,864,000	9,688,000
Total Past Due	12,479,000	16,595,000
Current	2,104,639,000	2,153,192,000
Total Loans	2,117,118,000	2,169,787,000
More than 90 days Past Due and Accruing	1,696,000	460,000
Nonaccrual Loans	11,033,000	14,229,000
Commercial Real Estate Other Receivable | Acquired Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	3,479,000	5,603,000
Days Past Due 60 to 89	3,398,000	5,281,000
Days Past Due more than 90	23,509,000	26,366,000
Total Past Due	30,386,000	37,250,000
Current	600,288,000	881,395,000
Total Loans	630,674,000	918,645,000
More than 90 days Past Due and Accruing	44,000	403,000
Nonaccrual Loans	4,171,000	651,000
Commercial Real Estate Other Receivable | Covered Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	234,000	2,855,000
Days Past Due 60 to 89	1,517,000	3,443,000
Days Past Due more than 90	47,233,000	103,077,000
Total Past Due	48,984,000	109,375,000
Current	104,524,000	164,219,000
Total Loans	153,508,000	273,594,000
Commercial Construction Financing Receivable [Member] | Acquired Loans
Summary of loans by portfolio type
Days Past Due 30 to 59		2,675,000
Days Past Due 60 to 89		0
Days Past Due more than 90		0
Total Past Due		2,675,000
Current		10,571,000
Total Loans		13,246,000
More than 90 days Past Due and Accruing		0
Nonaccrual Loans		0
Commercial Real Estate Construction Financing Receivable | Originated Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	0	351,000
Days Past Due 60 to 89	0	21,000
Days Past Due more than 90	0	66,000
Total Past Due	0	438,000
Current	537,766,000	338,487,000
Total Loans	537,766,000	338,925,000
More than 90 days Past Due and Accruing	0	0
Nonaccrual Loans	0	122,000
Commercial Real Estate Construction Financing Receivable | Acquired Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	0
Days Past Due 60 to 89	0
Days Past Due more than 90	685,000
Total Past Due	685,000
Current	6,286,000
Total Loans	6,971,000	13,246,000
More than 90 days Past Due and Accruing	0
Nonaccrual Loans	0
Commercial Real Estate Construction Financing Receivable | Covered Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	0	2,191,000
Days Past Due 60 to 89	0	1,917,000
Days Past Due more than 90	6,064,000	20,388,000
Total Past Due	6,064,000	24,496,000
Current	3,198,000	1,533,000
Total Loans	9,262,000	26,029,000
Commercial Leases Financing Receivable | Originated Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	0	902,000
Days Past Due 60 to 89	0	0
Days Past Due more than 90	0	0
Total Past Due	0	902,000
Current	370,179,000	238,649,000
Total Loans	370,179,000	239,551,000
More than 90 days Past Due and Accruing	0	0
Nonaccrual Loans	0	0
Commercial Leases Financing Receivable | Acquired Loans
Summary of loans by portfolio type
Total Loans	0	0
Commercial Leases Financing Receivable | Covered Loans
Summary of loans by portfolio type
Total Loans	0	0
Consumer Installment Financing Receivable | Originated Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	14,621,000	15,433,000
Days Past Due 60 to 89	3,647,000	4,050,000
Days Past Due more than 90	4,716,000	4,462,000
Total Past Due	22,984,000	23,945,000
Current	2,370,467,000	1,703,980,000
Total Loans	2,393,451,000	1,727,925,000
More than 90 days Past Due and Accruing	3,695,000	3,735,000
Nonaccrual Loans	3,268,000	3,681,000
Consumer Installment Financing Receivable | Acquired Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	6,204,000	14,528,000
Days Past Due 60 to 89	2,029,000	4,076,000
Days Past Due more than 90	1,861,000	3,354,000
Total Past Due	10,094,000	21,958,000
Current	754,074,000	982,611,000
Total Loans	764,168,000	1,004,569,000
More than 90 days Past Due and Accruing	615,000	2,263,000
Nonaccrual Loans	1,218,000	679,000
Consumer Installment Financing Receivable | Covered Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	23,000	33,000
Days Past Due 60 to 89	0	0
Days Past Due more than 90	34,000	0
Total Past Due	57,000	33,000
Current	4,817,000	6,130,000
Total Loans	4,874,000	6,163,000
Consumer Home Equity Lines Financing Receivable | Originated Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	1,357,000	1,864,000
Days Past Due 60 to 89	587,000	918,000
Days Past Due more than 90	1,206,000	965,000
Total Past Due	3,150,000	3,747,000
Current	1,107,186,000	916,319,000
Total Loans	1,110,336,000	920,066,000
More than 90 days Past Due and Accruing	569,000	418,000
Nonaccrual Loans	1,654,000	1,819,000
Consumer Home Equity Lines Financing Receivable | Acquired Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	2,819,000	4,774,000
Days Past Due 60 to 89	2,123,000	1,933,000
Days Past Due more than 90	2,333,000	3,606,000
Total Past Due	7,275,000	10,313,000
Current	226,354,000	284,111,000
Total Loans	233,629,000	294,424,000
More than 90 days Past Due and Accruing	1,519,000	1,039,000
Nonaccrual Loans	631,000	1,300,000
Consumer Home Equity Lines Financing Receivable | Covered Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	1,395,000	544,000
Days Past Due 60 to 89	870,000	1,467,000
Days Past Due more than 90	3,859,000	1,651,000
Total Past Due	6,124,000	3,662,000
Current	67,241,000	93,780,000
Total Loans	73,365,000	97,442,000
Consumer Credit Card Financing Receivable | Originated Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	668,000	729,000
Days Past Due 60 to 89	516,000	471,000
Days Past Due more than 90	860,000	735,000
Total Past Due	2,044,000	1,935,000
Current	162,434,000	146,378,000
Total Loans	164,478,000	148,313,000
More than 90 days Past Due and Accruing	407,000	404,000
Nonaccrual Loans	596,000	558,000
Consumer Residential Mortgages Financing Receivable | Originated Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	12,086,000	19,858,000
Days Past Due 60 to 89	2,744,000	2,072,000
Days Past Due more than 90	8,013,000	9,350,000
Total Past Due	22,843,000	31,280,000
Current	602,440,000	497,973,000
Total Loans	625,283,000	529,253,000
More than 90 days Past Due and Accruing	4,242,000	6,008,000
Nonaccrual Loans	11,952,000	10,471,000
Consumer Residential Mortgages Financing Receivable | Acquired Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	13,062,000	3,918,000
Days Past Due 60 to 89	1,648,000	1,426,000
Days Past Due more than 90	7,089,000	8,063,000
Total Past Due	21,799,000	13,407,000
Current	372,685,000	457,245,000
Total Loans	394,484,000	470,652,000
More than 90 days Past Due and Accruing	1,293,000	403,000
Nonaccrual Loans	1,249,000	582,000
Consumer Residential Mortgages Financing Receivable | Covered Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	6,205,000	7,463,000
Days Past Due 60 to 89	91,000	1,565,000
Days Past Due more than 90	3,572,000	5,165,000
Total Past Due	9,868,000	14,193,000
Current	31,408,000	36,485,000
Total Loans	$ 41,276,000	$ 50,678,000