CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Statement of Financial Position [Abstract]
Trade accounts receivable, allowances (in dollars)	$ 25,068	$ 25,086
Accumulated depreciation	99,473	69,580
Accumulated amortization	$ 24,140	$ 16,164
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized shares	125,000,000	125,000,000
Common stock, issued shares	34,618,000	34,400,000
Common stock, outstanding shares	34,618,000	34,400,000