Changes in Operations United States (Details) (USD $)	3 Months Ended	12 Months Ended					12 Months Ended		12 Months Ended	3 Months Ended	12 Months Ended			0 Months Ended
	Sep. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2011 AZER [Member]	Sep. 01, 2011 AZER [Member] employees track_miles trackage_rights_miles rail_lines locomotives	Dec. 31, 2012 RailAmerica [Member]	Oct. 02, 2012 RailAmerica [Member] track_miles provinces states employees railroads	Dec. 31, 2012 Forward Contracts [Member] The Carlyle Group [Member] RailAmerica [Member]	Dec. 31, 2012 RailAmerica [Member]	Dec. 31, 2012 RailAmerica [Member]	Jul. 02, 2012 CCH [Member] track_miles	Nov. 30, 2011 HAL [Member] track_miles	Oct. 02, 2012 Common stock and TEUs [Member] RailAmerica [Member]	Oct. 02, 2012 Series A-1 Preferred Stock [Member] The Carlyle Group [Member] RailAmerica [Member]
Business Acquisition [Line Items]
Percentage of RailAmerica's outstanding shares acquired								100.00%
Acquisition Purchase Price Per Share								$ 27.50
Acquisition Equity Interests Issued and Issuable								$ 1,373,184,000
Acquisition refinancing of debt								1,200,000,000
Amount of debt used to fund transaction and financing costs								1,900,000,000
Proceeds from Issuance of Common Stock		234,340,000												475,500,000
Proceeds from issuance of stock															350,000,000
Contingent forward sale contract mark-to-market expense	(50,100,000)	50,106,000	0	0					50,100,000
Acquisition costs		18,592,000	0	0	600,000		18,600,000
Integration costs		11,452,000	0	0			11,500,000
Income from equity investment in RailAmerica, net		15,557,000	0	0							15,600,000
Acquisition/integration costs										3,500,000
Number of employees acquired						43		2,000
Number of railroads								45
Track miles acquired						200		7,100
Number of States in which Entity Operates								28
Number of Provinces in which Entity Operates								3
Track miles leased												26	56
Working capital adjustment					800,000	(600,000)
Number of locomotives acquired						10
Number of rail lines acquired						2
Trackage rights miles acquired						52
Total Consideration [Abstract]
RailAmerica outstanding common stock								49,934,000
Cash purchase price per share								$ 27.50
Equity purchase price								1,373,184,000
Payment of RailAmerica's outstanding term loan and revolving credit facility								659,198,000
Cash consideration								2,032,382,000
Impact of pre-acquisition share-based awards								9,400,000
Total consideration						$ 89,500,000		$ 2,041,782,000