Income Taxes (Details) (USD $)	3 Months Ended		12 Months Ended			24 Months Ended	12 Months Ended
	Jun. 30, 2013	Mar. 31, 2011	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010 Convertible Debt [Member]	Dec. 31, 2013 Minimum [Member]	Dec. 31, 2013 Maximum [Member]
Income Before Income Taxes [Abstract]
Income before income taxes, Domestic			$ 629,400,000	$ 683,500,000	$ 581,000,000
Income before income taxes, International			1,031,500,000	976,100,000	968,000,000
Income Before Income Taxes and Income (Loss) From Equity Method Investments			1,660,900,000	1,659,600,000	1,549,000,000
Income Tax Expense [Abstract]
Income tax expense, current, Federal			246,300,000	163,300,000	158,600,000
Income tax expense, current, State and local			30,600,000	40,100,000	14,400,000
Income tax expense, current, International			336,500,000	298,300,000	239,500,000
Income tax expense, current			613,400,000	501,700,000	412,500,000
Income tax expense, deferred, Federal			300,000	41,700,000	83,600,000
Income tax expense, deferred, State and local			(3,600,000)	4,700,000	4,900,000
Income tax expense, deferred, International			(44,900,000)	(21,000,000)	4,800,000
Income tax expense, deferred			(48,200,000)	25,400,000	93,300,000
Income tax expense			565,200,000	527,100,000	505,800,000
Reconciliation from the Statutory U.S. Federal Income Tax Rate to Effective Tax Rate [Abstract]
Statutory U.S. federal income tax rate			35.00%	35.00%	35.00%
State and local income taxes, net of federal income tax benefit			1.00%	1.70%	0.80%
Reduction of tax on unremitted foreign earnings due to legal reorganization			0.00%	(1.30%)	0.00%
Remeasurement gain Clemenger Group, tax rate differential			0.00%	0.00%	(2.60%)
International tax rate differentials			(3.00%)	(3.30%)	(1.40%)
Other			1.00%	(0.30%)	0.90%
Effective tax rate			34.00%	31.80%	32.70%
Effective tax rate, excluding merger expenses			33.60%
Reduction of income tax expense				53,000,000
Increase in income tax expense				16,000,000
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			1,600,000	2,500,000	2,800,000
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued			11,500,000	18,800,000
Deferred tax assets:
Compensation and severance			269,800,000	283,000,000
Tax loss and credit carryforwards			149,100,000	176,100,000
Basis differences from acquisitions			28,700,000	20,700,000
Basis differences from short-term assets and liabilities			28,200,000	31,800,000
Other			53,200,000	44,200,000
Deferred tax assets			529,000,000	555,800,000
Valuation allowance			(56,800,000)	(47,800,000)
Net deferred tax assets			472,200,000	508,000,000
Deferred tax liabilities:
Goodwill and intangible assets			673,300,000	635,200,000
Financial instruments			421,800,000	508,700,000
Unremitted foreign earnings			114,500,000	124,700,000
Basis differences from investments			(5,700,000)	12,200,000
Deferred tax liabilities			1,203,900,000	1,280,800,000
Net deferred tax assets (liabilities)			(731,700,000)	(772,800,000)
Net deferred tax assets and (liabilities), classified [Abstract]
Other current assets - Deferred taxes			100,900,000	160,200,000
Long-term deferred tax liabilities			(832,600,000)	(933,000,000)
Convertible debt, repayments of convertible debt						1,382,000,000
Convertible debt, repayments of convertible debt, deferred tax liability			329,000,000
Convertible debt, repayments of convertible debt, deferred tax liability, current			66,000,000
Convertible debt, current taxes payable	52,700,000
Convertible debt, adjustment to additional paid-in capital	34,500,000
Tax loss and credit carryforwards, expiration dates							Dec. 31, 2019	Dec. 31, 2034
Cumulative undistributed earnings of certain foreign subsidiaries indefinitely reinvested			1,500,000,000
Cumulative undistributed earnings of certain foreign subsidiaries not deemed to be indefinitely reinvested			2,100,000,000
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Balance January 1			188,600,000	157,800,000
Current year tax positions			5,100,000	17,100,000
Prior year tax positions			400,000	27,300,000
Reduction of prior year tax positions			(31,400,000)	(7,900,000)
Settlements			(24,600,000)	(200,000)
Lapse of statute of limitations			(200,000)	(6,000,000)
Foreign currency translation				500,000
Foreign currency translation			(100,000)
Balance December 31			137,800,000	188,600,000	157,800,000
Unrecognized tax benefits that would impact effective tax rate			$ 58,700,000	$ 69,700,000