NOTES PAYABLE AND DEBT AND FINANCING ARRANGEMENTS (Detail)	6 Months Ended	7 Months Ended	12 Months Ended								12 Months Ended		12 Months Ended
	Jun. 22, 2010 USD ($)	Aug. 03, 2010 USD ($)	Dec. 31, 2011 USD ($)	Dec. 31, 2009 USD ($)	Dec. 31, 2009 GBP (£)	Dec. 31, 2008 USD ($)	Dec. 31, 2010 USD ($)	Dec. 31, 2011 Revolving Credit Facilities [Member] USD ($)	Dec. 31, 2011 Revolving Credit Facilities [Member] 2007 Credit Agreement [Member] USD ($)	Dec. 31, 2011 Secured Debt [Member] USD ($)	Dec. 31, 2011 Relating To Settlment Of Purchase Contracts Common Class A [Member]	Dec. 31, 2011 Line of Credit [Member] USD ($)	Dec. 31, 2011 Secured Credit Agreement [Member] USD ($)	Dec. 31, 2011 Senior Notes [Member] USD ($)	Dec. 31, 2011 Common Class A [Member]	Dec. 31, 2010 Common Class A [Member]	Dec. 31, 2011 Unsecured Credit Agreement [Member] USD ($)	Dec. 31, 2009 2007 Credit Agreement [Member] USD ($)
Line of Credit Facility, Remaining Borrowing Capacity										$ 1,000,000,000
Debt Instrument, Interest Rate, Effective Percentage			6.50%
Proceeds from Issuance of Senior Long-term Debt			600,000,000											395,900,000
Required Statutory Capital and Surplus for Principal Operating Subsidiares			6,700,000,000				6,500,000,000
Number of Equity security units issued (in Shares)						23,000,000
Rate of Interest of Equity security units			10.75%
Proceeds from sale of Equity Security units						557,000,000
Face value of Equity security unit issued (in Dollars per share)			$ 25			$ 25
Equity Unit Purchase Contract Coupon Rate						2.50%
Investment Owned, Balance, Principal Amount						1,000
Equity Unit Note Coupon Rate			8.25%
Adjustments to Additional Paid in Capital, Warrant Issued						37,900,000
Payments of Stock Issuance Costs						18,000,000
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs						14,700,000
Senior Notes			575,000,000
Equity Security Unit Settlement Shares (in Shares)			1.3242
Stock Issued During Period, Shares, New Issues (in Shares)											30,456,600				30,457,000	0
Senior Notes Principal Amount			400,000,000
Line of Credit Facility, Increase, Additional Borrowings			500,000,000
Line of Credit Facility, Amount Outstanding								3,000,000,000	4,000,000,000
Line of Credit Facility, Maximum Borrowing Capacity												1,000,000,000
Line of credit facility terminated	2,300,000	100,000,000	75,000
Letter of credit facility				750,000,000													1,350,000,000	750,000,000
Maximum Issuance Of Letters Of Credit													650,000,000				1,000,000,000
Letter of credit facility terminated (in Pounds)					£ 450,000,000