Consolidated Statement of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Comprehensive income (loss):
Net income (loss)	$ 270	$ 569
Cash flow hedging activities:
Net unrealized gain (loss) from derivative instruments, net of taxes of $0 in 2018 and ($1) in 2017	1	3
Pension and other postretirement benefits:
Amortization of prior service cost (credit) included in net periodic benefit cost (credit)	0	(1)
Amortization of actuarial (gain) loss included in net periodic benefit cost (credit), net of taxes of ($1) in 2018 and ($3) in 2017	5	4
Other comprehensive income (loss)	6	6
Comprehensive income (loss)	276	575
Less: Comprehensive income (loss) attributable to noncontrolling interests	119	197
Comprehensive income (loss) attributable to The Williams Companies, Inc.	$ 157	$ 378