Condensed Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jul. 04, 2025	Jun. 28, 2024	Jul. 04, 2025	Jun. 28, 2024
Income Statement [Abstract]
Revenues	$ 1,952	$ 1,847	$ 3,970	$ 3,665
Cost of revenues	(1,662)	(1,577)	(3,380)	(3,147)
Gross profit	290	270	590	518
Equity in earnings of unconsolidated affiliates	51	40	93	70
Selling, general and administrative expenses	(146)	(129)	(286)	(250)
Other	(1)	(1)	(1)	8
Operating income (loss)	194	180	396	346
Interest expense	(41)	(32)	(82)	(63)
Other non-operating income (expense)	(8)	(2)	(5)	(8)
Income from continuing operations before income taxes	145	146	309	275
Provision for income taxes	(39)	(40)	(82)	(75)
Net income from continuing operations	106	106	227	200
Net income (loss) from discontinued operations, net of tax	(48)	1	(54)	1
Net income	58	107	173	201
Less: Net income attributable to noncontrolling interests included in continuing operations	1	0	2	1
Less: Net income (loss) attributable to noncontrolling interests included in discontinued operations	(16)	1	(18)	1
Net income attributable to KBR	$ 73	$ 106	$ 189	$ 199
Net income attributable to KBR per share
Basic earnings per share from continuing operations (in usd per share)	$ 0.81	$ 0.79	$ 1.72	$ 1.48
Basic loss per share from discontinued operations (in usd per share)	(0.25)	0	(0.27)	0
Basic earnings per share attributable to KBR (in usd per share)	0.56	0.79	1.45	1.48
Diluted earnings per share from continuing operations (in usd per share)	0.81	0.79	1.71	1.47
Diluted loss per share from discontinued operations (in usd per share)	(0.25)	0	(0.27)	0
Diluted earnings per share attributable to KBR (in usd per share)	$ 0.56	$ 0.79	$ 1.44	$ 1.47
Basic weighted average common shares outstanding (in shares)	129	134	130	134
Diluted weighted average common shares outstanding (in shares)	129	134	131	135
Cash dividends declared per share (in usd per share)	$ 0.165	$ 0.150	$ 0.330	$ 0.300