New Accounting Standards (Adoption of New Standard) (Details) - USD ($) $ in Thousands		Sep. 30, 2022	Dec. 31, 2021
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets		$ 190,860	$ 160,567
Total assets		16,130,668	14,699,924
Current portion of operating lease liabilities		34,526	38,017
Total current liabilities		1,378,667	1,232,746
Long-term portion of operating lease liabilities		163,848	129,628
Deferred income taxes		986,252	850,921
Total liabilities		9,187,298	7,706,379
Retained earnings		3,520,446	3,056,845
Total liabilities and equity		16,130,668	14,699,924
Revolving Credit Facility [Member] | Credit Agreement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Long term debt	[1]	738,165	803,944
Revolving Credit Facility [Member] | LIBOR [Member] | Credit Agreement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Long term debt		601,000	631,000
Revolving Credit Facility [Member] | Base Rate [Member] | Credit Agreement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Long term debt		0	158,000
Revolving Credit Facility [Member] | Canadian Bankers Acceptance Loan [Member] | Credit Agreement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Long term debt		137,165	3,944
Term Loan Facility [Member] | Credit Agreement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Long term debt	[1]	650,000	$ 650,000
Term Loan Facility [Member] | Revolving Credit Facility [Member] | LIBOR [Member] | Credit Agreement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Long term debt		$ 1,251,000

[1] Interest rates represent the interest rates in effect at September 30, 2022