Derivatives and Hedging Activity (Details) In Millions, unless otherwise specified	6 Months Ended		6 Months Ended			6 Months Ended
	Jun. 30, 2014 Interest rate swaps Derivatives designated as hedging instruments USD ($) instrument	Jun. 30, 2014 Interest rate swaps Derivatives not designated as hedging instruments Long USD ($) instrument	Jun. 30, 2014 Interest rate swaps Derivatives not designated as hedging instruments Long Minimum	Jun. 30, 2014 Interest rate swaps Derivatives not designated as hedging instruments Long Maximum	Jun. 30, 2014 Interest rate swaps Derivatives not designated as hedging instruments Short USD ($) instrument	Jun. 30, 2014 Interest rate swaps Derivatives not designated as hedging instruments Short Minimum	Jun. 30, 2014 Interest rate swaps Derivatives not designated as hedging instruments Short Maximum	Jun. 30, 2014 Foreign exchange contracts Derivatives not designated as hedging instruments GBP instrument	Jun. 30, 2014 Foreign exchange contracts Derivatives not designated as hedging instruments GBP Short GBP (£)	Jun. 30, 2014 Foreign exchange contracts Derivatives not designated as hedging instruments EUR instrument	Jun. 30, 2014 Foreign exchange contracts Derivatives not designated as hedging instruments EUR Long EUR (€) instrument	Jun. 30, 2014 Foreign exchange contracts Derivatives not designated as hedging instruments EUR Short EUR (€)	Jun. 30, 2014 Foreign exchange contracts Derivatives not designated as hedging instruments SEK Short USD ($) instrument	Jun. 30, 2014 Foreign exchange contracts Derivatives not designated as hedging instruments NOK Short USD ($) instrument	Jun. 30, 2014 Foreign exchange contracts Derivatives not designated as hedging instruments DKK Short USD ($) instrument	Jun. 30, 2014 Credit spread instrument Derivatives not designated as hedging instruments USD ($) instrument
Derivatives
Number of derivative instruments held	7	34			4						1		2	1	1	8
Notional amount of derivative instruments	$ 162.9	$ 203.1			$ 59.9				£ 226.2		€ 60.3	€ 147.9	$ 23.0	$ 1.3	$ 3.2	$ 50.0
Fixed monthly coupons at fixed rate, low end of range (as a percent)	0.56%
Fixed monthly coupons at fixed rate, high end of range (as a percent)	2.23%
Floating rate	LIBOR
Amount expected to be reclassified from other comprehensive income to interest expense over the next twelve months	$ 1.0
Hedging period for covering exposure to the variability in future cash flows	83 months
Number of derivative instruments held								66		29
Maturity period			2 years	10 years		0 years	3 years