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Loans (Analysis of Impaired Loans) (Details) - Loans, Excluding Purchased Credit Impaired Loans [Member] - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items] |  |  |  |  |
Recorded Investment of Loans Collectively Measured for Contingency Provision | $ 6,345,954 |  | $ 6,345,954 |  | $ 6,042,304
Recorded Investment of Loans Individually Measured for Specific Impairment | 45,575 |  | 45,575 |  | 25,459
Recorded Investment | 38,905 |  | 38,905 |  | 17,592
Unpaid Principal Balance | 48,079 |  | 48,079 |  | 27,228
Related Allowance | 102 |  | 102 |  | 761
Average Recorded Investment Impaired Loans | 42,623 | $ 18,556 | 33,508 | $ 20,502 |
Interest Recognized on Impaired Loans | 374 | 54 | 664 | 125 |
Secured Loans [Member] |  |  |  |  |
Financing Receivable, Recorded Investment [Line Items] |  |  |  |  |
Recorded Investment of Loans Collectively Measured for Contingency Provision | 2,614,647 |  | 2,614,647 |  | 2,442,772
Recorded Investment of Loans Individually Measured for Specific Impairment | 21,399 |  | 21,399 |  | 8,818
Recorded Investment | 0 |  | 0 |  | 2,414
Unpaid Principal Balance | 0 |  | 0 |  | 2,484
Related Allowance | 0 |  | 0 |  | 664
Average Recorded Investment Impaired Loans | 22,395 | 6,909 | 15,349 | 9,506 |
Interest Recognized on Impaired Loans | 2 | 15 | 25 | 48 |
Unsecured Loans [Member] |  |  |  |  |
Financing Receivable, Recorded Investment [Line Items] |  |  |  |  |
Recorded Investment of Loans Collectively Measured for Contingency Provision | 93,924 |  | 93,924 |  | 94,737
Recorded Investment of Loans Individually Measured for Specific Impairment | 0 |  | 0 |  | 0
Recorded Investment | 0 |  | 0 |  | 0
Unpaid Principal Balance | 0 |  | 0 |  | 0
Related Allowance | 0 |  | 0 |  | 0
Average Recorded Investment Impaired Loans | 0 | 0 | 0 | 0 |
Interest Recognized on Impaired Loans | 0 | 0 | 0 | 0 |
One-to-Four Family Residential [Member] |  |  |  |  |
Financing Receivable, Recorded Investment [Line Items] |  |  |  |  |
Recorded Investment of Loans Collectively Measured for Contingency Provision | 173,562 |  | 173,562 |  | 167,403
Recorded Investment of Loans Individually Measured for Specific Impairment | 928 |  | 928 |  | 529
Recorded Investment | 459 |  | 459 |  | 435
Unpaid Principal Balance | 736 |  | 736 |  | 693
Related Allowance | 26 |  | 26 |  | 12
Average Recorded Investment Impaired Loans | 856 | 617 | 688 | 796 |
Interest Recognized on Impaired Loans | 15 | 5 | 37 | 8 |
Commercial Land [Member] |  |  |  |  |
Financing Receivable, Recorded Investment [Line Items] |  |  |  |  |
Recorded Investment of Loans Collectively Measured for Contingency Provision | 283,355 |  | 283,355 |  | 270,106
Recorded Investment of Loans Individually Measured for Specific Impairment | 2,299 |  | 2,299 |  | 708
Recorded Investment | 0 |  | 0 |  | 0
Unpaid Principal Balance | 0 |  | 0 |  | 0
Related Allowance | 0 |  | 0 |  | 0
Average Recorded Investment Impaired Loans | 2,549 | 708 | 2,026 | 354 |
Interest Recognized on Impaired Loans | 0 | 0 | 0 | 0 |
Income Property Multifamily [Member] |  |  |  |  |
Financing Receivable, Recorded Investment [Line Items] |  |  |  |  |
Recorded Investment of Loans Collectively Measured for Contingency Provision | 1,378,127 |  | 1,378,127 |  | 1,365,321
Recorded Investment of Loans Individually Measured for Specific Impairment | 4,771 |  | 4,771 |  | 4,425
