Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2018

Accounting Policies [Abstract]

Summary of Financial Information for Joint Ventures

The following tables present summarized financial information for these joint ventures:

Year Ended December 31			2018		2017
(In millions)
Total assets			$	1,924	$	1,703
Total liabilities				1,451		1,347
Year Ended December 31	2018		2017		2016
Revenues	$	731	$	731	$	693
Net income		114		261		80

Principal Service Lives

The principal service lives used in computing provisions for depreciation are as follows:

	Years
Pipeline equipment		30 to 50
Offshore drilling equipment		15 to 30
Other		3 to 40