CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Statement Of Financial Position [Abstract]
Receivables, allowances	$ 4,722	$ 4,459
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.005	$ 0.005
Common stock, shares authorized	280,000,000	280,000,000
Common stock, shares issued	139,820,388	139,820,388
Treasury stock, shares	25,736,694	23,255,421