Stockholders' Equity - Additional Information (Details)		9 Months Ended
	Feb. 15, 2018 USD ($) director registration member vote $ / shares shares	Sep. 30, 2020 USD ($) vote $ / shares shares	Dec. 31, 2019 $ / shares shares
Class of Stock [Line Items]
Dividends | $		$ 0
Preferred stock, shares issued (in shares) | shares		242,000	242,000
Preferred stock, par value (usd per share) | $ / shares		$ 0.0001	$ 0.0001
Preferred stock, shares outstanding (in shares) | shares		242,000	242,000
Preferred stock, dividends (in shares) | shares		56,671
Dividend rate, percentage	14.50%
Convertible preferred stock, conversion ratio	55.5556
Convertible preferred stock, conversion price per share (usd per share) | $ / shares	$ 18.00
Number of elected directors | director	4
Number of board of director members | director	10
Number of board of director members elected by preferred stock holders | director	2
Number of board of directors agreed upon to be elected meeting independence criteria | director	4
Number of board of directors elected meeting independence criteria | director	2
Minimum number of board of director members that preferred stock holders can appoint pursuant to certification | director	1
Maximum ownership threshold allowed for director election rights, percent	30.00%
Demand registrations allowed under agreement | registration	3
Demand registrations allowed under agreement annually | registration	2
Demand registration, minimum percentage of shares	10.00%
2015 Plan
Class of Stock [Line Items]
Number of shares available for grant (in shares) | shares		600,000
Liability, accrued expenses, non-vested | $		$ 800,000
2017 New Hire Plan
Class of Stock [Line Items]
Number of shares available for grant (in shares) | shares		400,000
Chief Executive Officer
Class of Stock [Line Items]
Number of elected directors | director	1
Board of Directors Chairman
Class of Stock [Line Items]
Number of elected directors | director	1
Ten Percent or Greater Ownership
Class of Stock [Line Items]
Number of elected directors | member	2
Preferred stock, ownership percentage	10.00%
Greater than Five and Less than Ten Percent Ownership
Class of Stock [Line Items]
Number of elected directors | member	1
Greater than Five and Less than Ten Percent Ownership | Minimum
Class of Stock [Line Items]
Preferred stock, ownership percentage	5.00%
Greater than Five and Less than Ten Percent Ownership | Maximum
Class of Stock [Line Items]
Preferred stock, ownership percentage	10.00%
Silver Private Holdings I, LLC
Class of Stock [Line Items]
Preferred stock, shares issued (in shares) | shares	185,000
Preferred stock, par value (usd per share) | $ / shares	$ 0.0001
Preferred stock, liquidation preference (usd per share) | $ / shares	$ 1,000
Consideration received on transaction | $	$ 97,700,000
Number of shares repurchased under program (in shares) | shares	5,994,667
Fair value, approval threshold | $	$ 10,000,000.0
Fair market value of transaction, individual | $	5,000,000.0
Fair market value of transaction, aggregate | $	10,000,000.0
Capital expenditure threshold | $	$ 25,000,000.0
Percentage ownership after conversion	19.90%
Voting percentage threshold of ownership	19.99%
Minimum number of board of director members that preferred stock holders can appoint pursuant to certification | director	2
Common Stock
Class of Stock [Line Items]
Number of votes per share (vote) | vote		1
Series A Preferred Stock
Class of Stock [Line Items]
Number of votes per share (vote) | vote	1
Preferred stock, shares issued (in shares) | shares		185,000
Preferred stock, shares outstanding (in shares) | shares		241,671
Preferred stock, redemption period	30 months
Preferred stock, liquidation preference | $		$ 243,100,000
Preferred stock, redemption amount | $		$ 243,100,000