Recorded Investment | 519 |  | 519 |  | 540
Unpaid Principal Balance | 523 |  | 523 |  | 544
Related Allowance | 25 |  | 25 |  | 27
Average Recorded Investment Impaired Loans | 4,214 | 1,939 | 4,137 | 2,010 |
Interest Recognized on Impaired Loans | 21 | 8 | 27 | 19 |
Owner Occupied [Member] |  |  |  |  |
Financing Receivable, Recorded Investment [Line Items] |  |  |  |  |
Recorded Investment of Loans Collectively Measured for Contingency Provision | 1,134,945 |  | 1,134,945 |  | 1,054,564
Recorded Investment of Loans Individually Measured for Specific Impairment | 5,663 |  | 5,663 |  | 5,414
Recorded Investment | 0 |  | 0 |  | 0
Unpaid Principal Balance | 0 |  | 0 |  | 0
Related Allowance | 0 |  | 0 |  | 0
Average Recorded Investment Impaired Loans | 4,530 | 4,486 | 4,496 | 5,001 |
Interest Recognized on Impaired Loans | 127 | 0 | 319 | 0 |
Land And Acquisition [Member] |  |  |  |  |
Financing Receivable, Recorded Investment [Line Items] |  |  |  |  |
Recorded Investment of Loans Collectively Measured for Contingency Provision | 6,813 |  | 6,813 |  | 11,542
Recorded Investment of Loans Individually Measured for Specific Impairment | 0 |  | 0 |  | 14
Recorded Investment | 0 |  | 0 |  | 14
Unpaid Principal Balance | 0 |  | 0 |  | 102
Related Allowance | 0 |  | 0 |  | 1
Average Recorded Investment Impaired Loans | 0 | 103 | 4 | 245 |
Interest Recognized on Impaired Loans | 0 | 1 | 0 | 4 |
Residential Construction [Member] |  |  |  |  |
Financing Receivable, Recorded Investment [Line Items] |  |  |  |  |
Recorded Investment of Loans Collectively Measured for Contingency Provision | 137,920 |  | 137,920 |  | 109,293
Recorded Investment of Loans Individually Measured for Specific Impairment | 0 |  | 0 |  | 336
Recorded Investment | 0 |  | 0 |  | 0
Unpaid Principal Balance | 0 |  | 0 |  | 0
Related Allowance | 0 |  | 0 |  | 0
Average Recorded Investment Impaired Loans | 0 | 449 | 84 | 506 |
Interest Recognized on Impaired Loans | 0 | 0 | 0 | 0 |
Income Property Multifamily Construction [Member] |  |  |  |  |
Financing Receivable, Recorded Investment [Line Items] |  |  |  |  |
Recorded Investment of Loans Collectively Measured for Contingency Provision | 172,112 |  | 172,112 |  | 103,779
Recorded Investment of Loans Individually Measured for Specific Impairment | 0 |  | 0 |  | 0
Recorded Investment | 0 |  | 0 |  | 0
Unpaid Principal Balance | 0 |  | 0 |  | 0
Related Allowance | 0 |  | 0 |  | 0
Owner Occupied Construction [Member] |  |  |  |  |
Financing Receivable, Recorded Investment [Line Items] |  |  |  |  |
Recorded Investment of Loans Collectively Measured for Contingency Provision | 35,511 |  | 35,511 |  | 103,480
Recorded Investment of Loans Individually Measured for Specific Impairment | 4,050 |  | 4,050 |  | 0
Recorded Investment | 0 |  | 0 |  | 0
Unpaid Principal Balance | 0 |  | 0 |  | 0
Related Allowance | 0 |  | 0 |  | 0
Average Recorded Investment Impaired Loans | 2,025 | 0 | 1,012 | 0 |
Interest Recognized on Impaired Loans | 151 | 0 | 151 | 0 |
Consumer Portfolio Segment [Member] |  |  |  |  |
Financing Receivable, Recorded Investment [Line Items] |  |  |  |  |
Recorded Investment of Loans Collectively Measured for Contingency Provision | 315,038 |  | 315,038 |  | 319,307
Recorded Investment of Loans Individually Measured for Specific Impairment | 6,465 |  | 6,465 |  | 5,215
Recorded Investment | 5,692 |  | 5,692 |  | 4,464
