Consolidated Balance Sheet (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
CURRENT ASSETS
Cash and cash equivalents	$ 83,204	$ 69,531
Accounts receivable less allowances of $12,555 (2012 - $10,892)	80,117	93,333
Inventories	6,729	7,058
Current deferred income taxes	25,101	13,659
Prepaid income taxes	3,538	2,643
Prepaid expenses	17,684	11,447
Total current assets	216,373	197,671
Investments of deferred compensation plans	40,683	36,089
Properties and equipment, at cost, less accumulated depreciation of $178,720 (2012- $164,607)	89,800	91,934
Identifiable intangible assets less accumulated amortization of $31,633 (2012 - $30,414)	56,979	57,177
Goodwill	466,940	465,832
Other assets	10,765	10,923
Total Assets	881,540	859,626
CURRENT LIABILITIES
Accounts payable	44,523	48,472
Current portion of long-term debt	181,340
Income taxes	5,529	4,938
Accrued insurance	41,737	40,654
Accrued compensation	46,689	45,457
Other current liabilities	56,536	17,301
Total current liabilities	376,354	156,822
Deferred income taxes	27,454	27,662
Long-term debt		174,890
Deferred compensation liabilities	39,406	35,599
Other liabilities	11,499	11,362
Total Liabilities	454,713	406,335
Commitments and contingencies
STOCKHOLDERS' EQUITY
Capital stock - authorized 80,000,000 shares $1 par; issued 32,085,561 shares (2012 - 31,589,366 shares)	32,086	31,589
Paid-in capital	469,934	437,364
Retained earnings	666,894	623,035
Treasury stock - 14,548,735 shares (2012 - 13,057,270)	(744,210)	(640,732)
Deferred compensation payable in Company stock	2,123	2,035
Total Stockholders' Equity	426,827	453,291
Total Liabilities and Stockholders' Equity	$ 881,540	$ 859,626