Loans Receivable, Part IV (Details) - USD ($) | 3 Months Ended | 12 Months Ended | |
Mar. 31, 2017 | Dec. 31, 2015 | Dec. 31, 2016 |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | $ 1,194,848,000 | | $ 1,177,884,000 |
Loans requiring an officers' loans committee review and approval, minimum | 500,000 | | |
Minimum amount of potential loan exposure to be reviewed by credit management personnel | $ 1,000,000 | | |
Maximum period of time loan is reviewed if renewed | 1 year | | |
Period of time sales of real estate owned fair value is based | 2 years | | |
Impaired Loans Receivable, Recorded Investment [Abstract] | | | |
Total Impaired, with Reserve, Recorded Investment | $ 3,754,000 | | 3,476,000 |
Total Impaired, with no Reserve, Recorded Investment | 10,520,000 | | 12,586,000 |
Total Impaired, Recorded Investment | 14,274,000 | | 16,062,000 |
Impaired Loans Receivable, Unpaid Principal Balance [Abstract] | | | |
Total Impaired with Reserve, Unpaid Principal Balance | 4,163,000 | | 3,885,000 |
Total Impaired with no Reserve, Unpaid Principal Balance | 12,367,000 | | 14,929,000 |
Total Impaired, Unpaid Principal Balance, Total | 16,530,000 | | 18,814,000 |
Impaired Loans Receivable, Reserve [Abstract] | | | |
Total Impaired with Reserve, Reserve | 605,000 | | 662,000 |
Total Impaired with no Reserve, Reserve | 0 | | 0 |
Impaired Loans, Reserve | 605,000 | | 662,000 |
Impaired Loans Receivable, Cumulative Charge Offs [Abstract] | | | |
Total Impaired with Reserve, Cumulative Charge-offs | 409,000 | | 409,000 |
Total Impaired with no Reserve, Cumulative Charge-offs | 1,847,000 | | 2,343,000 |
Total Impaired, Cumulative Charge-offs | 2,256,000 | | 2,752,000 |
Impaired Loans Receivable, Average Recorded Investment [Abstract] | | | |
Total Impaired with Reserve, Average Recorded Investment | 3,781,000 | $ 3,558,000 | |
Total Impaired with no Reserve, Average Recorded Investment | 10,573,000 | 12,901,000 | |
Total Impaired, Average Recorded Investment, Total | 14,354,000 | 16,459,000 | |
Impaired Loans Receivable, Interest Paid YTD [Abstract] | | | |
Total Impaired with Reserve, Interest Paid YTD | 29,000 | 118,000 | |
Total Impaired with no Reserve, Interest Paid YTD | 120,000 | 655,000 | |
Total Impaired, Interest Paid YTD | 149,000 | 773,000 | |
Charge-offs recorded to reduce the unpaid principal balance | 1,800,000 | | |
Total impaired loans including troubled debt restructurings | 8,279,000 | | 10,137,000 |
Substandard [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | 12,269,000 | | 15,458,000 |
Watch [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | 16,890,000 | | 20,129,000 |
Pass [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | 1,165,689,000 | | 1,142,297,000 |
Residential Real Estate [Member] | One- to four-family [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | 396,187,000 | | 392,817,000 |
Impaired Loans Receivable, Recorded Investment [Abstract] | | | |
Total Impaired, with Reserve, Recorded Investment | 2,971,000 | | 3,007,000 |
Total Impaired, with no Reserve, Recorded Investment | 6,510,000 | | 7,913,000 |
Total Impaired, Recorded Investment | 9,481,000 | | 10,920,000 |
Impaired Loans Receivable, Unpaid Principal Balance [Abstract] | | | |
Total Impaired with Reserve, Unpaid Principal Balance | 2,971,000 | | 3,007,000 |
Total Impaired with no Reserve, Unpaid Principal Balance | 7,473,000 | | 9,245,000 |
Total Impaired, Unpaid Principal Balance, Total | 10,444,000 | | 12,252,000 |
Impaired Loans Receivable, Reserve [Abstract] | | | |
