Earnings per Share - Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Basic earnings per common share
Net income attributable to XPO	$ 422	$ 340	$ 69
Convertible preferred dividends	(3)	(3)	(3)
Non-cash allocation of undistributed earnings	(29)	(25)	(3)
Net income allocable to common shares, basic	$ 390	$ 312	$ 63
Basic weighted-average common shares outstanding (in shares)	123	115	110
Basic earnings per share (in usd per share)	$ 3.17	$ 2.72	$ 0.57
Diluted earnings per common share
Interest from Convertible Senior Notes	$ 0	$ 1	$ 2
Net income allocable to common shares, diluted	$ 390	$ 313	$ 65
Dilutive effect of Convertible Senior Notes (in shares)	0	2	3
Dilutive effect of non-participating stock-based awards and equity forward (in shares)	12	11	10
Diluted weighted-average common shares (in shares)	135	128	123
Diluted earnings per share (in usd per share)	$ 2.88	$ 2.45	$ 0.53
Potential common shares excluded (in shares)	10	10	12