Revenues

3 Months Ended

Mar. 31, 2021

Revenues

Revenues

Note 5—Revenues

Overview—The duration of our performance obligation varies by contract.  As of March 31, 2021, the drilling contract with the longest expected remaining duration, excluding unexercised options, extends through February 2028.  In the three months ended March 31, 2021 and 2020, we recognized pre-operating costs of $14 million and $9 million, respectively, recorded in operating and maintenance costs and expenses.  At March 31, 2021 and December 31, 2020, the carrying amount of our unrecognized pre-operating costs to obtain contracts was $14 million and $20 million, respectively, recorded in other assets.

Disaggregation—Our contract drilling revenues, disaggregated by asset group and by country in which they were earned, were as follows (in millions):

	Three months ended March 31, 2021								Three months ended March 31, 2020
	U.S.		Norway		Other		Total		U.S.		Norway		Other		Total
Ultra-deepwater floaters	$	266	$	—	$	170	$	436	$	287	$	—	$	241	$	528
Harsh environment floaters		4		202		11		217		—		207		13		220
Midwater floaters		—		—		—		—		—		—		11		11
Total contract drilling revenues	$	270	$	202	$	181	$	653	$	287	$	207	$	265	$	759

Contract liabilities—The contract liabilities for our contracts with customers were as follows (in millions):

	March 31,		December 31,
	2021		2020
Deferred contract revenues, recorded in other current liabilities	$	115	$	133
Deferred contract revenues, recorded in other long-term liabilities		304		323
Total contract liabilities	$	419	$	456

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

	Three months ended
	March 31,
	2021		2020
Total contract liabilities, beginning of period	$	456	$	529
Decrease due to recognition of revenues for goods and services		(44)		(41)
Increase due to goods and services transferred over time		7		46
Total contract liabilities, end of period	$	419	$	534