Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2011
Assets, Current [Abstract]
Allowance for doubtful accounts	$ 702	$ 749
Stockholders' Equity Attributable to Parent [Abstract]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	75,000,000	75,000,000
Common stock, shares issued (in shares)	64,585,208	64,130,056
Common stock, shares outstanding (in shares)	64,585,208	64,130,056
Preferred Stock [Member]
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock, shares authorized (in shares)	20,000,000	20,000,000
Series A Junior Participating Preferred Stock [Member]
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock, shares authorized (in shares)	75,000	75,000