Selected Quarterly Data Summary of Selected Quarterly Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 2,469,855	$ 2,465,800	$ 2,458,411	$ 2,342,843	$ 2,150,406	$ 2,207,343	$ 2,304,806	$ 1,921,476	$ 9,736,909	$ 8,584,031	$ 7,192,633
Gross margin	947,645	956,876	965,009	930,093	830,006	855,444	905,816	760,437	3,799,623	3,351,703	2,833,529
Operating income	167,954	199,099	244,573	235,692	161,880	183,401	232,445	185,672	847,318	763,398	704,627
Income from continuing operations	122,870	122,381	150,914	140,809	96,298	109,844	137,810	112,171	536,974	456,123	423,223
Net (loss) income from discontinued operations	(2,215)	0	0	(4,531)	(9,967)	12,844	4,975		(6,746)	7,852	0
Net loss attributable to noncontrolling interest	(3,516)								(3,516)	0	0
Net income attributable to LKQ stockholders	$ 124,171	$ 122,381	$ 150,914	$ 136,278	$ 86,331	$ 122,688	$ 142,785	$ 112,171	$ 533,744	$ 463,975	$ 423,223
Basic earnings per share from continuing operations	$ 0.40	$ 0.40	$ 0.49	$ 0.46	$ 0.31	$ 0.36	$ 0.45	$ 0.37	$ 1.74	$ 1.49	$ 1.39
Diluted earnings per share from continuing operations	$ 0.39	$ 0.39	$ 0.49	$ 0.45	$ 0.31	$ 0.35	$ 0.45	$ 0.36	$ 1.73	$ 1.47	$ 1.38
Loss on sale of business	$ (2,000)			$ (4,000)					$ 6,495	$ 0	$ 0