Property, plant and equipment - Major classes of property, plant and equipment (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Property, plant and equipment
Property, plant and equipment, gross	$ 1,400,154	$ 1,452,139
Less: Accumulated depreciation	(323,735)	(330,390)
Total property, plant and equipment, net of accumulated depreciation	1,076,419	1,121,749
Land and buildings
Property, plant and equipment
Property, plant and equipment, gross	971,628	1,013,015
Machinery and equipment
Property, plant and equipment
Property, plant and equipment, gross	205,689	210,992
Fixtures, fittings and office equipment
Property, plant and equipment
Property, plant and equipment, gross	203,711	209,050
River cruise ship and canal boats
Property, plant and equipment
Property, plant and equipment, gross	$ 19,126	$ 19,082