Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Related Party Transaction [Line Items]
Credit losses, trade receivables	$ 5,725	$ 5,201
Current portion of deferred revenue	11,141	5,697
Long-term portion of deferred revenue	32,877	48,136
Current portion of long-term debt	31,886	31,670
Long-term debt, less current portion	$ 188,730	$ 186,321
Common stock, shares authorized (in shares)	400,000,000	400,000,000
Common stock, shares issued (in shares)	170,656,834	163,274,880
Common stock, shares outstanding (in shares)	170,656,834	163,274,880
Related Parties, Aggregated
Related Party Transaction [Line Items]
Credit losses, related party receivables	$ 2,312	$ 2,312
Current portion of deferred revenue	0	877
Long-term portion of deferred revenue	31,020	30,182
Current portion of long-term debt	31,446	31,211
Long-term debt, less current portion	$ 25,000	$ 25,000