Business Acquired - Narrative (Details) (CMG Mortgage Insurance Company, USD $)	0 Months Ended	3 Months Ended
	Jan. 30, 2014	Mar. 31, 2014
Business Acquisition [Line Items]
Percentage of voting interests acquired	100.00%
Quota share agreement percentage		100.00%
Cash paid	$ 245,157,000
Contingent consideration, upper bound		136,300,000
Discount rate, percentage	15.00%
Contingent consideration liability	41,762,000	43,156,000
Goodwill	13,852,000
Goodwill, deferred tax asset		48,000,000
Stock Purchase Agreement (SPA)
Business Acquisition [Line Items]
Cash paid	160,600,000
Percentage of book value	80.00%
Asset Purchase Agreement (APA)
Business Acquisition [Line Items]
Cash paid	84,600,000
Maximum
Business Acquisition [Line Items]
Percentage of book value	150.00%
Extension period		3 years
Minimum
Business Acquisition [Line Items]
Extension period		1 year
New mortgage insurance business (post closing)
Business Acquisition [Line Items]
Quota share agreement percentage		20.00%
Quota share reinsurance agreement limit		$ 25,000,000,000