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Equity Based Compensation (Narrative) (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Allocated Share-based Compensation Expense									$ 24.4	$ 20.3	$ 28.5
Options, Exercises in Period, Total Intrinsic Value									17.0	11.3	11.2
Options, Grants in Period, Weighted Average Grant Date Fair Value									$ 26.76	$ 18.58	$ 19.65
Fair Value Assumptions, Expected Dividend Rate									1.53%	1.63%	1.27%
Fair Value Assumptions, Risk Free Interest Rate									2.27%	1.36%	1.38%
Fair Value Assumptions, Expected Term									7 years	6 years 9 months	6 years 8 months 15 days
Fair Value Assumptions, Expected Volatility Rate									35.70%	35.40%	37.20%
Performance Contingent Units Outstanding									232,208	252,942	243,578
Performance Contingent Units Maximum Shares of Common Stock Per PCU									2
Performance Contingent Units Measurement Period									3 years
Performance Contingent Unit Share Payout									0.529	1.513
Performance Contingent Units Shares of Common Stock Issued									103,358	339,483
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized	$ 25.4								$ 25.4
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition									1 year 9 months
Equity Based Compensation [Line Items]
Earnings Per Share, Basic (in dollars per share)	$ 2.78us-gaap_EarningsPerShareBasic	$ 2.30us-gaap_EarningsPerShareBasic	$ 2.87us-gaap_EarningsPerShareBasic	$ 1.94us-gaap_EarningsPerShareBasic	$ 2.05us-gaap_EarningsPerShareBasic	$ 1.95us-gaap_EarningsPerShareBasic	$ (0.69)us-gaap_EarningsPerShareBasic	$ 2.51us-gaap_EarningsPerShareBasic	$ 9.88us-gaap_EarningsPerShareBasic	$ 5.82us-gaap_EarningsPerShareBasic	$ 8.57us-gaap_EarningsPerShareBasic
Options, Grants in Period, Weighted Average Exercise Price									$ 78.48	$ 58.77	$ 56.65
Stock Options [Member]
Equity Based Compensation [Line Items]
Expiration Period									10 years
Options, Grants in Period, Net of Forfeitures									232,782,000
Flexible Stock Plan [Member]
Equity Based Compensation [Line Items]
Number Of Shares Available For Grant	13,360,077								13,360,077
Flexible Stock Plan For Directors [Member]
Equity Based Compensation [Line Items]
Number Of Shares Available For Grant	212,500								212,500
Restricted Stock Units (RSUs) [Member]
Equity Based Compensation [Line Items]
Options, Grants in Period, Net of Forfeitures									234,740	261,322	257,679
Minimum [Member]
Equity Based Compensation [Line Items]
Vesting Period									1 year
Maximum [Member]
Equity Based Compensation [Line Items]
Vesting Period									5 years