Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Condensed Consolidated Balance Sheets
Trade accounts receivable, allowances (in dollars)	$ 15,651	$ 25,086
Property and equipment, accumulated depreciation	75,535	69,580
Other intangible assets, accumulated amortization	$ 18,180	$ 16,164
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized shares	125,000	125,000
Common stock, issued shares	34,447	34,400
Common stock, outstanding shares	34,447	34,400