Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Condensed Consolidated Balance Sheets
Trade accounts receivable, allowances (in dollars)	$ 12,474	$ 25,086
Property and equipment, accumulated depreciation	82,210	69,580
Other intangible assets, accumulated amortization	$ 19,936	$ 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	34,493	34,400
Common stock, outstanding shares	34,493	34,400