Revenue (Tables)

6 Months Ended

Jun. 30, 2020

Revenue from Contract with Customer [Abstract]

Disaggregation of Revenue [Table Text Block]

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2020		2019		2020		2019
Revenue recognized over time	$	1,439	$	1,496	$	2,914	$	2,861
Revenue recognized at a point in time	1,250		1,539		2,532		2,929
Total revenue	$	2,689	$	3,035	$	5,446	$	5,790

Net Contract Assets and Liabilities

Net contract assets were as follows:

	June 30, 2020		December 31, 2019
Contract assets included in prepaid and other current assets	$	52	$	30
Contract liabilities included in accrued liabilities	(3)		(5)
Net contract asset	$	49	$	25