Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Current assets
Cash and cash equivalents	$ 92,120	$ 162,675
Accounts receivable	123,329	126,853
Inventories	7,411	7,095
Prepaid income taxes	23,386	6,603
Prepaid expenses	22,840	26,177
Total current assets	269,086	329,403
Investments of deferred compensation plans	98,256	88,811
Properties and equipment, at cost, less accumulated depreciation of $307,347 (2020 - $293,380)	192,653	187,820
Lease right of use asset	123,207	123,448
Identifiable intangible assets less accumulated amortization of $52,628 (2020 - $47,607)	113,137	118,085
Goodwill	578,650	578,585
Other assets	8,807	8,759
Total Assets	1,383,796	1,434,911
Current liabilities
Accounts payable	55,975	54,234
Income taxes	5	9,464
Accrued insurance	51,963	54,703
Accrued compensation	83,608	91,282
Accrued legal	1,391	10,632
Short-term lease liability	36,440	36,200
Other current liabilities	38,020	42,593
Total current liabilities	267,402	299,108
Deferred income taxes	21,713	20,664
Deferred compensation liabilities	97,374	88,456
Long-term lease liability	99,093	99,210
Other liabilities	27,440	26,273
Total Liabilities	513,022	533,711
Commitments and contingencies (Note 10)
STOCKHOLDERS' EQUITY
Capital stock - authorized 80,000,000 shares $1 par; issued 36,385,091 shares (2020 - 36,258,638 shares)	36,385	36,259
Paid-in capital	999,697	961,404
Retained earnings	1,834,835	1,723,777
Treasury stock - 20,720,835 shares (2020 - 20,351,562 shares)	(2,002,326)	(1,822,579)
Deferred compensation payable in Company stock	2,183	2,339
Total Stockholders' Equity	870,774	901,200
Total Liabilities and Stockholders' Equity	$ 1,383,796	$ 1,434,911