Real estate impairment (Details) (USD $)	12 Months Ended			12 Months Ended				0 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012	Dec. 31, 2012 Porto Cupecoy	Dec. 31, 2011 Porto Cupecoy	Dec. 31, 2010 Porto Cupecoy	Dec. 31, 2011 Fair value Porto Cupecoy	Jan. 31, 2013 Subsequent Event Porto Cupecoy
Real estate impairment
Cash proceeds from divestiture of businesses								$ 19,000,000
Total impairment charge related to real estate and property development segment	38,545,000	24,616,000
Non-cash impairment charge of real estate				(3,166,000)	(36,868,000)	(24,616,000)
Assets of discontinued operations held for sale	135,390,000		22,078,000				0
Non-cash property, plant and equipment impairment charge					$ 1,677,000