Consolidated Statements of Changes in Equity Statement (USD $)	Total	Class A [Member]	Class B [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]	Non-controlling Interests [Member]
BALANCE, beginning of period at Dec. 31, 2010	$ (817,240,000)	$ (519,000)	$ (24,000)	$ (358,024,000)	$ (622,185,000)	$ (40,114,000)	$ 203,626,000	$ 0
Net income	119,484,000	0	0	0	119,484,000	0	0	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income	(2,219,000)	0	0	0	0	(2,219,000)	0	0
Dividends paid on A-1 Preferred Stock	0
Proceeds from employee stock purchases	17,433,000	6,000	0	17,427,000	0	0	0	0
Conversion of Class B common stock to Class A common stock	0	2,000	(2,000)	0	0	0	0	0
Compensation cost related to equity awards	7,776,000	0	0	7,776,000	0	0	0	0
Excess tax benefits from share-based compensation	2,246,000	0	0	2,246,000	0	0	0	0
Treasury stock acquisitions	(1,326,000)	0	0	0	0	0	(1,326,000)	0
BALANCE, end of period at Dec. 31, 2011	(960,634,000)	(527,000)	(22,000)	(385,473,000)	(741,669,000)	(37,895,000)	204,952,000	0
Net income	52,433,000	0	0	0	52,433,000	0	0	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income	9,376,000	0	0	0	0	9,376,000	0	0
Dividends paid on A-1 Preferred Stock	(4,375,000)	0	0	0	(4,375,000)	0	0	0
Proceeds from employee stock purchases	19,320,000	9,000	0	19,311,000	0	0	0	0
Conversion of Class B common stock to Class A common stock	0	5,000	(5,000)	0	0	0	0	0
Compensation cost related to equity awards	12,151,000	0	0	12,151,000	0	0	0	0
Compensation costs related to equity awards included in income from equity investment	2,816,000	0	0	2,816,000	0	0	0	0
Excess tax benefits from share-based compensation	4,795,000	0	0	4,795,000	0	0	0	0
Stock issuance proceeds, net of stock issuance costs	234,340,000	38,000	0	234,302,000	0	0	0	0
TEU Purchase Contracts issuance proceeds, net of issuance costs	191,428,000	0	0	191,428,000	0	0	0	0
RailAmerica acquisition consideration for share-based awards	15,400,000	0	0	15,400,000	0	0	0	0
Treasury stock acquisitions	(4,314,000)	0	0	0	0	0	(4,314,000)	0
Settlement of deferred stock awards	933,000	0	0	933,000	0	0	0	0
Noncontrolling interest - increase from RailAmerica acquisition	5,525,000	0	0	0	0	0	0	5,525,000
BALANCE, end of period at Dec. 31, 2012	$ (1,500,462,000)	$ (579,000)	$ 17,000	$ (866,609,000)	$ (789,727,000)	$ (47,271,000)	$ 209,266,000	$ (5,525,000)