CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
CONDENSED CONSOLIDATED BALANCE SHEETS
Trade accounts receivable, allowance for doubtful accounts (in dollars)	$ 4,466	$ 4,379
Other intangibles, accumulated amortization (in dollars)	$ 115,219	$ 108,933
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, shares authorized	2,000,000	2,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	40,830,651	40,298,852
Common stock, shares outstanding	35,899,726	34,991,629
Treasury stock, shares	4,930,925	5,307,223