Consolidated Balance Sheet (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Consolidated Balance Sheet [Abstract]
Accounts receivable, allowances	$ 13,631	$ 13,244
Properties and equipment, at cost, accumulated depreciation	206,922	201,094
Identifiable intangible assets, accumulated amortization	$ 32,960	$ 32,866
Capital stock - authorized	80,000,000	80,000,000
Capital stock - par value	$ 1	$ 1
Capital stock - issued	34,076,407	33,985,316
Treasury stock	17,618,767	17,187,540