Consolidated Balance Sheet (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Consolidated Balance Sheet [Abstract]
Accounts receivable, allowances	$ 14,769	$ 13,244
Properties and equipment, at cost, accumulated depreciation	205,323	201,094
Identifiable intangible assets, accumulated amortization	$ 33,051	$ 32,866
Capital stock - authorized	80,000,000	80,000,000
Capital stock - par value	$ 1	$ 1
Capital stock - issued	34,104,899	33,985,316
Treasury stock	18,014,005	17,187,540