Unpaid Principal Balance | 5,982 |  | 5,982 |  | 4,558
Related Allowance | 51 |  | 51 |  | 57
Average Recorded Investment Impaired Loans | 6,054 | 3,345 | 5,712 | 2,084 |
Interest Recognized on Impaired Loans | 58 | $ 25 | 105 | $ 46 |
Impaired Loans With Recorded Allowance [Member] |  |  |  |  |
Financing Receivable, Recorded Investment [Line Items] |  |  |  |  |
Recorded Investment | 6,670 |  | 6,670 |  | 7,867
Unpaid Principal Balance | 7,241 |  | 7,241 |  | 8,381
Impaired Loans Without Recorded Allowance [Member] | Secured Loans [Member] |  |  |  |  |
Financing Receivable, Recorded Investment [Line Items] |  |  |  |  |
Recorded Investment | 21,399 |  | 21,399 |  | 6,404
Unpaid Principal Balance | 26,655 |  | 26,655 |  | 12,831
Impaired Loans Without Recorded Allowance [Member] | Unsecured Loans [Member] |  |  |  |  |
Financing Receivable, Recorded Investment [Line Items] |  |  |  |  |
Recorded Investment | 0 |  | 0 |  | 0
Unpaid Principal Balance | 0 |  | 0 |  | 0
Impaired Loans Without Recorded Allowance [Member] | One-to-Four Family Residential [Member] |  |  |  |  |
Financing Receivable, Recorded Investment [Line Items] |  |  |  |  |
Recorded Investment | 469 |  | 469 |  | 94
Unpaid Principal Balance | 1,030 |  | 1,030 |  | 291
Impaired Loans Without Recorded Allowance [Member] | Commercial Land [Member] |  |  |  |  |
Financing Receivable, Recorded Investment [Line Items] |  |  |  |  |
Recorded Investment | 2,299 |  | 2,299 |  | 708
Unpaid Principal Balance | 2,287 |  | 2,287 |  | 687
Impaired Loans Without Recorded Allowance [Member] | Income Property Multifamily [Member] |  |  |  |  |
Financing Receivable, Recorded Investment [Line Items] |  |  |  |  |
Recorded Investment | 4,252 |  | 4,252 |  | 3,885
Unpaid Principal Balance | 4,570 |  | 4,570 |  | 4,148
Impaired Loans Without Recorded Allowance [Member] | Owner Occupied [Member] |  |  |  |  |
Financing Receivable, Recorded Investment [Line Items] |  |  |  |  |
Recorded Investment | 5,663 |  | 5,663 |  | 5,414
Unpaid Principal Balance | 8,573 |  | 8,573 |  | 8,102
Impaired Loans Without Recorded Allowance [Member] | Land And Acquisition [Member] |  |  |  |  |
Financing Receivable, Recorded Investment [Line Items] |  |  |  |  |
Recorded Investment | 0 |  | 0 |  | 0
Unpaid Principal Balance | 0 |  | 0 |  | 0
Impaired Loans Without Recorded Allowance [Member] | Residential Construction [Member] |  |  |  |  |
Financing Receivable, Recorded Investment [Line Items] |  |  |  |  |
Recorded Investment | 0 |  | 0 |  | 336
Unpaid Principal Balance | 0 |  | 0 |  | 336
Impaired Loans Without Recorded Allowance [Member] | Income Property Multifamily Construction [Member] |  |  |  |  |
Financing Receivable, Recorded Investment [Line Items] |  |  |  |  |
Recorded Investment | 0 |  | 0 |  | 0
Unpaid Principal Balance | 0 |  | 0 |  | 0
Impaired Loans Without Recorded Allowance [Member] | Owner Occupied Construction [Member] |  |  |  |  |
Financing Receivable, Recorded Investment [Line Items] |  |  |  |  |
Recorded Investment | 4,050 |  | 4,050 |  | 0
Unpaid Principal Balance | 4,050 |  | 4,050 |  | 0
Impaired Loans Without Recorded Allowance [Member] | Consumer Portfolio Segment [Member] |  |  |  |  |
Financing Receivable, Recorded Investment [Line Items] |  |  |  |  |
Recorded Investment | 773 |  | 773 |  | 751
Unpaid Principal Balance | $ 914 |  | $ 914 |  | $ 833

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