Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Current assets:
Allowance for doubtful accounts	$ 3,564	$ 3,970
Accumulated amortization of other intangible assets	$ 12,161	$ 10,078
STOCKHOLDERS’ EQUITY:
Common stock, par value (dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	71,690,000	70,036,000
Common stock, shares outstanding	71,690,000	70,036,000
Common stock in treasury, shares	1,900,000	1,983,000