Consolidated Statements Of Comprehensive Income (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Consolidated Statements Of Comprehensive Income [Abstract]
Net income (loss)	$ (9.7)	$ 52.3	$ (12.2)	$ 96.4
Available-for-sale securities:
Net appreciation during the period	6.2	99.1	43.7	220.5
Portion of other-than-temporary impairment losses transferred from other comprehensive income	0.8	2.3	6.2	6.6
(Provision) benefit for deferred income taxes	9.7	(25.9)	10.5	(57.4)
Total available-for-sale securities	16.7	75.5	60.4	169.7
Derivative instruments:
Net appreciation (depreciation) during the period	0.1		(1.8)
(Provision) benefit for deferred income taxes	(0.1)		0.6
Total derivative instruments			(1.2)
Amortization recognized as net periodic benefit costs:
Net actuarial loss	3.9	4.3	11.6	12.9
Prior service cost	(1.3)	(1.5)	(3.9)	(4.4)
Transition asset		(0.4)		(1.2)
Total amortization recognized as net periodic benefit costs	2.6	2.4	7.7	7.3
Provision for deferred income taxes	(0.9)	(0.9)	(2.7)	(2.6)
Total pension and postretirement benefits	1.7	1.5	5.0	4.7
Cumulative foreign currency translation adjustment:
Amount recognized as cumulative foreign currency translation during the period	(14.5)		(14.5)
Benefit (provision) for deferred income taxes	5.1		5.1
Total cumulative foreign currency translation adjustment	(9.4)		(9.4)
Other comprehensive income	9.0	77.0	54.8	174.4
Comprehensive income (loss)	$ (0.7)	$ 129.3	$ 42.6	$ 270.8