Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Statement Of Financial Position [Abstract]
Allowances for accounts receivable	$ 16,425	$ 13,267
Accumulated amortization of intangibles	$ 54,752	$ 48,340
Preferred stock, par value	$ 1	$ 1
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	300,000,000	300,000,000
Common stock, shares issued	87,850,292	87,850,292
Treasury stock, shares	24,537,168	24,691,431