Loss of Significant Agent's brokerage division busines (Detail) (USD $)	12 Months Ended
	Dec. 31, 2011
Business Acquisition
Total revenues	$ (253,942,000)
Cost of transportation	(203,042,000)
Commissions	(31,601,000)
Operating expenses	(12,274,000)
Agent's brokerage division business
Business Acquisition
Total revenues	66,028,000
Cost of transportation	56,451,000	[1]
Commissions	8,225,000	[1]
Operating expenses	$ 366,000	[1]

[1] Represents the impact of the loss of the Significant Agent's brokerage division business, as follows: