FAIR VALUE OF FINANCIAL INSTRUMENTS - UNREALIZED GAINS AND LOSSES (DETAILS) (USD $) In Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2011	Dec. 31, 2010
Schedule of Available-for-sale Securities [Line Items]
Available For Sale Securities Credit Loss Previously Recorded In Earnings	$ (2.2)
Credit Losses	0	0
Unrealized Gains in AOCL	15.1
Unrealized Losses - Less Than 12 Months	(1.0)
Unrealized Losses - Greater Than 12 Months	(3.2)
Unrealized Losses - Total Unrealized Losses	4.2
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Available-for-sale Securities	2.2
Unrealized Losses - Net Unrealized Losses in AOCL	(2.0)
Net Unrealized Gains/(Losses) in AOCL	13.1
Fair Value of Securities with Unrealized Losses	184.1
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	(2.0)
US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized Gains in AOCL	4.6
Unrealized Losses - Less Than 12 Months	(0.1)
Unrealized Losses - Greater Than 12 Months	0
Unrealized Losses - Total Unrealized Losses	(0.1)
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Available-for-sale Securities	0
Unrealized Losses - Net Unrealized Losses in AOCL	(0.1)
Net Unrealized Gains/(Losses) in AOCL	4.5
Fair Value of Securities with Unrealized Losses	18.1
Asset-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized Gains in AOCL	1.1
Unrealized Losses - Less Than 12 Months	(0.6)
Unrealized Losses - Greater Than 12 Months	(3.2)
Unrealized Losses - Total Unrealized Losses	(3.8)
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Available-for-sale Securities	(2.2)
Unrealized Losses - Net Unrealized Losses in AOCL	(1.6)
Net Unrealized Gains/(Losses) in AOCL	(0.5)
Fair Value of Securities with Unrealized Losses	56.8
Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized Gains in AOCL	9.4
Unrealized Losses - Less Than 12 Months	(0.3)
Unrealized Losses - Greater Than 12 Months	0
Unrealized Losses - Total Unrealized Losses	(0.3)
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Available-for-sale Securities	0
Unrealized Losses - Net Unrealized Losses in AOCL	(0.3)
Net Unrealized Gains/(Losses) in AOCL	9.1
Fair Value of Securities with Unrealized Losses	$ 109.2