Postemployment Benefit Plans (Funded) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Change in projected benefit obligation
Projected benefit obligation, beginning of period	$ 2,049	$ 2,280
Actuarial (gains) losses, net	85	(154)
Service cost	13	32
Interest cost	87	86
Plan amendments		(33)
Currency exchange rate changes	(77)	(48)
Participant contributions	1	4
Benefits paid	(140)	(117)
Settlements and curtailments	(44)	(1)
Projected benefit obligation, end of period	1,974	2,049	$ 2,280
Change in plan assets
Fair value of plan assets, beginning of period	1,637	1,759
Actual return on plan assets	177	(9)
Currency exchange rate changes	(80)	(39)
Employer contributions	49	39
Participant contributions	1	4
Benefits paid	(140)	(117)
Settlements	(40)
Fair value of plan assets, end of period	1,604	1,637	1,759
Funded status, end of period	(370)	(412)
Balance sheet classification, end of period:
Pension asset, non-current	5	2
Pension liability, current	(5)	(9)
Pension liability, non-current	(370)	(405)
Accumulated other comprehensive income (loss)	(387)	(375)
Aggregate projected benefit obligation and fair value of plan assets for plans with a projected benefit obligation in excess of plan assets
Projected benefit obligation	1,581	2,049
Fair value of plan assets	1,206	1,637
Aggregate accumulated benefit obligation and fair value of plan assets for plans with an accumulated benefit obligation in excess of plan assets
Accumulated benefit obligation	1,580	1,921
Fair value of plan assets	1,204	1,550
Transocean Plans
Change in projected benefit obligation
Service cost	13	31	68
Interest cost	86	84	91
Change in plan assets
Fair value of plan assets, beginning of period	1,637
Fair value of plan assets, end of period	1,604	1,637
Accumulated benefit obligation for all defined benefit pension plans
Accumulated benefit obligation	2,000	2,000
U.S. Plans
Change in projected benefit obligation
Projected benefit obligation, beginning of period	1,523	1,592
Actuarial (gains) losses, net	52	(71)
Service cost	3	5	39
Interest cost	69	65	64
Benefits paid	(90)	(65)
Settlements and curtailments		(3)
Projected benefit obligation, end of period	1,557	1,523	1,592
Change in plan assets
Fair value of plan assets, beginning of period	1,198	1,271
Actual return on plan assets	93	(21)
Employer contributions	3	13
Benefits paid	(90)	(65)
Fair value of plan assets, end of period	1,204	1,198	1,271
Funded status, end of period	(353)	(325)
Balance sheet classification, end of period:
Pension liability, current	(2)	(3)
Pension liability, non-current	(351)	(322)
Accumulated other comprehensive income (loss)	(316)	(281)
Aggregate projected benefit obligation and fair value of plan assets for plans with a projected benefit obligation in excess of plan assets
Projected benefit obligation	1,557	1,523
Fair value of plan assets	1,204	1,198
Aggregate accumulated benefit obligation and fair value of plan assets for plans with an accumulated benefit obligation in excess of plan assets
Accumulated benefit obligation	1,557	1,523
Fair value of plan assets	1,204	1,198
Non-U.S. Plans
Change in projected benefit obligation
Projected benefit obligation, beginning of period	502	629
Actuarial (gains) losses, net	36	(83)
Service cost	10	26	29
Interest cost	17	19	27
Currency exchange rate changes	(77)	(48)
Participant contributions		1
Benefits paid	(46)	(44)
Settlements and curtailments	(44)	2
Projected benefit obligation, end of period	398	502	629
Change in plan assets
Fair value of plan assets, beginning of period	439	488
Actual return on plan assets	84	12
Currency exchange rate changes	(80)	(39)
Employer contributions	43	21
Participant contributions		1
Benefits paid	(46)	(44)
Settlements	(40)
Fair value of plan assets, end of period	400	439	488
Funded status, end of period	2	(63)
Balance sheet classification, end of period:
Pension asset, non-current	5	2
Pension liability, current		(3)
Pension liability, non-current	(3)	(62)
Accumulated other comprehensive income (loss)	(94)	(119)
Aggregate projected benefit obligation and fair value of plan assets for plans with a projected benefit obligation in excess of plan assets
Projected benefit obligation	5	502
Fair value of plan assets	2	439
Aggregate accumulated benefit obligation and fair value of plan assets for plans with an accumulated benefit obligation in excess of plan assets
Accumulated benefit obligation	4	374
Fair value of plan assets		352
OPEB Plans
Change in projected benefit obligation
Projected benefit obligation, beginning of period	24	59
Actuarial (gains) losses, net	(3)
Service cost		1
Interest cost	1	2
Plan amendments		(33)
Participant contributions	1	3
Benefits paid	(4)	(8)
Projected benefit obligation, end of period	19	24	$ 59
Change in plan assets
Employer contributions	3	5
Participant contributions	1	3
Benefits paid	(4)	(8)
Funded status, end of period	(19)	(24)
Balance sheet classification, end of period:
Pension liability, current	(3)	(3)
Pension liability, non-current	(16)	(21)
Accumulated other comprehensive income (loss)	23	25
Aggregate projected benefit obligation and fair value of plan assets for plans with a projected benefit obligation in excess of plan assets
Projected benefit obligation	19	24
Aggregate accumulated benefit obligation and fair value of plan assets for plans with an accumulated benefit obligation in excess of plan assets
Accumulated benefit obligation	$ 19	$ 24