Loans and Allowance for Loan Losses - Impaired loans by loan portfolio class (Details 4) (Loans Receivable, USD $) | 3 Months Ended | 9 Months Ended | |
In Thousands, unless otherwise specified | Sep. 30, 2013 | Sep. 30, 2012 | Sep. 30, 2013 | Sep. 30, 2012 | Dec. 31, 2012 |
Financing Receivable, Impaired [Line Items] | ' | ' | ' | ' | ' |
Impaired Financing Receivable, with Related Allowance, Recorded Investment | $6,136 | ' | $6,136 | ' | $479 |
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance | 6,877 | ' | 6,877 | ' | 486 |
Impaired Financing Receivable, Related Allowance | 755 | ' | 755 | ' | 101 |
Impaired Financing Receivable, with No Related Allowance, Recorded Investment | 19,527 | ' | 19,527 | ' | 30,226 |
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance | 23,895 | ' | 23,895 | ' | 36,422 |
Impaired Financing Receivable, Recorded Investment | 25,663 | ' | 25,663 | ' | 30,705 |
Impaired Financing Receivable, Unpaid Principal Balance | 30,772 | ' | 30,772 | ' | 36,908 |
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment | 6,835 | ' | 6,879 | ' | ' |
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method | 73 | ' | 105 | ' | ' |
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment | 20,064 | 27,787 | 20,351 | 29,213 | ' |
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method | 226 | 262 | 548 | 794 | ' |
Impaired Financing Receivable, Average Recorded Investment | 26,899 | 27,787 | 27,230 | 29,213 | ' |
Impaired Financing Receivable, Interest Income, Accrual Method | 299 | 262 | 653 | 794 | ' |
Real estate loans: One- to four-family | ' | ' | ' | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' | ' | ' | ' |
Impaired Financing Receivable, with Related Allowance, Recorded Investment | 2,294 | ' | 2,294 | ' | ' |
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance | 2,438 | ' | 2,438 | ' | ' |
Impaired Financing Receivable, Related Allowance | 119 | ' | 119 | ' | ' |
Impaired Financing Receivable, with No Related Allowance, Recorded Investment | 6,109 | ' | 6,109 | ' | 7,456 |
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance | 7,232 | ' | 7,232 | ' | 8,601 |
Impaired Financing Receivable, Recorded Investment | 8,403 | ' | 8,403 | ' | 7,456 |
Impaired Financing Receivable, Unpaid Principal Balance | 9,670 | ' | 9,670 | ' | 8,601 |
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment | 2,375 | ' | 2,393 | ' | ' |
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method | 27 | ' | 57 | ' | ' |
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment | 6,155 | 7,394 | 6,225 | 7,789 | ' |
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method | 63 | 59 | 157 | 139 | ' |
Impaired Financing Receivable, Average Recorded Investment | 8,530 | 7,394 | 8,618 | 7,789 | ' |
Impaired Financing Receivable, Interest Income, Accrual Method | 90 | 59 | 214 | 139 | ' |
Real estate loans: Multi-family | ' | ' | ' | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' | ' | ' | ' |
Impaired Financing Receivable, with Related Allowance, Recorded Investment | ' | ' | ' | ' | ' |
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance | ' | ' | ' | ' | ' |
Impaired Financing Receivable, Related Allowance | ' | ' | ' | ' | ' |
Impaired Financing Receivable, with No Related Allowance, Recorded Investment | ' | ' | ' | ' | ' |
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance | ' | ' | ' | ' | ' |
Impaired Financing Receivable, Recorded Investment | ' | ' | ' | ' | ' |
Impaired Financing Receivable, Unpaid Principal Balance | ' | ' | ' | ' | ' |
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment | ' | ' | ' | ' | ' |
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method | ' | ' | ' | ' | ' |
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment | ' | ' | ' | ' | ' |
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method | ' | ' | ' | ' | ' |
Impaired Financing Receivable, Average Recorded Investment | ' | ' | ' | ' | ' |
Impaired Financing Receivable, Interest Income, Accrual Method | ' | ' | ' | ' | ' |
Real estate loans: Commercial | ' | ' | ' | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' | ' | ' | ' |
Impaired Financing Receivable, with Related Allowance, Recorded Investment | 2,228 | ' | 2,228 | ' | ' |
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance | 2,230 | ' | 2,230 | ' | ' |
Impaired Financing Receivable, Related Allowance | 3 | ' | 3 | ' | ' |
Impaired Financing Receivable, with No Related Allowance, Recorded Investment | 8,047 | ' | 8,047 | ' | 15,128 |
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance | 11,336 | ' | 11,336 | ' | 19,667 |
Impaired Financing Receivable, Recorded Investment | 10,275 | ' | 10,275 | ' | 15,128 |
Impaired Financing Receivable, Unpaid Principal Balance | 13,566 | ' | 13,566 | ' | 19,667 |
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment | 2,238 | ' | 2,253 | ' | ' |
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method | 28 | ' | 30 | ' | ' |
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment | 8,998 | 4,604 | 9,108 | 15,493 | ' |
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method | 139 | 35 | 303 | 537 | ' |
