Basis of financial statement presentation - Property, Plant and Equipment (Details)	12 Months Ended
	Dec. 31, 2012
Buildings
Property, Plant and Equipment [Line Items]
Residual value, percent	10.00%
Buildings | Maximum
Property, Plant and Equipment [Line Items]
Useful lives	60 years
Tourist trains | Maximum
Property, Plant and Equipment [Line Items]
Useful lives	75 years
River cruise ship and canal boats
Property, Plant and Equipment [Line Items]
Useful lives	25 years
Furniture fixtures and equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful lives	5 years
Furniture fixtures and equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful lives	25 years