Bank subsidiary (Details 11) (Class of financing receivables, USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2013	Dec. 31, 2012
Recorded investment:
With no related allowance recorded	$ 22,708	$ 22,708	$ 30,120
With an allowance recorded	34,198	34,198	34,641
Recorded investment	56,906	56,906	64,761
Unpaid principal balance:
With no related allowance recorded	29,545	29,545	42,189
With an allowance recorded	35,909	35,909	35,919
Unpaid principal balance	65,454	65,454	78,108
Related Allowance	6,095	6,095	6,799
Average recorded investment:
With no related allowance recorded	21,359	25,994	71,308
With an allowance recorded	33,812	35,297	21,382
Average recorded investment	55,171	61,291	92,690
Interest income recognized:
With no related allowance recorded	285	737	2,703
With an allowance recorded	252	786	848
Interest income recognized	537	1,523	3,551
Residential 1-4 family
Recorded investment:
With no related allowance recorded	10,121	10,121	14,633
With an allowance recorded	7,147	7,147	4,803
Recorded investment	17,268	17,268	19,436
Unpaid principal balance:
With no related allowance recorded	13,122	13,122	20,247
With an allowance recorded	7,167	7,167	4,803
Unpaid principal balance	20,289	20,289	25,050
Related Allowance	943	943	384
Average recorded investment:
With no related allowance recorded	9,777	12,304	16,688
With an allowance recorded	7,155	6,411	4,204
Average recorded investment	16,932	18,715	20,892
Interest income recognized:
With no related allowance recorded	62	294	294
With an allowance recorded	83	259	250
Interest income recognized	145	553	544
Commercial real estate
Recorded investment:
With no related allowance recorded			2,929
With an allowance recorded	4,484	4,484	3,821
Recorded investment	4,484	4,484	6,750
Unpaid principal balance:
With no related allowance recorded			2,929
With an allowance recorded	4,536	4,536	3,840
Unpaid principal balance	4,536	4,536	6,769
Related Allowance	888	888	535
Average recorded investment:
With no related allowance recorded		1,069	7,771
With an allowance recorded	4,028	6,157	1,295
Average recorded investment	4,028	7,226	9,066
Interest income recognized:
With no related allowance recorded			237
With an allowance recorded	0	151
Interest income recognized	0	151	237
Home equity line of credit
Recorded investment:
With no related allowance recorded	523	523	581
Recorded investment	523	523	581
Unpaid principal balance:
With no related allowance recorded	1,068	1,068	1,374
Unpaid principal balance	1,068	1,068	1,374
Average recorded investment:
With no related allowance recorded	526	606	632
With an allowance recorded			26
Average recorded investment	526	606	658
Interest income recognized:
With no related allowance recorded			1
Interest income recognized			1
Residential land
Recorded investment:
With no related allowance recorded	5,734	5,734	7,691
With an allowance recorded	6,101	6,101	9,984
Recorded investment	11,835	11,835	17,675
Unpaid principal balance:
With no related allowance recorded	6,712	6,712	10,624
With an allowance recorded	6,228	6,228	10,364
Unpaid principal balance	12,940	12,940	20,988
Related Allowance	1,585	1,585	3,221
Average recorded investment:
With no related allowance recorded	6,095	7,477	21,589
With an allowance recorded	6,105	7,123	7,428
Average recorded investment	12,200	14,600	29,017
Interest income recognized:
With no related allowance recorded	216	435	1,185
With an allowance recorded	102	304	575
Interest income recognized	318	739	1,760
Commercial loans
Recorded investment:
With no related allowance recorded	6,311	6,311	4,265
With an allowance recorded	16,466	16,466	16,033
Recorded investment	22,777	22,777	20,298
Unpaid principal balance:
With no related allowance recorded	8,624	8,624	6,994
With an allowance recorded	17,978	17,978	16,912
Unpaid principal balance	26,602	26,602	23,906
Related Allowance	2,679	2,679	2,659
Average recorded investment:
With no related allowance recorded	4,941	4,518	24,605
With an allowance recorded	16,524	15,606	8,429
Average recorded investment	21,465	20,124	33,034
Interest income recognized:
With no related allowance recorded	7	8	986
With an allowance recorded	67	72	23
Interest income recognized	74	80	1,009
Consumer loans
Recorded investment:
With no related allowance recorded	19	19	21
Recorded investment	19	19	21
Unpaid principal balance:
With no related allowance recorded	19	19	21
Unpaid principal balance	19	19	21
Average recorded investment:
With no related allowance recorded	20	20	23
Average recorded investment	$ 20	$ 20	$ 23