Impaired Financing Receivable, Average Recorded Investment | 11,236 | 4,604 | 11,361 | 15,493 | ' |
Impaired Financing Receivable, Interest Income, Accrual Method | 161 | 35 | 333 | 537 | ' |
Real estate loans: Construction and land | ' | ' | ' | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' | ' | ' | ' |
Impaired Financing Receivable, with Related Allowance, Recorded Investment | 1,479 | ' | 1,479 | ' | ' |
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance | 1,612 | ' | 1,612 | ' | ' |
Impaired Financing Receivable, Related Allowance | 133 | ' | 133 | ' | ' |
Impaired Financing Receivable, with No Related Allowance, Recorded Investment | 1,922 | ' | 1,922 | ' | 4,177 |
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance | 1,789 | ' | 1,789 | ' | 4,204 |
Impaired Financing Receivable, Recorded Investment | 3,401 | ' | 3,401 | ' | 4,177 |
Impaired Financing Receivable, Unpaid Principal Balance | 3,401 | ' | 3,401 | ' | 4,204 |
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment | 1,612 | ' | 1,612 | ' | ' |
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method | 12 | ' | 12 | ' | ' |
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment | 1,826 | 487 | 1,901 | 4,624 | ' |
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method | ' | 5 | 25 | 103 | ' |
Impaired Financing Receivable, Average Recorded Investment | 3,438 | 487 | 3,513 | 4,624 | ' |
Impaired Financing Receivable, Interest Income, Accrual Method | 12 | 5 | 37 | 103 | ' |
Real estate loans: Home equity loans and lines of credit | ' | ' | ' | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' | ' | ' | ' |
Impaired Financing Receivable, with Related Allowance, Recorded Investment | 135 | ' | 135 | ' | 93 |
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance | 143 | ' | 143 | ' | 93 |
Impaired Financing Receivable, Related Allowance | 8 | ' | 8 | ' | 93 |
Impaired Financing Receivable, with No Related Allowance, Recorded Investment | 587 | ' | 587 | ' | 723 |
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance | 766 | ' | 766 | ' | 907 |
Impaired Financing Receivable, Recorded Investment | 722 | ' | 722 | ' | 816 |
Impaired Financing Receivable, Unpaid Principal Balance | 909 | ' | 909 | ' | 1,000 |
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment | 146 | ' | 147 | ' | ' |
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method | 3 | ' | 3 | ' | ' |
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment | 597 | 13,534 | 603 | 564 | ' |
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method | 10 | 162 | 21 | 13 | ' |
Impaired Financing Receivable, Average Recorded Investment | 743 | 13,534 | 750 | 564 | ' |
Impaired Financing Receivable, Interest Income, Accrual Method | 13 | 162 | 24 | 13 | ' |
Commercial | ' | ' | ' | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' | ' | ' | ' |
Impaired Financing Receivable, with Related Allowance, Recorded Investment | ' | ' | ' | ' | 384 |
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance | 454 | ' | 454 | ' | 387 |
Impaired Financing Receivable, Related Allowance | 492 | ' | 492 | ' | 7 |
Impaired Financing Receivable, with No Related Allowance, Recorded Investment | 2,861 | ' | 2,861 | ' | 2,742 |
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance | 2,768 | ' | 2,768 | ' | 3,043 |
Impaired Financing Receivable, Recorded Investment | 2,861 | ' | 2,861 | ' | 3,126 |
Impaired Financing Receivable, Unpaid Principal Balance | 3,222 | ' | 3,222 | ' | 3,430 |
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment | 464 | ' | 474 | ' | ' |
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method | 3 | ' | 3 | ' | ' |
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment | 2,486 | 1,759 | 2,512 | 731 | ' |
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method | 14 | ' | 42 | 1 | ' |
Impaired Financing Receivable, Average Recorded Investment | 2,950 | 1,759 | 2,986 | 731 | ' |
Impaired Financing Receivable, Interest Income, Accrual Method | 17 | ' | 45 | 1 | ' |
Consumer | ' | ' | ' | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' | ' | ' | ' |
Impaired Financing Receivable, with Related Allowance, Recorded Investment | ' | ' | ' | ' | 2 |
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance | ' | ' | ' | ' | 6 |
Impaired Financing Receivable, Related Allowance | ' | ' | ' | ' | 1 |
Impaired Financing Receivable, with No Related Allowance, Recorded Investment | 1 | ' | 1 | ' | ' |
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance | 4 | ' | 4 | ' | ' |
Impaired Financing Receivable, Recorded Investment | 1 | ' | 1 | ' | 2 |
Impaired Financing Receivable, Unpaid Principal Balance | 4 | ' | 4 | ' | 6 |
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment | ' | ' | ' | ' | ' |
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method | ' | ' | ' | ' | ' |
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment | 2 | 9 | 2 | 12 | ' |
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method | ' | 1 | ' | 1 | ' |
Impaired Financing Receivable, Average Recorded Investment | 2 | 9 | 2 | 12 | ' |
Impaired Financing Receivable, Interest Income, Accrual Method | ' | $1 | ' | $1 | ' |