Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Current assets
Receivables, allowance for doubtful accounts	$ 12,187	$ 11,658
SHAREHOLDERS' DEFICIT
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	160,000,000	160,000,000
Common stock, shares issued	95,345,362	95,345,362
Common stock, shares outstanding	58,638,863	58,171,059
Treasury stock, shares	36,706,499	37,174,303