Total Impaired with Reserve, Reserve | 423,000 | | 499,000 |
Total Impaired with no Reserve, Reserve | 0 | | 0 |
Impaired Loans, Reserve | 423,000 | | 499,000 |
Impaired Loans Receivable, Cumulative Charge Offs [Abstract] | | | |
Total Impaired with Reserve, Cumulative Charge-offs | 0 | | 0 |
Total Impaired with no Reserve, Cumulative Charge-offs | 963,000 | | 1,332,000 |
Total Impaired, Cumulative Charge-offs | 963,000 | | 1,332,000 |
Impaired Loans Receivable, Average Recorded Investment [Abstract] | | | |
Total Impaired with Reserve, Average Recorded Investment | 2,985,000 | 3,063,000 | |
Total Impaired with no Reserve, Average Recorded Investment | 6,548,000 | 8,150,000 | |
Total Impaired, Average Recorded Investment, Total | 9,533,000 | 11,213,000 | |
Impaired Loans Receivable, Interest Paid YTD [Abstract] | | | |
Total Impaired with Reserve, Interest Paid YTD | 22,000 | 88,000 | |
Total Impaired with no Reserve, Interest Paid YTD | 70,000 | 401,000 | |
Total Impaired, Interest Paid YTD | 92,000 | 489,000 | |
Total impaired loans including troubled debt restructurings | 4,594,000 | | 5,695,000 |
Residential Real Estate [Member] | One- to four-family [Member] | Substandard [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | 9,103,000 | | 12,845,000 |
Residential Real Estate [Member] | One- to four-family [Member] | Watch [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | 11,930,000 | | 10,509,000 |
Residential Real Estate [Member] | One- to four-family [Member] | Pass [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | 375,154,000 | | 369,463,000 |
Residential Real Estate [Member] | Multi Family [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | 566,027,000 | | 558,592,000 |
Impaired Loans Receivable, Recorded Investment [Abstract] | | | |
Total Impaired, with Reserve, Recorded Investment | 374,000 | | 0 |
Total Impaired, with no Reserve, Recorded Investment | 3,347,000 | | 3,941,000 |
Total Impaired, Recorded Investment | 3,721,000 | | 3,941,000 |
Impaired Loans Receivable, Unpaid Principal Balance [Abstract] | | | |
Total Impaired with Reserve, Unpaid Principal Balance | 374,000 | | 0 |
Total Impaired with no Reserve, Unpaid Principal Balance | 4,231,000 | | 4,952,000 |
Total Impaired, Unpaid Principal Balance, Total | 4,605,000 | | 4,952,000 |
Impaired Loans Receivable, Reserve [Abstract] | | | |
Total Impaired with Reserve, Reserve | 46,000 | | 0 |
Total Impaired with no Reserve, Reserve | 0 | | 0 |
Impaired Loans, Reserve | 46,000 | | 0 |
Impaired Loans Receivable, Cumulative Charge Offs [Abstract] | | | |
Total Impaired with Reserve, Cumulative Charge-offs | 0 | | 0 |
Total Impaired with no Reserve, Cumulative Charge-offs | 884,000 | | 1,011,000 |
Total Impaired, Cumulative Charge-offs | 884,000 | | 1,011,000 |
Impaired Loans Receivable, Average Recorded Investment [Abstract] | | | |
Total Impaired with Reserve, Average Recorded Investment | 375,000 | 0 | |
Total Impaired with no Reserve, Average Recorded Investment | 3,359,000 | 4,005,000 | |
Total Impaired, Average Recorded Investment, Total | 3,734,000 | 4,005,000 | |
Impaired Loans Receivable, Interest Paid YTD [Abstract] | | | |
Total Impaired with Reserve, Interest Paid YTD | 0 | 0 | |
Total Impaired with no Reserve, Interest Paid YTD | 45,000 | 230,000 | |
Total Impaired, Interest Paid YTD | 45,000 | 230,000 | |
Total impaired loans including troubled debt restructurings | 3,346,000 | | 3,941,000 |
Residential Real Estate [Member] | Multi Family [Member] | Substandard [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | 1,217,000 | | 1,427,000 |
