Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Net income	$ 33,275	$ 32,942	$ 31,145	$ 22,122	$ 19,870	$ 24,795	$ 20,635	$ 15,960	$ 119,484	$ 81,260	$ 61,473
Currency translation adjustments									(3,511)	21,877	29,378
Net unrealized gain/(loss) on qualifying cash flow hedges, net of tax									1,334	(1,590)	3,991
Changes in pension and other postretirement benefits, net of tax									(42)	344	147
Comprehensive Income									117,265	101,891	94,989
Comprehensive income attributable to the noncontrolling interest									0	0	146
Comprehensive income attributable to Genesee & Wyoming Inc.									117,265	101,891	94,843
Retained Earnings [Member]
Net income									119,484	81,260	61,327
Currency translation adjustments									0	0	0
Net unrealized gain/(loss) on qualifying cash flow hedges, net of tax									0	0	0
Changes in pension and other postretirement benefits, net of tax											$ 0