Long-term Obligations - Fan Pier Leases (Details) - Fan Pier Leases ft² in Millions	12 Months Ended
	Dec. 31, 2011 ft² lease building
Property, Plant and Equipment [Line Items]
Number of leases | lease	2
Area of real estate property (in square feet) | ft²	1.1
Number of buildings under lease agreement | building	2
Optional term of lease agreement (in years)	10 years