Business Combinations (Tables)

12 Months Ended

Dec. 31, 2011

Business Combinations [Abstract]

Summary of the aggregate consideration paid and the aggregate amounts of the assets acquired and liabilities assumed

	December 31,
	2011			2010
Accounts receivable	$	953		$	—
Inventory		61,247			11,520
Other current assets		—			45
Property and equipment		40,190			4,932
Goodwill		107,498			8,274
Franchise value		29,491
Other assets		628
Current liabilities		(6,190	)		(279	)
Total consideration		233,817			24,492
Seller financed/assumed debt		(1,711	)		(2,260	)
Cash used in dealership acquisitions	$	232,106		$	22,232

Summary of unaudited consolidated pro forma results of operations

	Year Ended December 31,
	2011		2010
Revenues	$	11,583,093	$	10,714,528
Income from continuing operations		178,401		128,855
Net income		179,380		113,892
Income from continuing operations per diluted common share	$	1.94	$	1.39
Net income per diluted common share	$	1.97	$	1.24