Derivatives and Hedging Activity (Details) In Millions, unless otherwise specified	9 Months Ended		9 Months Ended
	Sep. 30, 2013 Interest rate swaps Derivatives designated as cash flow hedging instruments USD ($) instrument	Sep. 30, 2013 Interest rate swaps Derivatives not designated as hedging instruments USD ($) instrument	Sep. 30, 2013 Interest rate swaps Derivatives not designated as hedging instruments Minimum	Sep. 30, 2013 Interest rate swaps Derivatives not designated as hedging instruments Maximum	Sep. 30, 2013 Foreign exchange contracts Derivatives not designated as hedging instruments GBP GBP (£) instrument	Sep. 30, 2013 Foreign exchange contracts Derivatives not designated as hedging instruments EUR EUR (€) instrument	Sep. 30, 2013 Credit spread instrument Derivatives not designated as hedging instruments USD ($) instrument	Sep. 30, 2013 Forward contracts Derivatives not designated as hedging instruments instrument
Derivatives
Number of derivative instruments held	8	34					4	14
Notional amount of derivative instruments	$ 183.4	$ 239.1					$ 50.0
Fixed monthly coupons at fixed rate, low end of range (as a percent)	0.557%
Fixed monthly coupons at fixed rate, high end of range (as a percent)	2.228%
Floating rate	LIBOR
Amount expected to be reclassified from other comprehensive income to interest expense over the next twelve months	1.4
Hedging period for covering exposure to the variability in future cash flows	93 months
Number of derivative instruments held to purchase foreign exchange					1
Number of derivative instruments held					45	20
Maturity period			3 years	10 years
Notional amount of derivative instruments to purchase foreign exchange					64.1
Notional amount of derivative instruments to sell foreign exchange					£ 198.3	€ 132.4