CONSOLIDATED CONDENSED BALANCE SHEETS (PARENTHETICAL) (USD $) In Thousands, except Share data, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Statement Of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 3,665	$ 3,674
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, authorized	300,000,000	300,000,000
Common stock, issued	189,233,429	186,487,246
Common stock, outstanding	146,414,844	144,219,189
Treasury stock, shares	42,818,585	42,268,057