Bank subsidiary (Details 11) (Class of financing receivables, USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
Mar. 31, 2013	Dec. 31, 2012
Recorded investment:
With no related allowance recorded	$ 29,282	$ 30,120
With an allowance recorded	37,846	34,641
Recorded investment	67,128	64,761
Unpaid principal balance:
With no related allowance recorded	41,403	42,189
With an allowance recorded	39,096	35,919
Unpaid principal balance	80,499	78,108
Related Allowance	7,851	6,799
Average recorded investment:
With no related allowance recorded	30,692	71,308
With an allowance recorded	35,215	21,382
Average recorded investment	65,907	92,690
Interest income recognized:
With no related allowance recorded	231	2,703
With an allowance recorded	219	848
Interest income recognized	450	3,551
Residential 1-4 family
Recorded investment:
With no related allowance recorded	14,815	14,633
With an allowance recorded	5,442	4,803
Recorded investment	20,257	19,436
Unpaid principal balance:
With no related allowance recorded	20,228	20,247
With an allowance recorded	5,442	4,803
Unpaid principal balance	25,670	25,050
Related Allowance	454	384
Average recorded investment:
With no related allowance recorded	14,756	16,688
With an allowance recorded	5,008	4,204
Average recorded investment	19,764	20,892
Interest income recognized:
With no related allowance recorded	134	294
With an allowance recorded	101	250
Interest income recognized	235	544
Commercial real estate
Recorded investment:
With no related allowance recorded		2,929
With an allowance recorded	10,662	3,821
Recorded investment	10,662	6,750
Unpaid principal balance:
With no related allowance recorded		2,929
With an allowance recorded	10,739	3,840
Unpaid principal balance	10,739	6,769
Related Allowance	3,169	535
Average recorded investment:
With no related allowance recorded	3,207	7,771
With an allowance recorded	6,100	1,295
Average recorded investment	9,307	9,066
Interest income recognized:
With no related allowance recorded		237
Interest income recognized		237
Home equity line of credit
Recorded investment:
With no related allowance recorded	732	581
Recorded investment	732	581
Unpaid principal balance:
With no related allowance recorded	1,444	1,374
Unpaid principal balance	1,444	1,374
Average recorded investment:
With no related allowance recorded	655	632
With an allowance recorded		26
Average recorded investment	655	658
Interest income recognized:
With no related allowance recorded		1
Interest income recognized		1
Residential land
Recorded investment:
With no related allowance recorded	9,141	7,691
With an allowance recorded	7,013	9,984
Recorded investment	16,154	17,675
Unpaid principal balance:
With no related allowance recorded	11,535	10,624
With an allowance recorded	7,140	10,364
Unpaid principal balance	18,675	20,988
Related Allowance	1,943	3,221
Average recorded investment:
With no related allowance recorded	7,833	21,589
With an allowance recorded	8,886	7,428
Average recorded investment	16,719	29,017
Interest income recognized:
With no related allowance recorded	97	1,185
With an allowance recorded	113	575
Interest income recognized	210	1,760
Commercial loans
Recorded investment:
With no related allowance recorded	4,573	4,265
With an allowance recorded	14,729	16,033
Recorded investment	19,302	20,298
Unpaid principal balance:
With no related allowance recorded	8,175	6,994
With an allowance recorded	15,775	16,912
Unpaid principal balance	23,950	23,906
Related Allowance	2,285	2,659
Average recorded investment:
With no related allowance recorded	4,220	24,605
With an allowance recorded	15,221	8,429
Average recorded investment	19,441	33,034
Interest income recognized:
With no related allowance recorded		986
With an allowance recorded	5	23
Interest income recognized	5	1,009
Consumer loans
Recorded investment:
With no related allowance recorded	21	21
Recorded investment	21	21
Unpaid principal balance:
With no related allowance recorded	21	21
Unpaid principal balance	21	21
Average recorded investment:
With no related allowance recorded	21	23
Average recorded investment	$ 21	$ 23

Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 15

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=7512638&loc=d3e5212-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 17

-URI http://asc.fasb.org/extlink&oid=7512638&loc=d3e5258-111524

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-SubTopic 10

-Section 50

-Paragraph 14A

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=7512638&loc=SL6953550-111524

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