CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Receivables, allowances	$ 5,045	$ 4,806
Other noncurrent assets at fair value		$ 33,824
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Common stock, par value	$ 0.005	$ 0.005
Common stock, shares authorized	280,000,000	280,000,000
Common stock, shares issued	140,525,055	139,820,388
Treasury stock, shares	21,491,285	24,182,584