Debt (Other Debt) (Details) (Mortgage Loans on Real Estate, USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Mortgage Loan, First Facility
Debt Instrument [Line Items]
Mortgage agreements	6.3	$ 6.5
Weighted average interest rate (as a percent)	2.86%
Mortgage Loan, First Facility | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Variable rate basis	LIBOR
Basis spread on variable rate (as a percentage)	2.70%
Mortgage Loan, Second Facility
Debt Instrument [Line Items]
Mortgage agreements	1.7	$ 1.7
Weighted average interest rate (as a percent)	2.87%