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Commercial Loans - Geographic Concentrate of Commercial Loans Recorded on Consolidated Balance Sheet (Detail) | 12 Months Ended
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Dec. 31, 2015 | Dec. 31, 2014
Commercial Loans Held For Sale |  |
Concentration Risk [Line Items] |  |
Concentration risk percentage | 100.00% | 100.00%
Commercial Loans Held For Sale | Nevada |  |
Concentration Risk [Line Items] |  |
Concentration risk percentage | 45.00% | 0.00%
Commercial Loans Held For Sale | Virginia |  |
Concentration Risk [Line Items] |  |
Concentration risk percentage | 26.00% | 0.00%
Commercial Loans Held For Sale | Florida |  |
Concentration Risk [Line Items] |  |
Concentration risk percentage | 18.00% | 0.00%
Commercial Loans Held For Sale | Illinois |  |
Concentration Risk [Line Items] |  |
Concentration risk percentage | 11.00% | 0.00%
Commercial Loans Held For Sale | California |  |
Concentration Risk [Line Items] |  |
Concentration risk percentage | 0.00% | 6.00%
Commercial Loans Held For Sale | New York |  |
Concentration Risk [Line Items] |  |
Concentration risk percentage | 0.00% | 0.00%
Commercial Loans Held For Sale | Michigan |  |
Concentration Risk [Line Items] |  |
Concentration risk percentage | 0.00% | 18.00%
Commercial Loans Held For Sale | Washington, District of Columbia |  |
Concentration Risk [Line Items] |  |
Concentration risk percentage | 0.00% | 25.00%
Commercial Loans Held For Sale | Colorado |  |
Concentration Risk [Line Items] |  |
Concentration risk percentage | 0.00% | 17.00%
Commercial Loans Held For Sale | Connecticut |  |
Concentration Risk [Line Items] |  |
Concentration risk percentage | 0.00% | 10.00%
Commercial Loans Held For Sale | Texas |  |
Concentration Risk [Line Items] |  |
Concentration risk percentage | 0.00% | 9.00%
Commercial Loans Held For Sale | Maryland |  |
Concentration Risk [Line Items] |  |
Concentration risk percentage | 0.00% | 7.00%
Commercial Loans Held For Sale | North Carolina |  |
Concentration Risk [Line Items] |  |
Concentration risk percentage | 0.00% | 0.00%
Commercial Loans Held For Sale | Other states |  |
Concentration Risk [Line Items] |  |
Concentration risk percentage | 0.00% | 8.00%
Concentration risk percentage per other state | 5.00% | 5.00%
Commercial Loans Held For Investment |  |
Concentration Risk [Line Items] |  |
Concentration risk percentage | 100.00% | 100.00%
Commercial Loans Held For Investment | Nevada |  |
Concentration Risk [Line Items] |  |
Concentration risk percentage | 0.00% | 0.00%
Commercial Loans Held For Investment | Virginia |  |
Concentration Risk [Line Items] |  |
Concentration risk percentage | 0.00% | 0.00%
Commercial Loans Held For Investment | Florida |  |
Concentration Risk [Line Items] |  |
Concentration risk percentage | 10.00% | 17.00%
Commercial Loans Held For Investment | Illinois |  |
Concentration Risk [Line Items] |  |
Concentration risk percentage | 0.00% | 0.00%
Commercial Loans Held For Investment | California |  |
Concentration Risk [Line Items] |  |
Concentration risk percentage | 22.00% | 19.00%
Commercial Loans Held For Investment | New York |  |
Concentration Risk [Line Items] |  |
Concentration risk percentage | 19.00% | 18.00%
Commercial Loans Held For Investment | Michigan |  |
Concentration Risk [Line Items] |  |
Concentration risk percentage | 10.00% | 8.00%
Commercial Loans Held For Investment | Washington, District of Columbia |  |
Concentration Risk [Line Items] |  |
Concentration risk percentage | 0.00% | 0.00%
Commercial Loans Held For Investment | Colorado |  |
Concentration Risk [Line Items] |  |
Concentration risk percentage | 0.00% | 0.00%
Commercial Loans Held For Investment | Connecticut |  |
Concentration Risk [Line Items] |  |
Concentration risk percentage | 0.00% | 0.00%
Commercial Loans Held For Investment | Texas |  |
Concentration Risk [Line Items] |  |
Concentration risk percentage | 5.00% | 0.00%
Commercial Loans Held For Investment | Maryland |  |
Concentration Risk [Line Items] |  |
Concentration risk percentage | 0.00% | 0.00%
Commercial Loans Held For Investment | North Carolina |  |
Concentration Risk [Line Items] |  |
Concentration risk percentage | 0.00% | 6.00%
Commercial Loans Held For Investment | Other states |  |
Concentration Risk [Line Items] |  |
Concentration risk percentage | 34.00% | 32.00%
Concentration risk percentage per other state | 5.00% | 5.00%

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