Major Clients (Tables)

12 Months Ended

Dec. 31, 2019

Major Clients

Schedule of sales to major clients, as a percentage of operating revenues

	Year Ended December 31,
		2019	2018	2017
A		18%	—	—
B		16%	—	—
C		15%	10%	—
D		11%	—	—
E		—	22%	17%
F		—	—	10%