Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets
Cash and cash equivalents	$ 112,765	$ 6,158
Accounts receivable less allowances of $1,293 (2019 -$353)	110,839	143,827
Inventories	7,546	7,462
Prepaid income taxes	14,224	10,074
Prepaid expenses	25,222	23,150
Total current assets	270,596	190,671
Investments of deferred compensation plans	86,865	77,446
Properties and equipment, at cost, less accumulated depreciation of $288,657 (2019 - $270,140)	181,386	175,763
Lease right of use asset	120,382	111,652
Identifiable intangible assets less accumulated amortization of $45,095 (2019 - $37,620)	120,401	126,370
Goodwill	578,519	577,367
Other assets	8,805	9,048
Total Assets	1,366,954	1,268,317
Current liabilities
Accounts payable	39,268	51,101
Accrued insurance	50,727	50,328
Accrued compensation	101,868	70,814
Accrued legal	9,561	6,941
Short-term lease liability	33,311	39,280
Unutilized CARES Act grant	48,041
Other current liabilities	46,387	43,756
Total current liabilities	329,163	262,220
Deferred income taxes	19,222	18,504
Long-term debt		90,000
Deferred compensation liabilities	86,875	76,446
Long-term lease liability	99,241	86,656
Other liabilities	31,045	7,883
Total Liabilities	565,546	541,709
Commitments and contingencies (Note 11)
STOCKHOLDERS' EQUITY
Capital stock - authorized 80,000,000 shares $1 par; issued 36,137,463 shares (2019 - 35,810,528 shares)	36,137	35,811
Paid-in capital	925,271	860,671
Retained earnings	1,615,465	1,425,752
Treasury stock - 20,261,187 shares (2019 - 19,867,220 shares)	(1,777,809)	(1,597,940)
Deferred compensation payable in Company stock	2,344	2,314
Total Stockholders' Equity	801,408	726,608
Total Liabilities and Stockholders' Equity	$ 1,366,954	$ 1,268,317