Loans, Allowance for Loan and Lease Losses, and Reserve for Off-Balance Sheet Credit Commitments (Details 5) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Recorded Investment
With no related allowance recorded	$ 45,611	$ 79,470
With an allowance recorded	15,611	21,194
Total impaired loans	61,222	100,664
Unpaid Contractual Principal Balance
With no related allowance recorded	51,987	100,767
With an allowance recorded	18,352	25,607
Total impaired loans	70,339	126,374
Related Allowance
Total impaired loans	728	3,025
Average Recorded Investment
With no related allowance recorded	60,967	95,827
With an allowance recorded	21,197	22,613
Total impaired loans	82,164	118,440
Interest Income Recognized
With no related allowance recorded	1,683	3,825
With an allowance recorded	301	236
Total impaired loans	1,984	4,061
Commercial
Recorded Investment
With no related allowance recorded	8,894	17,721
With an allowance recorded	6,470	14,136
Total impaired loans	15,364	31,857
Unpaid Contractual Principal Balance
With no related allowance recorded	9,182	18,041
With an allowance recorded	8,878	18,156
Total impaired loans	18,060	36,197
Related Allowance
Total impaired loans	399	1,961
Average Recorded Investment
With no related allowance recorded	10,301	21,611
With an allowance recorded	13,989	8,871
Total impaired loans	24,290	30,482
Interest Income Recognized
With no related allowance recorded	241	1,664
With an allowance recorded		54
Total impaired loans	241	1,718
Commercial real estate mortgages
Recorded Investment
With no related allowance recorded	19,858	32,770
With an allowance recorded	5,184	5,384
Total impaired loans	25,042	38,154
Unpaid Contractual Principal Balance
With no related allowance recorded	22,416	37,555
With an allowance recorded	5,526	5,764
Total impaired loans	27,942	43,319
Related Allowance
Total impaired loans	281	586
Average Recorded Investment
With no related allowance recorded	27,554	33,002
With an allowance recorded	5,272	9,891
Total impaired loans	32,826	42,893
Interest Income Recognized
With no related allowance recorded	1,118	867
With an allowance recorded	263	182
Total impaired loans	1,381	1,049
Residential mortgages
Recorded Investment
With no related allowance recorded	7,980	7,537
With an allowance recorded	3,957	1,674
Total impaired loans	11,937	9,211
Unpaid Contractual Principal Balance
With no related allowance recorded	8,256	8,078
With an allowance recorded	3,948	1,687
Total impaired loans	12,204	9,765
Related Allowance
Total impaired loans	48	478
Average Recorded Investment
With no related allowance recorded	7,560	7,045
With an allowance recorded	1,926	1,101
Total impaired loans	9,486	8,146
Interest Income Recognized
With no related allowance recorded	108	178
With an allowance recorded	37
Total impaired loans	145	178
Fixed
Recorded Investment
With no related allowance recorded	7,756	2,135
Unpaid Contractual Principal Balance
With no related allowance recorded	7,994	2,295
Average Recorded Investment
With no related allowance recorded	4,318	2,715
With an allowance recorded		93
Interest Income Recognized
With no related allowance recorded	40	123
Variable
Recorded Investment
With no related allowance recorded	224	5,402
With an allowance recorded	3,957	1,674
Unpaid Contractual Principal Balance
With no related allowance recorded	262	5,783
With an allowance recorded	3,948	1,687
Related Allowance
Total impaired loans	48	478
Average Recorded Investment
With no related allowance recorded	3,242	4,330
With an allowance recorded	1,926	1,008
Interest Income Recognized
With no related allowance recorded	68	55
With an allowance recorded	37
Real estate construction
Recorded Investment
With no related allowance recorded	6,609	19,097
Total impaired loans	6,609	19,097
Unpaid Contractual Principal Balance
With no related allowance recorded	8,758	33,694
Total impaired loans	8,758	33,694
Average Recorded Investment
With no related allowance recorded	12,790	31,348
With an allowance recorded		2,570
Total impaired loans	12,790	33,918
Interest Income Recognized
With no related allowance recorded	215	1,116
Total impaired loans	215	1,116
Construction
Recorded Investment
With no related allowance recorded		5,485
Unpaid Contractual Principal Balance
With no related allowance recorded		6,766
Average Recorded Investment
With no related allowance recorded	2,194	15,421
Interest Income Recognized
With no related allowance recorded	76	927
Land.
Recorded Investment
With no related allowance recorded	6,609	13,612
Unpaid Contractual Principal Balance
With no related allowance recorded	8,758	26,928
Average Recorded Investment
With no related allowance recorded	10,596	15,927
With an allowance recorded	10	2,570
Interest Income Recognized
With no related allowance recorded	139	189
With an allowance recorded	1
Home equity loans and lines of credit
Recorded Investment
With no related allowance recorded	2,270	2,329
Total impaired loans	2,270	2,329
Unpaid Contractual Principal Balance
With no related allowance recorded	3,375	3,375
Total impaired loans	3,375	3,375
Average Recorded Investment
With no related allowance recorded	2,759	2,728
With an allowance recorded	10	180
Total impaired loans	2,759	2,908
Interest Income Recognized
With an allowance recorded	1
Installment
Recorded Investment
With no related allowance recorded		16
Total impaired loans		16
Unpaid Contractual Principal Balance
With no related allowance recorded		24
Total impaired loans		24
Average Recorded Investment
With no related allowance recorded	3	93
Total impaired loans	13	93
Interest Income Recognized
With no related allowance recorded	1
Total impaired loans	2
Consumer Installment loan
Recorded Investment
With no related allowance recorded		16
Unpaid Contractual Principal Balance
With no related allowance recorded		24
Average Recorded Investment
With no related allowance recorded	3	93
Interest Income Recognized
With no related allowance recorded	$ 1