Result of Operations by Segments (Detail) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Segment Reporting Information [Line Items]
Gross revenues	$ 69,197,000	$ 86,965,000	$ 130,996,000	$ 162,444,000	$ 320,000,000
Purchased transportation	55,788,000	71,001,000	105,062,000	132,788,000
Purchased equipment for resale	69,000		283,000
Commissions	8,521,000	11,711,000	16,359,000	21,788,000
Operating expenses	2,924,000	2,661,000	5,961,000	5,036,000
Income from operations	1,895,000	1,592,000	3,331,000	2,832,000	6,400,000
Interest expense	78,000	122,000	172,000	283,000
Income taxes	732,000	565,000	1,244,000	984,000
Net income	1,085,000	905,000	1,915,000	1,565,000	3,600,000
Assets	59,315,000	68,011,000	59,315,000	68,011,000	59,107,000
Transportation services
Segment Reporting Information [Line Items]
Gross revenues	69,033,000	86,438,000	130,529,000	161,381,000
Purchased transportation	55,788,000	71,001,000	105,062,000	132,788,000
Commissions	8,521,000	11,711,000	16,359,000	21,788,000
Operating expenses	2,856,000	2,595,000	5,825,000	4,905,000
Income from operations	1,868,000	1,131,000	3,283,000	1,900,000
Interest expense	78,000	122,000	172,000	283,000
Income taxes	721,000	388,000	1,225,000	624,000
Net income	1,069,000	621,000	1,886,000	993,000
Assets	51,759,000	52,719,000	51,759,000	52,719,000
Agent support services
Segment Reporting Information [Line Items]
Gross revenues	164,000	527,000	467,000	1,063,000
Purchased equipment for resale	69,000		283,000
Operating expenses	68,000	66,000	136,000	131,000
Income from operations	27,000	461,000	48,000	932,000
Income taxes	11,000	177,000	19,000	360,000
Net income	16,000	284,000	29,000	572,000
Assets	$ 7,556,000	$ 15,292,000	$ 7,556,000	$ 15,292,000