Residential Real Estate [Member] | Multi Family [Member] | Watch [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | 2,895,000 | | 3,975,000 |
Residential Real Estate [Member] | Multi Family [Member] | Pass [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | 561,915,000 | | 553,190,000 |
Residential Real Estate [Member] | Home Equity [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | 21,803,000 | | 21,778,000 |
Impaired Loans Receivable, Recorded Investment [Abstract] | | | |
Total Impaired, with Reserve, Recorded Investment | 150,000 | | 188,000 |
Total Impaired, with no Reserve, Recorded Investment | 149,000 | | 254,000 |
Total Impaired, Recorded Investment | 299,000 | | 442,000 |
Impaired Loans Receivable, Unpaid Principal Balance [Abstract] | | | |
Total Impaired with Reserve, Unpaid Principal Balance | 150,000 | | 188,000 |
Total Impaired with no Reserve, Unpaid Principal Balance | 149,000 | | 254,000 |
Total Impaired, Unpaid Principal Balance, Total | 299,000 | | 442,000 |
Impaired Loans Receivable, Reserve [Abstract] | | | |
Total Impaired with Reserve, Reserve | 73,000 | | 79,000 |
Total Impaired with no Reserve, Reserve | 0 | | 0 |
Impaired Loans, Reserve | 73,000 | | 79,000 |
Impaired Loans Receivable, Cumulative Charge Offs [Abstract] | | | |
Total Impaired with Reserve, Cumulative Charge-offs | 0 | | 0 |
Total Impaired with no Reserve, Cumulative Charge-offs | 0 | | 0 |
Total Impaired, Cumulative Charge-offs | 0 | | 0 |
Impaired Loans Receivable, Average Recorded Investment [Abstract] | | | |
Total Impaired with Reserve, Average Recorded Investment | 151,000 | 198,000 | |
Total Impaired with no Reserve, Average Recorded Investment | 150,000 | 258,000 | |
Total Impaired, Average Recorded Investment, Total | 301,000 | 456,000 | |
Impaired Loans Receivable, Interest Paid YTD [Abstract] | | | |
Total Impaired with Reserve, Interest Paid YTD | 3,000 | 15,000 | |
Total Impaired with no Reserve, Interest Paid YTD | 1,000 | 9,000 | |
Total Impaired, Interest Paid YTD | 4,000 | 24,000 | |
Total impaired loans including troubled debt restructurings | | | 146,000 |
Residential Real Estate [Member] | Home Equity [Member] | Substandard [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | 285,000 | | 428,000 |
Residential Real Estate [Member] | Home Equity [Member] | Watch [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | 54,000 | | 149,000 |
Residential Real Estate [Member] | Home Equity [Member] | Pass [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | 21,464,000 | | 21,201,000 |
Construction and Land [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | 20,900,000 | | 18,179,000 |
Impaired Loans Receivable, Recorded Investment [Abstract] | | | |
Total Impaired, with Reserve, Recorded Investment | 0 | | 0 |
Total Impaired, with no Reserve, Recorded Investment | 51,000 | | 0 |
Total Impaired, Recorded Investment | 51,000 | | 0 |
Impaired Loans Receivable, Unpaid Principal Balance [Abstract] | | | |
Total Impaired with Reserve, Unpaid Principal Balance | 0 | | 0 |
Total Impaired with no Reserve, Unpaid Principal Balance | 51,000 | | 0 |
Total Impaired, Unpaid Principal Balance, Total | 51,000 | | 0 |
Impaired Loans Receivable, Reserve [Abstract] | | | |
Total Impaired with Reserve, Reserve | 0 | | 0 |
Total Impaired with no Reserve, Reserve | 0 | | 0 |
Impaired Loans, Reserve | 0 | | 0 |
Impaired Loans Receivable, Cumulative Charge Offs [Abstract] | | | |
Total Impaired with Reserve, Cumulative Charge-offs | 0 | | 0 |
