Loans Receivable and Allowance for Loan Losses, Summary of Impaired loans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Residential Mortgage [Member]
Unpaid principal balance [Abstract]
With no related allowance	$ 9,819		$ 9,819		$ 12,929
With a related allowance	6,159		6,159		6,761
Total	15,978		15,978		19,690
Recorded investment [Abstract]
With no related allowance	8,995		8,995		11,572
With a related allowance	6,043		6,043		6,647
Total	15,038		15,038		18,219
Related allowance	1,090		1,090		1,181
Average recorded investment [Abstract]
With no related allowance	6,718	$ 10,423	9,618	$ 9,696
With a related allowance	6,020	8,910	6,899	9,231
Total	12,738	19,333	16,517	18,927
Interest income recognized [Abstract]
With no related allowance	75	138	229	353
With a related allowance	79	116	219	286
Total	154	254	448	639
Commercial [Member]
Average recorded investment [Abstract]
With no related allowance	6		59
With a related allowance				37
Total	6		59	37
Commercial Real Estate [Member]
Unpaid principal balance [Abstract]
With no related allowance	1,019		1,019		1,562
With a related allowance	1,102		1,102		1,410
Total	2,121		2,121		2,972
Recorded investment [Abstract]
With no related allowance	908		908		1,507
With a related allowance	1,145		1,145		1,410
Total	2,053		2,053		2,917
Related allowance	166		166		182
Average recorded investment [Abstract]
With no related allowance	1,572	1,531	1,240	2,652
With a related allowance	774	1,896	1,243	1,919
Total	2,346	3,427	2,483	4,571
Interest income recognized [Abstract]
With no related allowance	21	22	56	69
With a related allowance	4	23	19	73
Total	25	45	75	142
ADC [Member]
Unpaid principal balance [Abstract]
With no related allowance	522		522		636
With a related allowance	1,147		1,147		392
Total	1,669		1,669		1,028
Recorded investment [Abstract]
With no related allowance	522		522		636
With a related allowance	1,060		1,060		355
Total	1,582		1,582		991
Related allowance	900		900		48
Average recorded investment [Abstract]
With no related allowance	674	637	547	487
With a related allowance	176	369	1,103	385
Total	850	1,006	1,650	872
Interest income recognized [Abstract]
With no related allowance	7	9	20	21
With a related allowance	2	6	9	16
Total	9	15	29	37
Home Equity/2nds [Member]
Unpaid principal balance [Abstract]
With no related allowance	987		987
With a related allowance	14		14
Total	1,001		1,001
Recorded investment [Abstract]
With no related allowance	760		760
With a related allowance	12		12
Total	772		772
Related allowance	2		2
Average recorded investment [Abstract]
With no related allowance	371	918	552	679
With a related allowance	400	180	6	715
Total	771	1,098	558	1,394
Interest income recognized [Abstract]
With no related allowance	10	15	34	40
With a related allowance	4		11
Total	14	15	45	40
Consumer [Member]
Unpaid principal balance [Abstract]
With a related allowance	78		78		84
Total	78		78		84
Recorded investment [Abstract]
With a related allowance	78		78		84
Total	78		78		84
Related allowance	1		1		2
Average recorded investment [Abstract]
With a related allowance	79	88	81	91
Total	79	88	81	91
Interest income recognized [Abstract]
With a related allowance	1	1	2	2
Total	1	$ 1	2	$ 2
Residential Properties [Member]
Interest income recognized [Abstract]
Residential mortgage loans secured by residential real estate properties in formal foreclosure proceedings	$ 3,700		$ 3,700		$ 3,100