Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Related Party Transaction [Line Items]
Current portion of deferred revenue	$ 12,764	$ 15,554
Long-term portion of deferred revenue	66,360	54,210
Current portion of long-term debt	31,433	559
Long-term debt, less current portion	$ 184,034	$ 211,235
Common stock, shares authorized (in shares)	400,000,000	200,000,000
Common stock, shares issued (in shares)	162,511,940	160,020,466
Common stock, shares outstanding (in shares)	162,511,940	160,020,466
Related Parties, Aggregated
Related Party Transaction [Line Items]
Current portion of deferred revenue	$ 4,205	$ 6,945
Long-term portion of deferred revenue	51,900	52,227
Current portion of long-term debt	30,974	0
Long-term debt, less current portion	$ 25,000	$ 55,290

The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

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