Total Impaired with no Reserve, Cumulative Charge-offs | 0 | | 0 |
Total Impaired, Cumulative Charge-offs | 0 | | 0 |
Impaired Loans Receivable, Average Recorded Investment [Abstract] | | | |
Total Impaired with Reserve, Average Recorded Investment | 0 | 0 | |
Total Impaired with no Reserve, Average Recorded Investment | 51,000 | 0 | |
Total Impaired, Average Recorded Investment, Total | 51,000 | 0 | |
Impaired Loans Receivable, Interest Paid YTD [Abstract] | | | |
Total Impaired with Reserve, Interest Paid YTD | 0 | 0 | |
Total Impaired with no Reserve, Interest Paid YTD | 0 | 0 | |
Total Impaired, Interest Paid YTD | 0 | 0 | |
Total impaired loans including troubled debt restructurings | 45,000 | | |
Construction and Land [Member] | Substandard [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | 51,000 | | 0 |
Construction and Land [Member] | Watch [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | 0 | | 436,000 |
Construction and Land [Member] | Pass [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | 20,849,000 | | 17,743,000 |
Commercial Real Estate [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | 162,870,000 | | 159,401,000 |
Impaired Loans Receivable, Recorded Investment [Abstract] | | | |
Total Impaired, with Reserve, Recorded Investment | 259,000 | | 280,000 |
Total Impaired, with no Reserve, Recorded Investment | 437,000 | | 438,000 |
Total Impaired, Recorded Investment | 696,000 | | 718,000 |
Impaired Loans Receivable, Unpaid Principal Balance [Abstract] | | | |
Total Impaired with Reserve, Unpaid Principal Balance | 668,000 | | 689,000 |
Total Impaired with no Reserve, Unpaid Principal Balance | 437,000 | | 438,000 |
Total Impaired, Unpaid Principal Balance, Total | 1,105,000 | | 1,127,000 |
Impaired Loans Receivable, Reserve [Abstract] | | | |
Total Impaired with Reserve, Reserve | 63,000 | | 83,000 |
Total Impaired with no Reserve, Reserve | 0 | | 0 |
Impaired Loans, Reserve | 63,000 | | 83,000 |
Impaired Loans Receivable, Cumulative Charge Offs [Abstract] | | | |
Total Impaired with Reserve, Cumulative Charge-offs | 409,000 | | 409,000 |
Total Impaired with no Reserve, Cumulative Charge-offs | 0 | | 0 |
Total Impaired, Cumulative Charge-offs | 409,000 | | 409,000 |
Impaired Loans Receivable, Average Recorded Investment [Abstract] | | | |
Total Impaired with Reserve, Average Recorded Investment | 270,000 | 295,000 | |
Total Impaired with no Reserve, Average Recorded Investment | 438,000 | 442,000 | |
Total Impaired, Average Recorded Investment, Total | 708,000 | 737,000 | |
Impaired Loans Receivable, Interest Paid YTD [Abstract] | | | |
Total Impaired with Reserve, Interest Paid YTD | 4,000 | 15,000 | |
Total Impaired with no Reserve, Interest Paid YTD | 4,000 | 13,000 | |
Total Impaired, Interest Paid YTD | 8,000 | 28,000 | |
Total impaired loans including troubled debt restructurings | 294,000 | | 355,000 |
Commercial Real Estate [Member] | Substandard [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | 696,000 | | 717,000 |
Commercial Real Estate [Member] | Watch [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | 343,000 | | 1,389,000 |
Commercial Real Estate [Member] | Pass [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | 161,831,000 | | 157,295,000 |
Consumer [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | 257,000 | | 319,000 |
Impaired Loans Receivable, Recorded Investment [Abstract] | | | |
Total Impaired, with Reserve, Recorded Investment | 0 | | 0 |
Total Impaired, with no Reserve, Recorded Investment | 0 | | 0 |
Total Impaired, Recorded Investment | 0 | | 0 |
