Loans, Impaired Loans, Average Investments in Impaired Loans, and Interest Income Recognized on Impaired Loans (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				12 Months Ended
	Mar. 31, 2014		Mar. 31, 2013		Dec. 31, 2013
Total impaired loans [Abstract]
Recorded balance	$ 65,286		$ 66,454		$ 65,300
Unpaid Contractual Principal Balance	68,227		72,539		68,228
Specific Allowance	2,135		3,425		2,296
Average investment in impaired loans	66,640		66,335		64,890
Interest Income Recognized	443	[1]	532	[1]	2,083	[1]
Commercial Construction [Member]
Loans without a specific valuation allowance [Abstract]
Recorded Balance	5,430		5,155		5,457
Unpaid Contractual Principal Balance	5,431		5,609		5,458
Specific Allowance	0		0		0
Average Investment in Impaired Loans	5,441		5,225		5,595
Interest Income Recognized	50	[1]	74	[1]	240	[1]
Loans with a specific valuation allowance [Abstract]
Recorded Balance	4,278		6,073		4,353
Unpaid Contractual Principal Balance	4,284		7,303		4,359
Specific Allowance	939		1,911		1,189
Average Investment in Impaired Loans	4,312		6,075		4,935
Interest income recognized	0	[1]	0	[1]	0	[1]
Total impaired loans [Abstract]
Recorded balance	9,708		11,228		9,810
Unpaid Contractual Principal Balance	9,715		12,912		9,817
Specific Allowance	939		1,911		1,189
Average investment in impaired loans	9,753		11,300		10,530
Interest Income Recognized	50	[1]	74	[1]	240	[1]
Commercial Secured by Real Estate [Member]
Loans without a specific valuation allowance [Abstract]
Recorded Balance	35,719		33,765		35,258
Unpaid Contractual Principal Balance	36,618		34,586		36,173
Specific Allowance	0		0		0
Average Investment in Impaired Loans	36,416		33,908		32,472
Interest Income Recognized	265	[1]	297	[1]	1,231	[1]
Loans with a specific valuation allowance [Abstract]
Recorded Balance	4,234		4,158		4,039
Unpaid Contractual Principal Balance	4,611		4,276		4,326
Specific Allowance	1,084		1,192		1,005
Average Investment in Impaired Loans	4,686		4,166		5,033
Interest income recognized	4	[1]	0	[1]	1	[1]
Total impaired loans [Abstract]
Recorded balance	39,953		37,923		39,297
Unpaid Contractual Principal Balance	41,229		38,862		40,499
Specific Allowance	1,084		1,192		1,005
Average investment in impaired loans	41,102		38,074		37,505
Interest Income Recognized	269	[1]	297	[1]	1,232	[1]
Commercial Other [Member]
Loans without a specific valuation allowance [Abstract]
Recorded Balance	14,191		15,779		14,839
Unpaid Contractual Principal Balance	15,726		17,920		16,435
Specific Allowance	0		0		0
Average Investment in Impaired Loans	14,324		15,435		15,396
Interest Income Recognized	114	[1]	154	[1]	568	[1]
Loans with a specific valuation allowance [Abstract]
Recorded Balance	413		867		330
Unpaid Contractual Principal Balance	536		2,188		453
Specific Allowance	112		322		102
Average Investment in Impaired Loans	439		868		525
Interest income recognized	0	[1]	0	[1]	0	[1]
Total impaired loans [Abstract]
Recorded balance	14,604		16,646		15,169
Unpaid Contractual Principal Balance	16,262		20,108		16,888
Specific Allowance	112		322		102
Average investment in impaired loans	14,763		16,303		15,921
Interest Income Recognized	114	[1]	154	[1]	568	[1]
Real Estate Mortgage [Member]
Loans without a specific valuation allowance [Abstract]
Recorded Balance	1,021		657		1,024
Unpaid Contractual Principal Balance	1,021		657		1,024
Specific Allowance	0		0		0
Average Investment in Impaired Loans	1,022		658		934
Interest Income Recognized	10	[1]	7	[1]	43	[1]
Total impaired loans [Abstract]
Recorded balance	1,021		657		1,024
Unpaid Contractual Principal Balance	1,021		657		1,024
Specific Allowance	0		0		0
Average investment in impaired loans	1,022		658		934
Interest Income Recognized	$ 10	[1]	$ 7	[1]	$ 43	[1]

[1] Cash basis interest is substantially the same as interest income recognized.