Stockholders’ Equity - Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								6 Months Ended		9 Months Ended		12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jul. 12, 2017
Preferred Stock
Preferred stock, shares authorized	20,000,000				20,000,000								20,000,000	20,000,000
Preferred stock, shares outstanding	4,294,233				4,569,233								4,294,233	4,569,233
Preferred Stock, par value (in dollars per share)	$ 0.0001				$ 0.0001								$ 0.0001	$ 0.0001
Cumulative dividends for Series A Preferred Stock	$ 597	$ 884	$ 914	$ 914	$ 914	$ 914	$ 914	$ 914	$ 1,828	$ 1,828	$ 2,712	$ 2,742	$ 3,309	$ 3,655	$ 2,489
Series A Preferred Stock
Preferred Stock
Preferred stock, shares outstanding	4,294,233				4,569,233								4,294,233	4,569,233
Preferred Stock, par value (in dollars per share)	$ 0.0001												$ 0.0001
Conversion ratio to Common Stock	1.2226												1.2226
Conversion price (in dollars per share)	$ 8.80												$ 8.80
Third anniversary expected liquidation preference (in dollars per share)	$ 10.75911												$ 10.75911
Number of Common Stock issuable upon conversion of all convertible Preferred Shares	11,240,869												11,240,869
Additional common stock issuable upon conversion of remaining convertible shares	5,250,129												5,250,129
Preferred Stock, cumulative dividends rate (in percentage)													10.00%
Cumulative dividends for Series A Preferred Stock													$ 3,300
Cumulative accrued but unpaid dividends																$ 9,400
Per share average of cumulative preferred dividends (in dollars per share)													$ 2.2