CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Trade accounts receivable, allowances for doubtful accounts	$ 9,364	$ 8,713
Other intangible assets, accumulated amortization	$ 87,594	$ 66,412
Shareholders' equity:
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	100,000,000	100,000,000
Common stock, issued (in shares)	14,655,356	14,655,356
Treasury stock (in shares)	264,297	280,195
Series A Preferred Stock [Member]
Shareholders' equity:
Preferred stock, voting rights	1/10th vote per share	1/10th vote per share
Preferred stock, par value (in dollars per share)	$ 1.00	$ 1.00
Preferred stock, liquidation preference (in dollars per share)	$ 112	$ 112
Preferred stock, authorized (in shares)	1,000,000	1,000,000
Preferred stock, issued (in shares)	1,122	1,122
Preferred stock, outstanding (in shares)	1,122	1,122
Series B Convertible Preferred Stock [Member]
Shareholders' equity:
Preferred stock, voting rights	1/10th vote per share	1/10th vote per share
Preferred stock, par value (in dollars per share)	$ 1.00	$ 1.00
Preferred stock, stated value (in dollars per share)	100	100
Preferred stock, liquidation preference (in dollars per share)	$ 1,500	$ 1,500
Preferred stock, authorized (in shares)	1,000,000	1,000,000
Preferred stock, issued (in shares)	15,000	15,000
Preferred stock, outstanding (in shares)	15,000	15,000