Purchase Price Allocations for Acquisitions (Detail) In Thousands, unless otherwise specified	Sep. 30, 2012 USD ($)	Dec. 31, 2011 USD ($)	Sep. 30, 2012 All 2012 Acquisitions USD ($)	Dec. 31, 2011 Euro Car Parts Holdings Limited USD ($)	Dec. 31, 2011 Euro Car Parts Holdings Limited GBP (£)	Dec. 31, 2011 All 2011 Acquisitions Excluding ECP USD ($)	Dec. 31, 2011 All 2011 Acquisitions USD ($)
Business Acquisition
Receivables			$ 5,246	$ 54,225		$ 23,538	$ 77,763
Receivable reserves			(542)	(3,832)		(1,121)	(4,953)
Inventory			35,399	93,835		59,846	153,681
Prepaid expenses and other current assets			36	3,189		2,820	6,009
Property and equipment			8,632	41,830		10,614	52,444
Goodwill	1,597,936	1,476,063	109,878	332,891		105,177	438,068
Other intangibles			479	43,723		7,683	51,406
Other assets			161	13		9,420	9,433
Deferred income taxes			122	(13,218)		7,235	(5,983)
Current liabilities assumed			(16,341)	(135,390)		(17,257)	(152,647)
Debt assumed				(13,564)			(13,564)
Other noncurrent liabilities assumed						(619)	(619)
Contingent consideration liabilities			(5,540)	(77,539)	(50,200)	(3,700)	(81,239)
Other purchase price obligations			(66)	(4,136)	(2,700)	(4,510)	(8,646)
Notes issued			(8,206)	(28,302)	(18,400)	(5,917)	(34,219)
Cash used in acquisitions, net of cash acquired			$ 129,258	$ 293,725	£ 190,300	$ 193,209	$ 486,934