Unaudited Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interest
July 1, 2018 at Dec. 31, 2016		307,545
July 1, 2018 at Dec. 31, 2016	$ 3,442,949	$ 3,075	$ 1,116,690	$ 2,590,359	$ (267,175)
Net income	409,573
Net income attributable to LKQ stockholders	409,573			409,573
Other comprehensive income	169,563				169,563
Vesting of restricted stock units, net of shares withheld for employee tax		736
Vesting of restricted stock units, net of shares withheld for employee tax	(3,895)	$ 7	(3,902)
Stock-based compensation expense	17,582		17,582
Exercise of stock options		772
Exercise of stock options	6,465	$ 8	6,457
Shares withheld for net share settlement of stock option awards		(35)
Shares withheld for net share settlement of stock option awards	(1,200)		(1,200)
September 30, 2018 at Sep. 30, 2017		309,018
September 30, 2018 at Sep. 30, 2017	4,041,037	$ 3,090	1,135,627	2,999,932	(97,612)
July 1, 2018 at Jun. 30, 2017		308,621
July 1, 2018 at Jun. 30, 2017	3,856,685	$ 3,086	1,130,318	2,877,551	(154,270)
Net income	122,381
Net income attributable to LKQ stockholders	122,381			122,381
Other comprehensive income	56,658				56,658
Vesting of restricted stock units, net of shares withheld for employee tax		259
Vesting of restricted stock units, net of shares withheld for employee tax	(1,140)	$ 2	(1,142)
Stock-based compensation expense	5,139		5,139
Exercise of stock options		139
Exercise of stock options	1,314	$ 2	1,312
Shares withheld for net share settlement of stock option awards		(1)
September 30, 2018 at Sep. 30, 2017		309,018
September 30, 2018 at Sep. 30, 2017	4,041,037	$ 3,090	1,135,627	2,999,932	(97,612)
Noncontrolling interest	8,484					$ 8,484
July 1, 2018 at Dec. 31, 2017		309,127
July 1, 2018 at Dec. 31, 2017	4,206,653	$ 3,091	1,141,451	3,124,103	(70,476)
Net income	445,109
Less: net income attributable to noncontrolling interest	1,040					1,040
Net income attributable to LKQ stockholders	444,069			444,069
Other comprehensive income	(69,660)				(69,660)
Stock issued in acquisitions		8,056
Stock issued in acquisitions	251,334	$ 81	251,253
Vesting of restricted stock units, net of shares withheld for employee tax		600
Vesting of restricted stock units, net of shares withheld for employee tax	(3,711)	$ 6	(3,717)
Stock-based compensation expense	17,544		17,544
Exercise of stock options		441
Exercise of stock options	3,772	$ 4	3,768
Shares withheld for net share settlement of stock option awards		(27)
Shares withheld for net share settlement of stock option awards	(1,057)		(1,057)
Adoption of ASU 2018-02 (see Note 4)	5,345			(5,345)	5,345
Capital contributions from, net of dividends to, noncontrolling interest shareholder	3,182					3,182
Acquired noncontrolling interest	44,250					44,250
September 30, 2018 at Sep. 30, 2018		318,197
September 30, 2018 at Sep. 30, 2018	4,897,416	$ 3,182	1,409,242	3,562,827	(134,791)	56,956
Noncontrolling interest						57,503
July 1, 2018 at Jun. 30, 2018		317,821
July 1, 2018 at Jun. 30, 2018	4,776,975	$ 3,178	1,403,630	3,428,725	(116,061)
Net income	134,480
Less: net income attributable to noncontrolling interest	378					378
Net income attributable to LKQ stockholders	134,102			134,102
Other comprehensive income	(18,730)				(18,730)
Vesting of restricted stock units, net of shares withheld for employee tax		256
Vesting of restricted stock units, net of shares withheld for employee tax	(934)	$ 3	(937)
Stock-based compensation expense	5,700		5,700
Exercise of stock options		120
Exercise of stock options	850	$ 1	849
Capital contributions from, net of dividends to, noncontrolling interest shareholder	(925)					(925)
September 30, 2018 at Sep. 30, 2018		318,197
September 30, 2018 at Sep. 30, 2018	4,897,416	$ 3,182	$ 1,409,242	$ 3,562,827	$ (134,791)	$ 56,956
Noncontrolling interest	$ 56,956