CONSOLIDATED BALANCE SHEETS CONSOLIDATED BALANCE SHEETS (PARENTHETICAL) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Accounts receivable, allowance for doubtful accounts	$ 14,116	$ 10,322
Common stock, par value, (in dollar per share)	$ 0.008	$ 0.008
Common stock, authorized shares (in shares)	1,000,000,000	1,000,000,000
Common stock, shares issued (in shares)	61,265,160	58,055,586
Treasury stock, shares (in shares)	9,256,721	8,184,787