CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Statement of Financial Position [Abstract]
Receivables, allowance for doubtful accounts	$ 34,560	$ 31,328
Other intangible assets, accumulated amortization	$ 14,108	$ 9,708
Preferred stock, par value	$ 0.10	$ 0.10
Preferred stock, shares authorized	20,000,000	20,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.10	$ 0.10
Common stock, shares authorized	480,000,000	480,000,000
Common stock, shares issued	178,695,000	177,312,000
Common stock, shares outstanding	161,327,000	163,441,000
Treasury stock, shares	17,368,000	13,871,000