Mandatorily Redeemable Series A Preferred Stock	12 Months Ended
Dec. 31, 2017
Equity [Abstract]
Mandatorily Redeemable Series A Preferred Stock	13. Mandatorily Redeemable Series A Preferred Stock On September 13, 2011, the Company entered into a financing agreement with an investor (the “Series A Investor”). The agreement provided for the sale of Series A Preferred Stock (“Series A Preferred Stock”) to the Series A Investor in multiple tranches. As part of this agreement, the Series A Investor received 22 shares of Series A Preferred Stock with an issuance price of $1,000 per share as well as 14,300 shares of common stock in exchange for gross proceeds of $22,000 in September 2011. The second tranche of 26 shares of Series A Preferred Stock was issued in January 2012, in exchange for gross proceeds of $26,000. Dividends accrued and accumulated on the Series A Preferred Stock, whether or not earned or declared, at the rate of 15% per annum and compound quarterly on April 1, July 1, October 1 and January 1. Dividends were paid in-kind with additional Series A Preferred Stock; fractional share portions of calculated dividends were paid in cash. In-kind dividends are accounted for as interest expense and were accrued as part of the long-term liability in the consolidated balance sheets. The Company issued $0, $4,776 and $4,865 Series A Preferred Stock for dividends in December 31, 2017, 2016 and 2015, respectively. The Company incurred $0, $5,624 and $5,652 of interest expense related to the Series A Preferred Stock for the years ended December 31, 2017, 2016 and 2015, respectively. Of this expense, $0, $59 and $574 was capitalized into property, plant and equipment in the consolidated balance sheet at December 31, 2017, 2016 and 2015, respectively. On November 9, 2016, the Series A Preferred Stock was fully redeemed at a total redemption value of $40,329 using a portion of the proceeds from the IPO.

13. Mandatorily Redeemable Series A Preferred Stock

On September 13, 2011, the Company entered into a financing agreement with an investor (the “Series A Investor”). The agreement provided for the sale of Series A Preferred Stock (“Series A Preferred Stock”) to the Series A Investor in multiple tranches. As part of this agreement, the Series A Investor received 22 shares of Series A Preferred Stock with an issuance price of $1,000 per share as well as 14,300 shares of common stock in exchange for gross proceeds of $22,000 in September 2011. The second tranche of 26 shares of Series A Preferred Stock was issued in January 2012, in exchange for gross proceeds of $26,000.

Dividends accrued and accumulated on the Series A Preferred Stock, whether or not earned or declared, at the rate of 15% per annum and compound quarterly on April 1, July 1, October 1 and January 1. Dividends were paid in-kind with additional Series A Preferred Stock; fractional share portions of calculated dividends were paid in cash. In-kind dividends are accounted for as interest expense and were accrued as part of the long-term liability in the consolidated balance sheets. The Company issued $0, $4,776 and $4,865 Series A Preferred Stock for dividends in December 31, 2017, 2016 and 2015, respectively. The Company incurred $0, $5,624 and $5,652 of interest expense related to the Series A Preferred Stock for the years ended December 31, 2017, 2016 and 2015, respectively. Of this expense, $0, $59 and $574 was capitalized into property, plant and equipment in the consolidated balance sheet at December 31, 2017, 2016 and 2015, respectively.

On November 9, 2016, the Series A Preferred Stock was fully redeemed at a total redemption value of $40,329 using a portion of the proceeds from the IPO.