Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 847	$ 872
Cumulative convertible preferred stock, at par value (in dollars per share)	$ 0.0001	$ 0.0001
Cumulative convertible preferred stock, shares authorized	100,000	100,000
Cumulative convertible preferred stock, shares issued	0	0
Cumulative convertible preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	80,000,000	80,000,000
Common stock, shares issued	54,633,726	58,265,911
Common stock, shares outstanding	53,357,811	51,804,078
Treasury stock, shares	449,397	5,394,178