CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Assets
Accounts receivable, allowance for doubtful accounts (in dollars)	$ 1,734	$ 1,757
Deposits and other assets, restricted (in dollars)	128	355
Liabilities and stockholders' equity
Installment payment agreement, discount	$ 204	$ 678
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	75,000,000	75,000,000
Common stock, shares issued	45,478,787	45,198,718
Common stock, shares outstanding	45,478,787	45,198,718
2022 Notes
Liabilities and stockholders' equity
Unamortized debt costs	$ 2,257	$ 1,252
Unamortized debt premium	462
2021 Notes
Liabilities and stockholders' equity
Unamortized debt costs	$ 2,575	$ 3,305