Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Consolidated Balance Sheets [Abstract]
Allowance for trade accounts receivable	$ 2,420	$ 2,670
Unamortized premium on notes	888	956
Deferred debt costs, net of amortization	$ 23,423	$ 9,704
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	80,000,000	80,000,000
Common stock, shares issued	43,500,032	43,500,032
Common stock, shares outstanding	42,761,426	42,196,680
Treasury stock, shares	738,606	1,303,352