Income Taxes (Details) (USD $)	3 Months Ended	12 Months Ended					95 Months Ended	12 Months Ended	82 Months Ended	1 Months Ended	12 Months Ended
	Mar. 31, 2011	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2010 Convertible Notes - due February 7, 2031 [Member]	Dec. 31, 2009 Convertible Notes - due February 7, 2031 [Member]	Dec. 31, 2008 Convertible Notes - due February 7, 2031 [Member]	Dec. 31, 2009 Convertible Notes - due July 31, 2032 [Member]	Dec. 31, 2008 Convertible Notes - due July 31, 2032 [Member]	Jun. 30, 2010 Convertible Notes - due July 1, 2038 [Member]	Dec. 31, 2010 Convertible Notes - due July 1, 2038 [Member]
Income Before Income Taxes [Abstract]
Income before income taxes, Domestic		$ 581,000,000	$ 573,200,000	$ 598,800,000
Income before income taxes, International		968,000,000	777,200,000	675,400,000
INCOME BEFORE INCOME TAXES AND INCOME FROM EQUITY METHOD INVESTMENTS		1,549,000,000	1,350,400,000	1,274,200,000
Income Tax Expense [Abstract]
Income tax expense, current, Federal		158,600,000	107,200,000	58,200,000
Income tax expense, current, State and local		14,400,000	11,700,000	11,800,000
Income tax expense, current, International		239,500,000	233,100,000	198,500,000
Income tax expense, current		412,500,000	352,000,000	268,500,000
Income tax expense, deferred, Federal		83,600,000	98,900,000	146,900,000
Income tax expense, deferred, State and local		4,900,000	3,600,000	14,200,000
Income tax expense, deferred, International		4,800,000	5,700,000	4,000,000
Income tax expense, deferred		93,300,000	108,200,000	165,100,000
Income tax expense		505,800,000	460,200,000	433,600,000
Reconciliation from the Statutory U.S. Federal Income Tax Rate to Effective Tax Rate [Abstract]
Effective income tax rate reconciliation, Statutory U.S. federal income tax rate		35.00%	35.00%	35.00%
Effective income tax rate reconciliation, State and local taxes on income, net of federal income tax benefit		0.80%	0.70%	1.30%
Effective income tax rate reconciliation, Remeasurement gain Clemenger Group, tax rate differential		(2.60%)	0.00%	0.00%
Effective income tax rate reconciliation, International subsidiaries’ tax rate differentials		(1.40%)	(2.10%)	(2.70%)
Effective income tax rate reconciliation, Other		0.90%	0.50%	0.40%
Effective income tax rate reconciliation, Effective rate		32.70%	34.10%	34.00%
Tax benefit related to charges incurred in connection with repositioning actions	(39,500,000)
Tax provision related to remeasurement gain	2,800,000
Tax accrual for agreed upon adjustments to income tax returns currently under examination	9,000,000
Unrecognized Tax Benefits, Penalties and Interest [Abstract]
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense		2,800,000	3,900,000	3,800,000
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued		10,700,000	13,000,000
Components of Deferred Tax Assets and Liabilities [Abstract]
Deferred tax assets, Compensation and severance		291,500,000	257,600,000
Deferred tax assets, Tax loss and credit carryforwards		156,300,000	112,600,000
Deferred tax assets, Basis differences arising from acquisitions		37,200,000	23,800,000
Deferred tax assets, Basis differences from short-term assets and liabilities		33,600,000	27,700,000
Deferred tax assets, Other		19,800,000	9,800,000
Deferred tax assets		538,400,000	431,500,000
Deferred tax assets, Valuation allowance		(24,900,000)	(24,600,000)
Deferred tax assets, Net deferred tax assets		513,500,000	406,900,000
Deferred tax liabilities, Basis differences arising from investments		11,100,000	6,700,000
Deferred tax liabilities, Unremitted foreign earnings		143,200,000	85,000,000
Deferred tax liabilities, Financial instruments		480,300,000	458,200,000
Deferred tax liabilities, Goodwill and intangible assets		577,400,000	449,200,000
Deferred tax liabilities		1,212,000,000	999,100,000
Net deferred tax assets (liabilities)		(698,500,000)	(592,200,000)
Net deferred tax assets and (liabilities), classified [Abstract]
Other current assets - Deferred taxes		169,100,000	141,300,000
Deferred tax assets		0	14,200,000
Long-term deferred tax liabilities		(867,600,000)	(747,700,000)
Convertible debt, repayments of convertible debt					5,700,000	841,200,000	3,000,000	474,300,000	173,000,000	60,800,000	60,800,000
Convertible debt, repayments of convertible debt, deferred tax liability			12,000,000	328,000,000
Reduction of deferred tax assets, utilization of tax loss and credit carryforwards			30,500,000
Reduction of deferred tax assets, tax loss and credit carryforwards unable to be utilized			39,000,000
Tax loss and credit carryforwards, expiration dates		5 to 20 years
Cumulative undistributed earnings of certain foreign subsidiaries indefinitely reinvested		1,000,000,000
Cumulative undistributed earnings of certain foreign subsidiaries not deemed to be indefinitely reinvested		1,500,000,000
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Unrecognized tax benefits, Balance January 1	165,100,000	165,100,000	202,800,000
Unrecognized tax benefits, Current year tax positions		12,200,000	11,400,000
Unrecognized tax benefits, Prior year tax positions		12,500,000	18,300,000
Unrecognized tax benefits, Reduction of prior year tax positions		(14,800,000)	(38,800,000)
Unrecognized tax benefits, Settlements		(16,700,000)	(24,100,000)
Unrecognized tax benefits, Lapse of statute of limitations		0	(2,600,000)
Unrecognized tax benefits, Foreign currency translation		(500,000)	(1,900,000)
Unrecognized tax benefits, Balance December 31		157,800,000	165,100,000	202,800,000
Unrecognized tax benefits that would impact effective tax rate		$ 62,400,000	$ 72,400,000