Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Allowance for trade accounts receivable	$ 1,573	$ 1,838
Current portion of long-term debt, discounts	359	479
Discounts and deferred debt costs	$ 10,448	$ 10,690
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorize	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	80,000,000	80,000,000
Common stock, shares issued	27,267,899	26,990,034
Common stock, shares outstanding	26,957,350	26,747,712
Treasury stock, shares	310,549	242,322