Derivatives (Forward Contract Collateral) (Details) In Millions, unless otherwise specified	Sep. 30, 2014 USD ($)	Sep. 30, 2014 JPY (¥)	Dec. 31, 2013 USD ($)	Dec. 31, 2013 JPY (¥)	Mar. 01, 2007 USD ($)	Mar. 01, 2007 JPY (¥)	Sep. 01, 2006 USD ($)	Sep. 01, 2006 JPY (¥)	Sep. 30, 2014 Forward Contracts USD ($) Rating	Sep. 30, 2014 Forward Contracts SEK	Dec. 31, 2013 Forward Contracts USD ($)	Sep. 30, 2014 Interest Rate Cap Rating	Sep. 30, 2014 Standard & Poor's, A Rating Forward Contracts Barclays USD ($)	Dec. 31, 2013 Standard & Poor's, A Rating Forward Contracts Barclays USD ($)	Sep. 30, 2014 Standard & Poor's, A Rating Forward Contracts Deutsche Bank USD ($)	Dec. 31, 2013 Standard & Poor's, A Rating Forward Contracts Deutsche Bank USD ($)	Sep. 30, 2014 Standard & Poor's, A Rating Forward Contracts Goldman Sachs USD ($)	Dec. 31, 2013 Standard & Poor's, A Rating Forward Contracts Goldman Sachs USD ($)	Sep. 30, 2014 Standard & Poor's, A plus Forward Contracts JP Morgan USD ($)	Dec. 31, 2013 Standard & Poor's, A plus Forward Contracts JP Morgan USD ($)	Sep. 30, 2014 Standard & Poor's, AA- Rating Forward Contracts HSBC USD ($)	Dec. 31, 2013 Standard & Poor's, AA- Rating Forward Contracts HSBC USD ($)	Sep. 30, 2014 Standard & Poor's, AA- Rating Forward Contracts Royal Bank of Canada USD ($)	Dec. 31, 2013 Standard & Poor's, AA- Rating Forward Contracts Royal Bank of Canada USD ($)
Derivative [Line Items]
Notional amount	$ 1,400.0	¥ 156,800.0	$ 1,900.0	¥ 203,600.0	$ 500.0	¥ 56,000.0	$ 1,700.0	¥ 200,000.0	$ 9.4	68.0	$ 20.4		$ 1.3	$ 5.8	$ 2.2	$ 7.7	$ 3.6	$ 2.1	$ 1.2	$ 1.3	$ 1.1	$ 3.3	$ 0	$ 0.2
Carrying Value									$ 0.2		$ (0.1)		$ 0	$ 0	$ 0.1	$ 0	$ 0.1	$ 0	$ 0	$ 0	$ 0	$ (0.1)	$ 0	$ 0
S and P Credit Ratings									21	21		21