Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Trade accounts receivable, allowance for doubtful accounts	$ 5,981	$ 4,148
Common stock, par value	$ 0.01	$ 0.01
Common stock, issued	112,297	112,219
Common stock, outstanding	112,297	112,219