Schedule II Financial Information of Registrant Parent Company Only Financial Information (Details) (USD $)	12 Months Ended							1 Months Ended				1 Months Ended	12 Months Ended					1 Months Ended	12 Months Ended								1 Months Ended	12 Months Ended								1 Months Ended	12 Months Ended			1 Months Ended		1 Months Ended	7 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Senior Notes Due 2017	Dec. 31, 2013 Senior Notes Due 2015	Jun. 01, 2005 Senior Notes Due 2015	Dec. 31, 2013 Convertible Senior Notes Due 2017	Nov. 30, 2010 Convertible Senior Notes Due 2017 Convertible Debt [Member]	Dec. 31, 2013 Convertible Senior Notes Due 2017 Convertible Debt [Member]	Dec. 31, 2012 Convertible Senior Notes Due 2017 Convertible Debt [Member]	Nov. 15, 2010 Convertible Senior Notes Due 2017 Convertible Debt [Member]	Feb. 15, 2013 Senior Notes Due 2013	Dec. 31, 2012 Senior Notes Due 2013	Dec. 31, 2013 Senior Notes Due 2013	Feb. 01, 2003 Senior Notes Due 2013	Dec. 31, 2013 Convertible Senior Notes Due 2019	Dec. 31, 2013 Convertible Senior Notes Due 2019 Convertible Debt [Member]	Dec. 31, 2011 Parent Company	Dec. 31, 2013 Parent Company		Dec. 31, 2012 Parent Company		Dec. 31, 2011 Parent Company		Dec. 31, 2013 Subsidiaries [Member]	Dec. 31, 2012 Subsidiaries [Member]	Dec. 31, 2011 Radian Guaranty [Member]	Dec. 31, 2013 Radian Guaranty [Member]	Dec. 31, 2012 Radian Guaranty [Member]	Dec. 31, 2011 Radian Guaranty [Member]	Dec. 31, 2013 RDN Investments [Member]	Dec. 31, 2013 Radian Mortgage Services [Member]	Dec. 31, 2012 Enhance Financial Services [Member]	Dec. 31, 2013 Radian Mortgage Reinsurance [Member]	Dec. 31, 2012 Radian Mortgage Reinsurance [Member]	Feb. 28, 2014 Subsequent Event [Member] Radian Guaranty [Member]	Dec. 31, 2013 Requirement Per Fannie Mae Approval [Member] Radian Guaranty [Member]	Dec. 31, 2013 Debt Due 2015 Exchange Senior Notes Due 2017	Dec. 31, 2013 Debt Due 2015 Exchange Senior Notes Due 2015	Mar. 31, 2013 Debt Offering 2013 [Member] Convertible Senior Notes Due 2019 Convertible Debt [Member]	Dec. 31, 2013 Debt Offering 2013 [Member] Convertible Senior Notes Due 2019 Convertible Debt [Member]	Mar. 31, 2013 Common Stock Stock Offering 2013 [Member]	Sep. 30, 2013 Common Stock Stock Offering 2013 [Member]
Supplemental Notes [Abstract]
Restricted Funds Included In Short Term Investments																			$ 41,600,000		$ 55,600,000
Restricted Cash Held As Collateral For Insurance Trust Agreement																			100,000		400,000
Total Operating Expenses and Interest Expense Allocated to Subsidiaries From Parent Company																			140,000,000		93,200,000		100,700,000
Cash Dividends Paid to Parent Company by Consolidated Subsidiaries	7,600,000
Capital Contributions																			233,391,000	[1]	100,384,000	[1]	50,587,000	[1]	313,900,000	100,400,000		230,000,000	100,000,000	30,000,000	80,500,000	2,900,000	20,100,000	100,000	100,000	100,000,000	400,000
Tax Payments to Parent from Subsidiaries																			500,000		36,800,000
Cash Distributed From Parent to Consolidated Subsidiary																													300,000
Income Taxes, Parent Refund To Subsidiary, Net of Intercompany Receipts																										67,000,000
Consolidation, Wholly Owned Subsidiary, Parent Ownership Interest Changes, Transfer of Interest by Parent																											16,600,000
Payments for (Proceeds from) Businesses and Interest in Affiliates																		5,700,000
Redemption of long-term debt												79,400,000	170,600,000																										195,500,000
Price Per Principal Amount Tendered for Repurchase of Long Term Debt Through Modified Dutch Auction Tender Offer													900
Principal Amount of Note Used as Basis for Determining Tender Cap Range of Purchase													1,000
Debt Instrument, Face Amount						250,000,000					450,000,000				250,000,000		400,000,000																					195,500,000		400,000,000
Debt Instrument, Interest Rate, Stated Percentage				9.00%	5.375%		3.00%				3.00%			5.625%		2.25%																						9.00%	5.375%	2.25%	2.25%
Proceeds/payments related to issuance or exchange of debt, net								391,300,000											377,783,000		0		0																	389,800,000
Gains (Losses) on Extinguishment of Debt													16,200,000						3,952,000		(16,175,000)		0															(4,000,000)
Percent of Stock With Ordinary Voting Rights That the Company Must Retain In Order to Make Any Capital Stock Transactions Under Debt Covenant Agreement				80.00%	80.00%
Stock Issued During Period, Shares, New Issues																																										39,100,000.0
Sale of Stock, Price Per Share																																										$ 8.00
Issuance of common stock	299,410,000	0	0																299,410,000		0		0																				299,400,000
Long-term Debt, Maturities, Repayments of Principal in Year Two																			54,499,000
Long-term Debt, Maturities, Repayments of Principal in Year Four																			645,501,000
Long-term Debt, Maturities, Repayments of Principal after Year Five																			400,000,000
Long-term Debt, Gross									$ 450,000,000	$ 450,000,000							$ 400,000,000		$ 1,100,000,000																					$ 400,000,000

[1] See Note D.