Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 4,973	$ 2,925
Common stock, shares issued	157,654,235	153,557,108
Common stock, shares outstanding	157,654,235	153,557,108
Common stock, par value (in usd per share)	$ 0.10	$ 0.10
Common stock, shares authorized	200,000,000	200,000,000