Equity Investment RailAmerica Condensed Statement of Operations(Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended			3 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 28, 2012 RailAmerica [Member]
OPERATING REVENUES	$ 227,316	$ 222,745	$ 217,419	$ 207,436	$ 210,386	$ 217,210	$ 209,589	$ 191,911	$ 874,916	$ 829,096	$ 630,195	$ 151,065
OPERATING EXPENSES									684,594	637,317	499,785	124,928
INCOME FROM OPERATIONS	33,660	52,875	62,473	41,314	45,388	56,023	51,165	39,203	190,322	191,779	130,410	26,137
INTEREST EXPENSE									62,845	38,617	23,147	(90)
OTHER INCOME												9
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES												26,056
PROVISION FOR INCOME TAXES												10,250
INCOME FROM CONTINUING OPERATIONS									52,551	119,493	78,669	15,806
NET INCOME ATTRIBUTABLE TO NONCONTROLLING INTEREST												0
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS	$ 9,021	$ (19,567)	$ 36,363	$ 22,241	$ 33,275	$ 32,942	$ 31,145	$ 22,122				$ 15,806