Fair Value Disclosures (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Assets, Fair Value Disclosure	$ 126.5	$ 83.8
Debt instrument, principal outstanding	125.0
Convertible debentures, fair value	223.7
Estimate Of Fair Value, Fair Value Disclosure [Member]
Foreign currency forward contracts (asset position)	11.1	28.0
Foreign currency forward contracts (liability position)	44.2	9.6
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Foreign currency forward contracts (asset position)	0	0
Foreign currency forward contracts (liability position)	0	0
Significant Other Observable Inputs (Level 2) [Member]
Foreign currency forward contracts (asset position)	11.1	28.0
Foreign currency forward contracts (liability position)	44.2	9.6
Significant Unobservable Inputs (Level 3) [Member]
Foreign currency forward contracts (asset position)	0	0
Foreign currency forward contracts (liability position)	0	0
Interest-bearing Deposits [Member]
Assets, Fair Value Disclosure	113.0	64.3
Interest-bearing Deposits [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Assets, Fair Value Disclosure	0	0
Interest-bearing Deposits [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets, Fair Value Disclosure	113.0	64.3
Interest-bearing Deposits [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets, Fair Value Disclosure	0	0
Equity Funds [Member]
Assets, Fair Value Disclosure	10.7	13.3
Equity Funds [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Assets, Fair Value Disclosure	10.7	13.3
Equity Funds [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets, Fair Value Disclosure	0	0
Equity Funds [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets, Fair Value Disclosure	0	0
Common Stock [Member]
Assets, Fair Value Disclosure	2.0	4.9
Common Stock [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Assets, Fair Value Disclosure	2.0	4.9
Common Stock [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets, Fair Value Disclosure	0	0
Common Stock [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets, Fair Value Disclosure	0	0
Money Market Funds [Member]
Assets, Fair Value Disclosure	0.8	1.3
Money Market Funds [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Assets, Fair Value Disclosure	0.8	1.3
Money Market Funds [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets, Fair Value Disclosure	0	0
Money Market Funds [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets, Fair Value Disclosure	0	0
Investment Securities Class [Domain]
Assets, Fair Value Disclosure	13.5	19.5
Investment Securities Class [Domain] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Assets, Fair Value Disclosure	13.5	19.5
Investment Securities Class [Domain] | Significant Other Observable Inputs (Level 2) [Member]
Assets, Fair Value Disclosure	0	0
Investment Securities Class [Domain] | Significant Unobservable Inputs (Level 3) [Member]
Assets, Fair Value Disclosure	$ 0	$ 0