Loans, Allowance for Loan and Lease Losses, and Reserve for Off-Balance Sheet Credit Commitments (Details 5) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Jul. 02, 2012	Jun. 30, 2012
Recorded Investment
With no related allowance recorded	$ 95,999,000	$ 129,357,000	$ 95,999,000	$ 129,357,000	$ 119,511,000
With an allowance recorded	14,581,000	36,460,000	14,581,000	36,460,000	19,081,000
Total impaired loans	110,580,000	165,817,000	110,580,000	165,817,000	138,592,000
Unpaid Contractual Principal Balance
With no related allowance recorded	120,346,000	166,059,000	120,346,000	166,059,000	162,309,000
With an allowance recorded	16,666,000	49,464,000	16,666,000	49,464,000	20,293,000
Total impaired loans	137,012,000	215,523,000	137,012,000	215,523,000	182,602,000
Related Allowance
Total impaired loans	1,178,000	4,831,000	1,178,000	4,831,000	2,403,000
Average Recorded Investment
With no related allowance recorded	95,042,000	129,856,000	99,915,000	115,537,000
With an allowance recorded	19,513,000	39,944,000	22,970,000	44,281,000
Total impaired loans	114,555,000	169,800,000	122,885,000	159,818,000
Interest Income Recognized
With no related allowance recorded	1,617,000	323,000	4,116,000	728,000
With an allowance recorded	215,000	4,000	1,142,000	4,000
Total impaired loans	1,832,000	327,000	5,258,000	732,000
Minimum limit for nonperforming loans to be individually evaluated for impairment						1,000,000	500,000
Minimum limit for measuring impairment at the relationship level for borrowers with multiple loans exceeding $1,000,000						1,000,000
Outstanding loan amount of previously reported impaired loans under $1,000,000	6,100,000		6,100,000
Commercial
Recorded Investment
With no related allowance recorded	25,233,000	28,575,000	25,233,000	28,575,000	18,761,000
With an allowance recorded	7,494,000	6,156,000	7,494,000	6,156,000	7,516,000
Total impaired loans	32,727,000	34,731,000	32,727,000	34,731,000	26,277,000
Unpaid Contractual Principal Balance
With no related allowance recorded	25,488,000	39,624,000	25,488,000	39,624,000	24,135,000
With an allowance recorded	9,168,000	6,922,000	9,168,000	6,922,000	8,038,000
Total impaired loans	34,656,000	46,546,000	34,656,000	46,546,000	32,173,000
Related Allowance
Total impaired loans	344,000	1,167,000	344,000	1,167,000	952,000
Average Recorded Investment
With no related allowance recorded	26,255,000	30,476,000	22,584,000	24,732,000
With an allowance recorded	7,567,000	8,461,000	7,556,000	11,286,000
Total impaired loans	33,822,000	38,937,000	30,140,000	36,018,000
Interest Income Recognized
With no related allowance recorded	593,000		1,440,000
With an allowance recorded	156,000		513,000
Total impaired loans	749,000		1,953,000
Commercial real estate mortgages
Recorded Investment
With no related allowance recorded	33,133,000	40,825,000	33,133,000	40,825,000	42,882,000
With an allowance recorded	5,413,000	17,392,000	5,413,000	17,392,000	10,203,000
Total impaired loans	38,546,000	58,217,000	38,546,000	58,217,000	53,085,000
Unpaid Contractual Principal Balance
With no related allowance recorded	37,754,000	46,081,000	37,754,000	46,081,000	49,110,000
With an allowance recorded	5,810,000	18,962,000	5,810,000	18,962,000	10,783,000
Total impaired loans	43,564,000	65,043,000	43,564,000	65,043,000	59,893,000
Related Allowance
Total impaired loans	602,000	1,874,000	602,000	1,874,000	1,326,000
Average Recorded Investment
With no related allowance recorded	29,977,000	34,597,000	33,060,000	25,767,000
With an allowance recorded	10,262,000	17,257,000	11,018,000	13,406,000
Total impaired loans	40,239,000	51,854,000	44,078,000	39,173,000
Interest Income Recognized
With no related allowance recorded	440,000	34,000	1,102,000	158,000
With an allowance recorded	45,000		361,000
Total impaired loans	485,000	34,000	1,463,000	158,000
Residential mortgage
Recorded Investment
With no related allowance recorded	5,093,000	7,727,000	5,093,000	7,727,000	8,347,000
With an allowance recorded	1,674,000	3,615,000	1,674,000	3,615,000	463,000
Total impaired loans	6,767,000	11,342,000	6,767,000	11,342,000	8,810,000
Unpaid Contractual Principal Balance
With no related allowance recorded	5,573,000	8,581,000	5,573,000	8,581,000	9,194,000
With an allowance recorded	1,688,000	3,812,000	1,688,000	3,812,000	507,000
Total impaired loans	7,261,000	12,393,000	7,261,000	12,393,000	9,701,000
Related Allowance
Total impaired loans	232,000	185,000	232,000	185,000	9,000
Average Recorded Investment
With no related allowance recorded	5,689,000	7,907,000	6,922,000	8,057,000
With an allowance recorded	1,684,000	4,581,000	958,000	3,723,000
Total impaired loans	7,373,000	12,488,000	7,880,000	11,780,000
Interest Income Recognized
With no related allowance recorded	80,000	9,000	191,000	48,000
With an allowance recorded	14,000	4,000	55,000	4,000
Total impaired loans	94,000	13,000	246,000	52,000
Fixed
Recorded Investment
With no related allowance recorded	2,031,000	4,199,000	2,031,000	4,199,000	3,482,000
With an allowance recorded		2,229,000		2,229,000	463,000
Unpaid Contractual Principal Balance
