Common stock, treasury stock and warrants	6 Months Ended
Jun. 30, 2019
Equity [Abstract]
Common stock, treasury stock and warrants	Common stock, treasury stock and warrants Common stock As of June 30, 2019 and December 31, 2018, the number of issued shares of common stock was 78,534,774 and 76,525,581, respectively, which included shares of treasury stock of 1,785,489 and 1,233,198, respectively. For the six months ended June 30, 2019, the change in the number of issued shares of common stock was a result of an aggregate 2,009,193 shares of common stock issued upon vesting of RSUs, including 552,291 shares of common stock withheld to cover statutory taxes upon such vesting, which are reflected in treasury stock, discussed below. Treasury stock As of June 30, 2019 and December 31, 2018, the Company held shares of treasury stock of 1,785,489 and 1,233,198, with a cost of $6,351 and $3,272, respectively. The Company's share-based incentive plans, discussed in Note 10, Share-based compensation, allow employees to forfeit shares of common stock to satisfy federal and state statutory tax withholding obligations associated with equity awards. The forfeited shares of common stock may be taken into treasury stock by the Company or sold on the open market. For the six months ended June 30, 2019, 552,291 shares of common stock were withheld to cover statutory taxes owed by certain employees for this purpose and taken into treasury stock. Warrants As of June 30, 2019 and December 31, 2018, warrants to purchase an aggregate of 2,398,776 and 2,498,776 shares of common stock were outstanding, respectively, with exercise prices ranging from $3.75 to $6.00 per share. On July 9, 2018 the Company entered into First Amendments (the "First Amendments") to the Amendments to Warrants and Agreements to Exercise ("Amended Whitehorse Warrants") with (i) H.I.G. Whitehorse SMA ABF, L.P. regarding 46,667 warrants to purchase common stock of the Company, par value $0.0005 per share, at an exercise price of $3.00 per share; (ii) H.I.G. Whitehorse SMA Holdings I, LLC regarding 66,666 warrants to purchase common stock of the Company at an exercise price of $3.00 per share; and (iii) Whitehorse Finance, Inc. regarding 186,667 warrants to purchase common stock of the Company at an exercise price of $3.00 per share. In November 2017, the Amended Whitehorse Warrants were exercised and the Company issued an aggregate of 300,000 shares of common stock of the Company (the "Warrant Shares") to the warrant holders. Pursuant to the First Amendments, the warrant holders have the right, but not the obligation, to require the Company to purchase from these warrant holders the 300,000 Warrant Shares at $3.8334 per share (the "Put Right"), which may be exercised during the period commencing January 1, 2019 and ending December 15, 2019. In accordance with ASC 480, Distinguishing Liabilities from Equity, the Put Right has historically been classified within other current liabilities on the condensed consolidated balance sheets because the market price of the Company's common stock has been lower than the exercise price of $3.8334 per share. During the first quarter of 2019, the last reported sale price of the Company's common stock was higher than the exercise price, resulting in the reclassification of the Put Right totaling $1,150 from other current liabilities to equity, and now remains within additional paid-in capital on the condensed consolidated balance sheet as of June 30, 2019.

Common stock, treasury stock and warrants

Common stock

As of June 30, 2019 and December 31, 2018, the number of issued shares of common stock was 78,534,774 and 76,525,581, respectively, which included shares of treasury stock of 1,785,489 and 1,233,198, respectively.

For the six months ended June 30, 2019, the change in the number of issued shares of common stock was a result of an aggregate 2,009,193 shares of common stock issued upon vesting of RSUs, including 552,291 shares of common stock withheld to cover statutory taxes upon such vesting, which are reflected in treasury stock, discussed below.

Treasury stock

As of June 30, 2019 and December 31, 2018, the Company held shares of treasury stock of 1,785,489 and 1,233,198, with a cost of $6,351 and $3,272, respectively.

The Company's share-based incentive plans, discussed in Note 10, Share-based compensation, allow employees to forfeit shares of common stock to satisfy federal and state statutory tax withholding obligations associated with equity awards. The forfeited shares of common stock may be taken into treasury stock by the Company or sold on the open market. For the six months ended June 30, 2019, 552,291 shares of common stock were withheld to cover statutory taxes owed by certain employees for this purpose and taken into treasury stock.

Warrants

As of June 30, 2019 and December 31, 2018, warrants to purchase an aggregate of 2,398,776 and 2,498,776 shares of common stock were outstanding, respectively, with exercise prices ranging from $3.75 to $6.00 per share.

On July 9, 2018 the Company entered into First Amendments (the "First Amendments") to the Amendments to Warrants and Agreements to Exercise ("Amended Whitehorse Warrants") with (i) H.I.G. Whitehorse SMA ABF, L.P. regarding 46,667 warrants to purchase common stock of the Company, par value $0.0005 per share, at an exercise price of $3.00 per share; (ii) H.I.G. Whitehorse SMA Holdings I, LLC regarding 66,666 warrants to purchase common stock of the Company at an exercise price of $3.00 per share; and (iii) Whitehorse Finance, Inc. regarding 186,667 warrants to purchase common stock of the Company at an exercise price of $3.00 per share. In November 2017, the Amended Whitehorse Warrants were exercised and the Company issued an aggregate of 300,000 shares of common stock of the Company (the "Warrant Shares") to the warrant holders. Pursuant to the First Amendments, the warrant holders have the right, but not the obligation, to require the Company to purchase from these warrant holders the 300,000 Warrant Shares at $3.8334 per share (the "Put Right"), which may be exercised during the period commencing January 1, 2019 and ending December 15, 2019. In accordance with ASC 480, Distinguishing Liabilities from Equity, the Put Right has historically been classified within other current liabilities on the condensed consolidated balance sheets because the market price of the Company's common stock has been lower than the exercise price of $3.8334 per share. During the first quarter of 2019, the last reported sale price of the Company's common stock was higher than the exercise price, resulting in the reclassification of the Put Right totaling $1,150 from other current liabilities to equity, and now remains within additional paid-in capital on the condensed consolidated balance sheet as of June 30, 2019.