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Reinsurance (Details) - USD ($) |  | 3 Months Ended | 9 Months Ended |  |
--- | --- | --- | --- | --- | ---
Jul. 01, 2015 | Sep. 30, 2016 | Sep. 30, 2015 | Sep. 30, 2016 | Sep. 30, 2015 | Dec. 31, 2015 | Dec. 31, 2014
Reinsurance Disclosures [Abstract] |  |  |  |  |  |  |
Premiums earned - Direct |  | $ 270,718,000 | $ 252,951,000 | $ 789,671,000 | $ 738,870,000 |  |
Premiums earned - Assumed |  | 152,000 | 285,000 | 542,000 | 931,000 |  |
Premiums earned - Ceded |  | (33,494,000) | (14,002,000) | (100,040,000) | (69,771,000) |  |
Net premiums earned |  | 237,376,000 | 239,234,000 | 690,173,000 | 670,030,000 |  |
Losses incurred - Direct |  | 69,579,000 | 81,699,000 | 216,874,000 | 265,445,000 |  |
Losses incurred - Assumed |  | 241,000 | 425,000 | 681,000 | 1,191,000 |  |
Losses incurred - Ceded |  | (8,923,000) | (5,666,000) | (25,056,000) | (18,155,000) |  |
Net losses incurred |  | 60,897,000 | 76,458,000 | 192,499,000 | 248,481,000 |  |
Premiums Written and Earned [Abstract] |  |  |  |  |  |  |
Ceded losses incurred |  | 8,923,000 | 5,666,000 | 25,056,000 | 18,155,000 |  |
Reinsurance recoverable on loss reserves |  | 46,863,000 | 38,748,000 | $ 46,863,000 | 38,748,000 | $ 44,487,000 | $ 57,841,000
Period of existing captive reinsurance agreement |  |  |  | 10 years |  |  |
Reinsurance recoverable on loss reserves related to captive agreements |  | 20,000,000 |  | $ 20,000,000 |  | 34,000,000 |
Fair value of trust fund assets under captive agreements |  | 94,000,000 |  | 94,000,000 |  | 137,000,000 |
Quota Share Reinsurance Agreement, 2013 |  |  |  |  |  |  |
Reinsurance Disclosures [Abstract] |  |  |  |  |  |  |
Losses incurred - Ceded |  |  | 0 |  | (6,060,000) |  |
Premiums Written and Earned [Abstract] |  |  |  |  |  |  |
Ceded premiums written, net of profit commission |  |  | (69,410,000) |  | (11,355,000) |  |
Ceded premiums earned, net of profit commission |  |  | (11,568,000) |  | 35,999,000 |  |
Ceded losses incurred |  |  | 0 |  | 6,060,000 |  |
Ceding commissions |  |  | (11,568,000) |  | 10,235,000 |  |
Profit commission |  |  | 11,568,000 |  | 62,525,000 |  |
Quota Share Reinsurance Agreement, 2015 |  |  |  |  |  |  |
Reinsurance Disclosures [Abstract] |  |  |  |  |  |  |
Losses incurred - Ceded |  | (7,432,000) | (4,236,000) | (22,015,000) | (4,236,000) |  |
Effects of Reinsurance [Line Items] |  |  |  |  |  |  |
Contingent termination fee | $ 0 |  |  |  |  |  |
Threshold for private mortgage insurer eligibility requirements for termination election (less than) | 90.00% |  |  |  |  |  |
Quota share for all policies covered | 30.00% |  |  |  |  |  |
Ceding commission, percentage | 20.00% |  |  |  |  |  |
Loss ratio threshold for profit commissions | 60.00% |  |  |  |  |  |
Premiums Written and Earned [Abstract] |  |  |  |  |  |  |
Ceded premiums written, net of profit commission |  | 31,707,000 | 22,626,000 | 93,334,000 | 22,626,000 |  |
Ceded premiums earned, net of profit commission |  | 31,707,000 | 22,626,000 | 93,334,000 | 22,626,000 |  |
Ceded losses incurred |  | 7,432,000 | 4,236,000 | 22,015,000 | 4,236,000 |  |
Ceding commissions |  | 12,137,000 | 9,195,000 | 35,659,000 | 9,195,000 |  |
Profit commission |  | 28,981,000 | $ 23,347,000 | 84,963,000 | $ 23,347,000 |  |
Reinsurance recoverable on loss reserves |  | $ 27,000,000 |  | $ 27,000,000 |  | $ 11,000,000 |

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- Definition The known and estimated amount recoverable, related to captive agreements, as of the balance sheet date from reinsurers for claims paid or incurred by the ceding insurer and associated claims settlement expenses, including estimated amounts for claims incurred but not reported, and policy benefits, net of any related valuation allowance. + References No definition available. + Details
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