Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	6 Months Ended		12 Months Ended
	Dec. 31, 2021	Jun. 30, 2021	Dec. 31, 2023	Dec. 31, 2022
Revenue	$ 1,554		$ 3,410	$ 3,132
Cost of services, exclusive of depreciation and amortization	1,001		2,188	2,080
Depreciation and amortization	21		82	56
Gross Profit	532		1,140	996
Operating Expenses
Selling, general and administrative	304		754	671
Depreciation and intangible amortization	163		339	339
Goodwill impairment			148
Total Operating expenses	467		1,241	1,010
Operating Income (Loss)	65		(101)	(14)
Other (Income) Expense
(Gain) Loss from change in fair value of financial instruments	65		10	(38)
(Gain) loss from change in fair value of tax receivable agreement	(37)		118	(41)
Interest expense	57		131	122
Other (income) expense, net	3		6	(16)
Total Other (income) expense, net	88		265	27
Income (Loss) Before Taxes	(23)		(366)	(41)
Income tax expense (benefit)	25		(4)	31
Net Income (Loss)	(48)		(362)	(72)
Net income (loss) attributable to noncontrolling interests	(13)		(17)	(10)
Net Income (Loss) Attributable to Alight, Inc.	$ (35)		$ (345)	$ (62)
Earnings Per Share
Basic (net loss) earnings per share	$ (0.08)		$ (0.7)	$ (0.14)
Diluted (net loss) earnings per share	$ (0.08)		$ (0.7)	$ (0.14)
Other comprehensive income (loss), net of tax:
Change in fair value of derivatives	$ 9		$ (42)	$ 114
Foreign currency translation adjustments			9	(14)
Total Other comprehensive income (loss), net of tax:	9		(33)	100
Comprehensive Income (Loss) Before Noncontrolling Interests	(39)		(395)	28
Comprehensive income (loss) attributable to noncontrolling interests	(12)		(26)	3
Comprehensive Income (Loss) Attributable to Alight, Inc.	(27)		(369)	25
Alight Holdings
Revenue	1,554	$ 1,361
Cost of services, exclusive of depreciation and amortization		888
Depreciation and amortization		38
Gross Profit		435
Operating Expenses
Selling, general and administrative	304	222	754	671
Depreciation and intangible amortization	163	111	339	339
Goodwill impairment	0	0	148	0
Total Operating expenses		333
Operating Income (Loss)	65	102	(101)	(14)
Other (Income) Expense
(Gain) Loss from change in fair value of financial instruments	65	0	10	(38)
(Gain) loss from change in fair value of tax receivable agreement	(37)	0	118	(41)
Interest expense	57	123	131	122
Other (income) expense, net	3	9	6	(16)
Total Other (income) expense, net		132
Income (Loss) Before Taxes	$ (23)	(30)	$ (366)	$ (41)
Income tax expense (benefit)		(5)
Net Income (Loss)		(25)
Net Income (Loss) Attributable to Alight, Inc.		(25)
Other comprehensive income (loss), net of tax:
Change in fair value of derivatives		23
Foreign currency translation adjustments		8
Total Other comprehensive income (loss), net of tax:		31
Comprehensive Income (Loss) Before Noncontrolling Interests		6
Comprehensive Income (Loss) Attributable to Alight, Inc.		$ 6