Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
REVENUES:
New vehicle retail sales	$ 1,386,667	$ 1,141,286	$ 3,873,121	$ 3,134,591
Used vehicle retail sales	529,828	462,395	1,536,031	1,333,603
Used vehicle wholesale sales	85,800	78,424	243,667	218,415
Parts and service sales	255,316	224,990	753,776	658,404
Finance, insurance and other, net	82,536	69,477	232,494	192,130
Total revenues	2,340,147	1,976,572	6,639,089	5,537,143
COST OF SALES:
New vehicle retail sales	1,313,372	1,074,736	3,656,825	2,951,379
Used vehicle retail sales	488,346	424,663	1,410,768	1,220,628
Used vehicle wholesale sales	87,334	79,067	242,267	216,031
Parts and service sales	121,633	106,875	358,004	312,106
Total cost of sales	2,010,685	1,685,341	5,667,864	4,700,144
GROSS PROFIT	329,462	291,231	971,225	836,999
SELLING, GENERAL AND ADMINISTRATIVE EXPENSES	(246,863)	(216,082)	(731,455)	(629,521)
DEPRECIATION AND AMORTIZATION EXPENSE	(9,093)	(8,096)	(26,390)	(23,074)
ASSET IMPAIRMENTS	(565)	0	(1,174)	(288)
INCOME FROM OPERATIONS	72,941	67,053	212,206	184,116
OTHER EXPENSE:
Floorplan interest expense	(10,690)	(7,942)	(30,927)	(23,424)
Other interest expense, net	(9,971)	(9,619)	(28,783)	(27,849)
Other expense, net	0	0	(789)	0
INCOME BEFORE INCOME TAXES	52,280	49,492	151,707	132,843
PROVISION FOR INCOME TAXES	(19,515)	(18,157)	(59,436)	(49,766)
NET INCOME	$ 32,765	$ 31,335	$ 92,271	$ 83,077
BASIC EARNINGS PER SHARE	$ 1.34	$ 1.38	$ 3.83	$ 3.64
Weighted average common shares outstanding	23,373	21,521	22,994	21,600
DILUTED EARNINGS PER SHARE	$ 1.19	$ 1.32	$ 3.52	$ 3.50
Weighted average common shares outstanding	26,342	22,458	25,153	22,501
CASH DIVIDENDS PER COMMON SHARE	$ 0.17	$ 0.15	$ 0.48	$ 0.44