Revenues (Tables)

6 Months Ended

Jun. 30, 2021

Revenues

Schedule of revenue disaggregation

	Three months ended June 30, 2021								Three months ended June 30, 2020
	U.S.		Norway		Other		Total		U.S.		Norway		Other		Total
Ultra-deepwater floaters	$	273	$	—	$	151	$	424	$	440	$	—	$	196	$	636
Harsh environment floaters		—		222		10		232		—		207		86		293
Midwater floaters		—		—		—		—		—		—		1		1
Total contract drilling revenues	$	273	$	222	$	161	$	656	$	440	$	207	$	283	$	930

	Six months ended June 30, 2021								Six months ended June 30, 2020
	U.S.		Norway		Other		Total		U.S.		Norway		Other		Total
Ultra-deepwater floaters	$	539	$	—	$	321	$	860	$	727	$	—	$	437	$	1,164
Harsh environment floaters		4		424		21		449		—		414		99		513
Midwater floaters		—		—		—		—		—		—		12		12
Total contract drilling revenues	$	543	$	424	$	342	$	1,309	$	727	$	414	$	548	$	1,689

Schedule of contract balances and changes

	June 30,		December 31,
	2021		2020
Deferred contract revenues, recorded in other current liabilities	$	102	$	133
Deferred contract revenues, recorded in other long-term liabilities		282		323
Total contract liabilities	$	384	$	456

The changes in contract liabilities were as follows (in millions):

	Six months ended
	June 30,
	2021		2020
Total contract liabilities, beginning of period	$	456	$	529
Decrease due to recognition of revenues for goods and services		(81)		(108)
Increase due to goods and services transferred over time		9		98
Total contract liabilities, end of period	$	384	$	519