Discontinued Operations - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Mortgage Loan Repurchase Claims Outstanding	$ 101.7		$ 101.7
Discontinued Operations
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Repurchase reserve	5.8		5.8		6.5
Recoveries of provisions for repurchases	0.3	0.3	0.8	0.8
Outstanding Claims For More Than Six Years
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Mortgage Loan Repurchase Claims Outstanding	63.1		63.1
Mortgage Loan Repurchase Claims Outstanding, Percentage	62.00%		62.00%
Outstanding Claims For More Than Four Years But Less Than Six Years
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Mortgage Loan Repurchase Claims Outstanding	10.3		10.3
Mortgage Loan Repurchase Claims Outstanding, Percentage	10.20%		10.20%
Outstanding Claims For More Than Two Years But Less Than Four Years
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Mortgage Loan Repurchase Claims Outstanding	$ 28.3		$ 28.3
Mortgage Loan Repurchase Claims Outstanding, Percentage	27.80%		27.80%