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Reinsurance - Coverage and retention (Details) - Variable Interest Entity, Not Primary Beneficiary $ in Thousands | 12 Months Ended
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Dec. 31, 2020 USD ($)
Variable Interest Entity [Line Items] |  |
Initial Coverage at Issuance | $ 5,909,497 |
Current Coverage | 3,967,473 |
Remaining Retention, Net | $ 2,576,354 |
Amortization period | ten |
Bellemeade 2017-1 Ltd |  |
Variable Interest Entity [Line Items] |  |
Initial Coverage at Issuance | $ 368,114 | [1]
Current Coverage | 145,573 | [1]
Remaining Retention, Net | 125,953 | [1]
Bellemeade 2018-1 Ltd |  |
Variable Interest Entity [Line Items] |  |
Initial Coverage at Issuance | 374,460 | [2]
Current Coverage | 250,095 | [2]
Remaining Retention, Net | 123,690 | [2]
Bellemeade 2018-2 Ltd |  |
Variable Interest Entity [Line Items] |  |
Initial Coverage at Issuance | 653,278 | [3]
Current Coverage | 108,395 | [3]
Remaining Retention, Net | 305,606 | [3]
Bellemeade 2018-3 Ltd |  |
Variable Interest Entity [Line Items] |  |
Initial Coverage at Issuance | 506,110 | [4]
Current Coverage | 302,563 | [4]
Remaining Retention, Net | 129,874 | [4]
Bellemeade 2019-1 Ltd |  |
Variable Interest Entity [Line Items] |  |
Initial Coverage at Issuance | 341,790 | [5]
Current Coverage | 219,256 | [5]
Remaining Retention, Net | 116,530 | [5]
Bellemeade 2019-2 Ltd |  |
Variable Interest Entity [Line Items] |  |
Initial Coverage at Issuance | 621,022 | [6]
Current Coverage | 398,316 | [6]
Remaining Retention, Net | 162,457 | [6]
Bellemeade 2019-3 Ltd |  |
Variable Interest Entity [Line Items] |  |
Initial Coverage at Issuance | 700,920 | [7]
Current Coverage | 528,084 | [7]
Remaining Retention, Net | 181,036 | [7]
Bellemeade 2019-4 Ltd |  |
Variable Interest Entity [Line Items] |  |
Initial Coverage at Issuance | 577,267 | [8]
Current Coverage | 468,737 | [8]
Remaining Retention, Net | 118,102 | [8]
Bellemeade 2020-1 Ltd. |  |
Variable Interest Entity [Line Items] |  |
Initial Coverage at Issuance | 528,540 | [9]
Current Coverage | 308,458 | [9]
Remaining Retention, Net | 754,782 | [9]
Bellemeade 2020-2 Ltd |  |
Variable Interest Entity [Line Items] |  |
Initial Coverage at Issuance | 449,167 | [10]
Current Coverage | 449,167 | [10]
Remaining Retention, Net | 239,278 | [10]
Bellemeade 2020-3 Ltd |  |
Variable Interest Entity [Line Items] |  |
Initial Coverage at Issuance | 451,816 | [11]
Current Coverage | 451,816 | [11]
Remaining Retention, Net | 171,580 | [11]
Bellemeade 2020-4 Ltd |  |
Variable Interest Entity [Line Items] |  |
Initial Coverage at Issuance | 337,013 | [12]
Current Coverage | 337,013 | [12]
Remaining Retention, Net | 147,466 | [12]
Funded By VIE | Bellemeade 2020-1 Ltd. |  |
Variable Interest Entity [Line Items] |  |
Initial Coverage at Issuance | 450,000 |
Funded By VIE | Bellemeade 2020-2 Ltd |  |
Variable Interest Entity [Line Items] |  |
Initial Coverage at Issuance | 423,000 |
Funded By VIE | Bellemeade 2020-3 Ltd |  |
Variable Interest Entity [Line Items] |  |
Initial Coverage at Issuance | 418,000 |
Funded By VIE | Bellemeade 2020-4 Ltd |  |
Variable Interest Entity [Line Items] |  |
Initial Coverage at Issuance | 321,000 |
Directly provided capacity | Bellemeade 2020-1 Ltd. |  |
Variable Interest Entity [Line Items] |  |
Initial Coverage at Issuance | 79,000 |
Directly provided capacity | Bellemeade 2020-2 Ltd |  |
Variable Interest Entity [Line Items] |  |
Initial Coverage at Issuance | 26,000 |
Directly provided capacity | Bellemeade 2020-3 Ltd |  |
Variable Interest Entity [Line Items] |  |
Initial Coverage at Issuance | 34,000 |
Directly provided capacity | Bellemeade 2020-4 Ltd |  |
Variable Interest Entity [Line Items] |  |
Initial Coverage at Issuance | $ 16,000 |
[1] | Issued in October 2017, covering in-force policies issued between January 1, 2017 and June 30, 2017.
[2] | Issued in April 2018, covering in-force policies issued between July 1, 2017 and December 31, 2017.
[3] | Issued in August 2018, covering in-force policies issued between April 1, 2013 and December 31, 2015.
[4] | Issued in October 2018, covering in-force policies issued between January 1, 2018 and June 30, 2018.
[5] | Issued in March 2019, covering in-force policies primarily issued between 2005 to 2008 under United Guaranty Residential Insurance Company (“UGRIC”); as well as policies issued through 2015 under both UGRIC and Arch Mortgage Insurance Company.
[6] | Issued in April 2019, covering in-force policies issued between July 1, 2018 and December 31, 2018.
[7] | Issued in July 2019, covering in-force policies issued in 2016.
[8] | Issued in October 2019, covering in-force policies issued between January 1, 2019 and June 30, 2019.
[9] | Issued in June 2020, covering in-force policies issued between July 1, 2019 and December 31, 2019. $450 million was directly funded by Bellemeade 2020-1 Ltd. with an additional $79 million of capacity provided directly to Arch MI U.S. by a separate panel of reinsurers
[10] | Issued in September 2020, covering in-force policies issued between January 1, 2020 and May 31, 2020. $423 million was directly funded by Bellemeade 2020-2 Ltd. with an additional $26 million of capacity provided directly to Arch MI U.S. by a separate panel of reinsurers
[11] | Issued in November 2020, covering in-force policies issued between June 1, 2020 and August 31, 2020. $418 million was directly funded by Bellemeade 2020-3 Ltd. with an additional $34 million of capacity provided directly to Arch MI U.S. by a separate panel of reinsurers.
[12] | Issued in December 2020, covering in-force policies issued between July 1, 2019 and December 31, 2019. $321 million was directly funded by Bellemeade 2020-4 Ltd. with an additional $16 million of capacity provided directly to Arch MI U.S. by a separate panel of reinsurers

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