Guarantor Condensed Consolidating Financial Statements (Condensed Consolidating Balance Sheets) (Details) (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2010	Dec. 31, 2009
Assets held for policyholders	$ 1,255.3	$ 1,295.4
Total current assets	3,982.4	4,274.5
Goodwill	6,857.5	6,980.2
Total assets	19,737.8	20,444.1
Policyholder payables	1,255.3	1,295.4
Total current liabilities	3,113.2	3,264.5
Non-current liabilities	(7,657.1)	(7,818.7)
Total liabilities	10,770.3	11,083.2
Total equity attributable to common shareholders	7,949.1	8,264.6
Equity attributable to noncontrolling interests in consolidated entities	1,018.4	1,096.3
Total equity	8,967.5	9,360.9	8,846.2	7,620.8
Total liabilities and equity	19,737.8	20,444.1
Guarantors [Member]
Assets held for policyholders	0
Other current assets	239.3	(175.7)
Total current assets	239.3	(175.7)
Goodwill	2,323.2	(2,322.9)
Investments in subsidiaries	1,200.6	(1,333.8)
Other non-current assets	574.7	(557.0)
Total assets	4,337.8	(4,389.4)
Policyholder payables	0
Other current liabilities	90.4	(112.5)
Total current liabilities	90.4	(112.5)
Intercompany balances	885.2	(1,299.8)
Non-current liabilities	719.6	597.0
Total liabilities	1,695.2	(2,009.3)
Total equity attributable to common shareholders	2,642.6	(2,380.1)
Equity attributable to noncontrolling interests in consolidated entities	0
Total equity	2,642.6	(2,380.1)
Total liabilities and equity	4,337.8	(4,389.4)
Non-Guarantors [Member]
Assets held for policyholders	1,255.3	(1,295.4)
Other current assets	2,470.4	(2,766.7)
Total current assets	3,725.7	(4,062.1)
Goodwill	4,096.4	(4,216.5)
Investments in subsidiaries	7.5	(5.5)
Other non-current assets	8,314.9	(8,625.0)
Total assets	16,144.5	(16,909.1)
Policyholder payables	1,255.3	(1,295.4)
Other current liabilities	1,532.8	(1,850.4)
Total current liabilities	2,788.1	(3,145.8)
Intercompany balances	(1,329.9)	1,449.6
Non-current liabilities	6,406.9	6,476.0
Total liabilities	7,865.1	(8,172.2)
Total equity attributable to common shareholders	7,261.0	(7,640.6)
Equity attributable to noncontrolling interests in consolidated entities	1,018.4	(1,096.3)
Total equity	8,279.4	(8,736.9)
Total liabilities and equity	16,144.5	(16,909.1)
Issuer [Member]
Assets held for policyholders	0
Other current assets	4.4	(3.0)
Total current assets	4.4	(3.0)
Goodwill	437.9	(440.8)
Investments in subsidiaries	4,961.3	(4,766.1)
Other non-current assets	5.3	(4.5)
Total assets	5,408.9	(5,214.4)
Policyholder payables	0
Other current liabilities	234.0	(5.5)
Total current liabilities	234.0	(5.5)
Intercompany balances	43.4	22.1
Non-current liabilities	530.6	745.7
Total liabilities	808.0	(729.1)
Total equity attributable to common shareholders	4,600.9	(4,485.3)
Equity attributable to noncontrolling interests in consolidated entities	0
Total equity	4,600.9	(4,485.3)
Total liabilities and equity	5,408.9	(5,214.4)
Parent Company [Member]
Assets held for policyholders	0
Other current assets	13.0	(33.7)
Total current assets	13.0	(33.7)
Goodwill	0
Investments in subsidiaries	8,335.1	(8,400.6)
Other non-current assets	3.0	(2.9)
Total assets	8,351.1	(8,437.2)
Policyholder payables	0
Other current liabilities	0.7	(0.7)
Total current liabilities	0.7	(0.7)
Intercompany balances	401.3	(171.9)
Non-current liabilities	0
Total liabilities	402.0	(172.6)
Total equity attributable to common shareholders	7,949.1	(8,264.6)
Equity attributable to noncontrolling interests in consolidated entities	0
Total equity	7,949.1	(8,264.6)
Total liabilities and equity	8,351.1	(8,437.2)
Adjustments [Member]
Assets held for policyholders	0
Other current assets	0
Total current assets	0
Goodwill	0
Investments in subsidiaries	(14,504.5)	14,506.0
Other non-current assets	0
Total assets	(14,504.5)	14,506.0
Policyholder payables	0
Other current liabilities	0
Total current liabilities	0
Intercompany balances	0
Non-current liabilities	0
Total liabilities	0
Total equity attributable to common shareholders	(14,504.5)	14,506.0
Equity attributable to noncontrolling interests in consolidated entities	0
Total equity	(14,504.5)	14,506.0
Total liabilities and equity	(14,504.5)	14,506.0
Consolidated [Member]
Assets held for policyholders	1,255.3	(1,295.4)
Other current assets	2,727.1	(2,979.1)
Total current assets	3,982.4	(4,274.5)
Goodwill	6,857.5	(6,980.2)
Investments in subsidiaries	0
Other non-current assets	8,897.9	(9,189.4)
Total assets	19,737.8	(20,444.1)
Policyholder payables	1,255.3	(1,295.4)
Other current liabilities	1,857.9	(1,969.1)
Total current liabilities	3,113.2	(3,264.5)
Intercompany balances	0
Non-current liabilities	7,657.1	7,818.7
Total liabilities	10,770.3	(11,083.2)
Total equity attributable to common shareholders	7,949.1	(8,264.6)
Equity attributable to noncontrolling interests in consolidated entities	1,018.4	(1,096.3)
Total equity	8,967.5	(9,360.9)
Total liabilities and equity	$ 19,737.8	$ (20,444.1)