Consolidated Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues:
New and used commercial vehicle sales	$ 2,239,847	$ 2,149,335	$ 1,801,964
Parts and service sales	988,317	817,280	675,277
Lease and rental	129,638	100,247	83,426
Finance and insurance	15,320	13,638	10,867
Other	11,583	10,067	9,077
Total revenue	3,384,705	3,090,567	2,580,611
Cost of products sold:
New and used commercial vehicle sales	2,083,439	2,005,776	1,679,170
Parts and service sales	620,030	499,850	408,544
Lease and rental	109,222	84,174	69,620
Total cost of products sold	2,812,691	2,589,800	2,157,334
Gross profit	572,014	500,767	423,277
Selling, general and administrative	450,340	361,727	306,273
Depreciation and amortization	29,925	25,016	20,084
Gain on sale of assets	5	176	418
Operating income	91,754	114,200	97,338
Interest income (expense):
Interest income	41	21	20
Interest expense	(10,734)	(13,038)	(7,181)
Total interest expense, net	10,693	13,017	7,161
Income before taxes	81,061	101,183	90,177
Provision for income taxes	31,844	38,728	34,964
Net income	$ 49,217	$ 62,455	$ 55,213
Earnings per common share - Basic:
Net income (in Dollars per share)	$ 1.25	$ 1.62	$ 1.46
Earnings per common share - Diluted:
Net income (in Dollars per share)	$ 1.22	$ 1.57	$ 1.42