Reinsurance - Single Premium QSR Program (Details) - Radian Guaranty - USD ($) $ in Millions				33 Months Ended	36 Months Ended
	Jan. 01, 2020	Jan. 01, 2018	Jan. 01, 2016	Dec. 31, 2015	Dec. 31, 2017	Jun. 30, 2022	Dec. 31, 2021
2020 Single Premium QSR Agreement
Ceding commission %	25.00%
RIF ceded						$ 2,085	$ 2,198
2020 Single Premium QSR Agreement | Revenue Benchmark | Product Concentration Risk
Quota share %	65.00%
2018 Single Premium QSR Agreement
Ceding commission %		25.00%
RIF ceded						968	1,117
2018 Single Premium QSR Agreement | Revenue Benchmark | Product Concentration Risk
Quota share %		65.00%
2016 Single Premium QSR Agreement
Ceding commission %			25.00%
RIF ceded						$ 1,612	$ 1,913
Maximum | 2020 Single Premium QSR Agreement
Profit commission %	56.00%
Maximum | 2018 Single Premium QSR Agreement
Profit commission %		56.00%
Maximum | 2016 Single Premium QSR Agreement
Profit commission %			55.00%
Maximum | 2016 Single Premium QSR Agreement | Revenue Benchmark | Product Concentration Risk
Quota share %			65.00%	35.00%
Minimum | 2016 Single Premium QSR Agreement | Revenue Benchmark | Product Concentration Risk
Quota share %			20.00%		35.00%