With no related allowance recorded	2,155,000	4,613,000	2,155,000	4,613,000	3,757,000
With an allowance recorded		2,336,000		2,336,000	507,000
Related Allowance
Total impaired loans		181,000		181,000	9,000
Average Recorded Investment
With no related allowance recorded	2,019,000	3,014,000	2,860,000	3,047,000
With an allowance recorded		2,260,000	116,000	1,844,000
Interest Income Recognized
With no related allowance recorded	33,000		75,000
Variable
Recorded Investment
With no related allowance recorded	3,062,000	3,528,000	3,062,000	3,528,000	4,865,000
With an allowance recorded	1,674,000	1,386,000	1,674,000	1,386,000
Unpaid Contractual Principal Balance
With no related allowance recorded	3,418,000	3,968,000	3,418,000	3,968,000	5,437,000
With an allowance recorded	1,688,000	1,476,000	1,688,000	1,476,000
Related Allowance
Total impaired loans	232,000	4,000	232,000	4,000
Average Recorded Investment
With no related allowance recorded	3,670,000	4,893,000	4,062,000	5,010,000
With an allowance recorded	1,684,000	2,321,000	842,000	1,879,000
Interest Income Recognized
With no related allowance recorded	47,000	9,000	116,000	48,000
With an allowance recorded	14,000	4,000	55,000	4,000
Real estate construction
Recorded Investment
With no related allowance recorded	30,190,000	48,484,000	30,190,000	48,484,000	45,510,000
With an allowance recorded		8,098,000		8,098,000
Total impaired loans	30,190,000	56,582,000	30,190,000	56,582,000	45,510,000
Unpaid Contractual Principal Balance
With no related allowance recorded	48,156,000	66,476,000	48,156,000	66,476,000	74,283,000
With an allowance recorded		18,362,000		18,362,000
Total impaired loans	48,156,000	84,838,000	48,156,000	84,838,000	74,283,000
Related Allowance
Total impaired loans		1,467,000		1,467,000
Average Recorded Investment
With no related allowance recorded	30,318,000	53,124,000	34,410,000	51,952,000
With an allowance recorded		8,432,000	3,213,000	14,700,000
Total impaired loans	30,318,000	61,556,000	37,623,000	66,652,000
Interest Income Recognized
With no related allowance recorded	457,000	280,000	1,302,000	522,000
With an allowance recorded			213,000
Total impaired loans	457,000	280,000	1,515,000	522,000
Construction
Recorded Investment
With no related allowance recorded	16,259,000	29,446,000	16,259,000	29,446,000	19,762,000
Unpaid Contractual Principal Balance
With no related allowance recorded	21,064,000	42,870,000	21,064,000	42,870,000	33,267,000
Average Recorded Investment
With no related allowance recorded	16,262,000	34,137,000	17,904,000	29,189,000
Interest Income Recognized
With no related allowance recorded	233,000	245,000	791,000	487,000
Land
Recorded Investment
With no related allowance recorded	13,931,000	19,038,000	13,931,000	19,038,000	25,748,000
With an allowance recorded		8,098,000		8,098,000
Unpaid Contractual Principal Balance
With no related allowance recorded	27,092,000	23,606,000	27,092,000	23,606,000	41,016,000
With an allowance recorded		18,362,000		18,362,000
Related Allowance
Total impaired loans		1,467,000		1,467,000
Average Recorded Investment
With no related allowance recorded	14,056,000	18,987,000	16,506,000	22,763,000
With an allowance recorded		8,432,000	3,213,000	14,700,000
Interest Income Recognized
With no related allowance recorded	224,000	35,000	511,000	35,000
With an allowance recorded			213,000
Home equity loans and lines of credit
Recorded Investment
With no related allowance recorded	2,350,000	3,297,000	2,350,000	3,297,000	3,562,000
With an allowance recorded		1,199,000		1,199,000	899,000
Total impaired loans	2,350,000	4,496,000	2,350,000	4,496,000	4,461,000
Unpaid Contractual Principal Balance
With no related allowance recorded	3,375,000	4,370,000	3,375,000	4,370,000	4,660,000
With an allowance recorded		1,406,000		1,406,000	965,000
Total impaired loans	3,375,000	5,776,000	3,375,000	5,776,000	5,625,000
Related Allowance
Total impaired loans		138,000		138,000	116,000
Average Recorded Investment
With no related allowance recorded	2,803,000	3,252,000	2,827,000	4,470,000
With an allowance recorded		1,213,000	225,000	1,166,000
Total impaired loans	2,803,000	4,465,000	3,052,000	5,636,000
Interest Income Recognized
With no related allowance recorded	47,000		81,000
Total impaired loans	47,000		81,000
Installment loan
Recorded Investment
With no related allowance recorded		449,000		449,000	449,000
Total impaired loans		449,000		449,000	449,000
Unpaid Contractual Principal Balance
With no related allowance recorded		927,000		927,000	927,000
Total impaired loans		927,000		927,000	927,000
Average Recorded Investment
With no related allowance recorded		500,000	112,000	552,000
Total impaired loans		500,000	112,000	552,000
Consumer Installment loan
Recorded Investment
With no related allowance recorded		449,000		449,000	449,000
Unpaid Contractual Principal Balance
With no related allowance recorded		927,000		927,000	927,000
Average Recorded Investment
With no related allowance recorded		500,000	112,000	552,000
Lease financing
Average Recorded Investment
With no related allowance recorded				7,000
Total impaired loans				$ 7,000