Impaired Loans Receivable, Unpaid Principal Balance [Abstract] | | | |
Total Impaired with Reserve, Unpaid Principal Balance | 0 | | 0 |
Total Impaired with no Reserve, Unpaid Principal Balance | 0 | | 0 |
Total Impaired, Unpaid Principal Balance, Total | 0 | | 0 |
Impaired Loans Receivable, Reserve [Abstract] | | | |
Total Impaired with Reserve, Reserve | 0 | | 0 |
Total Impaired with no Reserve, Reserve | 0 | | 0 |
Impaired Loans, Reserve | 0 | | 0 |
Impaired Loans Receivable, Cumulative Charge Offs [Abstract] | | | |
Total Impaired with Reserve, Cumulative Charge-offs | 0 | | 0 |
Total Impaired with no Reserve, Cumulative Charge-offs | 0 | | 0 |
Total Impaired, Cumulative Charge-offs | 0 | | 0 |
Impaired Loans Receivable, Average Recorded Investment [Abstract] | | | |
Total Impaired with Reserve, Average Recorded Investment | 0 | 0 | |
Total Impaired with no Reserve, Average Recorded Investment | 0 | 0 | |
Total Impaired, Average Recorded Investment, Total | 0 | 0 | |
Impaired Loans Receivable, Interest Paid YTD [Abstract] | | | |
Total Impaired with Reserve, Interest Paid YTD | 0 | 0 | |
Total Impaired with no Reserve, Interest Paid YTD | 0 | 0 | |
Total Impaired, Interest Paid YTD | 0 | 0 | |
Consumer [Member] | Substandard [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | 0 | | 0 |
Consumer [Member] | Watch [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | 0 | | 0 |
Consumer [Member] | Pass [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | 257,000 | | 319,000 |
Commercial Loans [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | 26,804,000 | | 26,798,000 |
Impaired Loans Receivable, Recorded Investment [Abstract] | | | |
Total Impaired, with Reserve, Recorded Investment | 0 | | 1,000 |
Total Impaired, with no Reserve, Recorded Investment | 26,000 | | 40,000 |
Total Impaired, Recorded Investment | 26,000 | | 41,000 |
Impaired Loans Receivable, Unpaid Principal Balance [Abstract] | | | |
Total Impaired with Reserve, Unpaid Principal Balance | 0 | | 1,000 |
Total Impaired with no Reserve, Unpaid Principal Balance | 26,000 | | 40,000 |
Total Impaired, Unpaid Principal Balance, Total | 26,000 | | 41,000 |
Impaired Loans Receivable, Reserve [Abstract] | | | |
Total Impaired with Reserve, Reserve | 0 | | 1,000 |
Total Impaired with no Reserve, Reserve | 0 | | 0 |
Impaired Loans, Reserve | 0 | | 1,000 |
Impaired Loans Receivable, Cumulative Charge Offs [Abstract] | | | |
Total Impaired with Reserve, Cumulative Charge-offs | 0 | | 0 |
Total Impaired with no Reserve, Cumulative Charge-offs | 0 | | 0 |
Total Impaired, Cumulative Charge-offs | 0 | | 0 |
Impaired Loans Receivable, Average Recorded Investment [Abstract] | | | |
Total Impaired with Reserve, Average Recorded Investment | 0 | 2,000 | |
Total Impaired with no Reserve, Average Recorded Investment | 27,000 | 46,000 | |
Total Impaired, Average Recorded Investment, Total | 27,000 | 48,000 | |
Impaired Loans Receivable, Interest Paid YTD [Abstract] | | | |
Total Impaired with Reserve, Interest Paid YTD | 0 | 0 | |
Total Impaired with no Reserve, Interest Paid YTD | 0 | 2,000 | |
Total Impaired, Interest Paid YTD | 0 | $ 2,000 | |
Commercial Loans [Member] | Substandard [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | 917,000 | | 41,000 |
Commercial Loans [Member] | Watch [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | 1,668,000 | | 3,671,000 |
Commercial Loans [Member] | Pass [Member] | | | |
Loans Receivable, Recorded Investment [Line Items] | | | |
At December 31, 2016 | $ 24,219,000 | | $ 23,086,000 |