Borrowings - Additional Information (Detail) - USD ($)								3 Months Ended	12 Months Ended
		Apr. 30, 2020	Feb. 21, 2020	Dec. 20, 2017	May 09, 2014	Dec. 09, 2013	Oct. 23, 2012	Nov. 30, 2018	May 31, 2020		May 31, 2019		May 31, 2015	May 22, 2020	Feb. 27, 2019	Mar. 02, 2017	May 29, 2015
Debt Instrument [Line Items]
Maturities of long-term debt in 2021									$ 80,900,000
Maturities of long-term debt in 2022									300,000
Maturities of long-term debt in 2023									700,600,000
Maturities of long-term debt in 2024									419,300,000
Maturities of long-term debt in 2025									0.0
Maturities of long-term debt thereafter									1,338,100,000
Credit facility, available liquidity									1,046,900,000
Liquidity available									$ 1,280,400,000
Consolidated indebtedness									66.80%		64.20%
Credit facility borrowing potential maximum capacity									$ 1,500,000,000
Convertible Notes
Debt Instrument [Line Items]
Debt, interest rate						2.25%
Note Interest payment frequency, term									Interest on the Convertible Notes semi-annually on June 15th and December 15th of each year
Notes maturity date						2020
Issuance of Debt
Debt Instrument [Line Items]
Covenant leverage ratio									425.00%
Accounts Receivable Securitization Program with Two Banks, through May 21, 2021
Debt Instrument [Line Items]
Credit facility borrowing maximum capacity					$ 200,000,000.0				$ 250,000,000.0					$ 250,000,000.0
Credit facility expiration date					May 21, 2021
Percentage of indirect economic interest held in SPE					100.00%
Outstanding balance									$ 80,000,000.0
Unsecured senior notes, maturity date									May 21, 2021		May 21, 2021
Unsecured 3.45% senior notes due November 15, 2022
Debt Instrument [Line Items]
Issuance of note							$ 300,000,000		$ 300,000,000.0		$ 300,000,000.0
Debt, interest rate							3.45%		3.45%		3.45%
Proceeds from issuance of note							$ 297,700,000
Unsecured senior notes, maturity date									Nov. 15, 2022		Nov. 15, 2022
Unsecured 5.25% notes due June 1, 2045
Debt Instrument [Line Items]
Issuance of note																$ 50,000,000.0	$ 250,000,000
Debt, interest rate									5.25%	[1]	5.25%	[1]				5.25%	5.25%
Note Interest payment frequency, term									Interest on the 2045 Notes is payable semiannually in arrears on June 1st and December 1st of each year at a rate of 5.250% per year
Unsecured senior notes, maturity date	[1]								Jun. 01, 2045		Jun. 01, 2045
Unsecured 3.75% notes due March 15, 2027
Debt Instrument [Line Items]
Issuance of note									$ 400,000,000.0		$ 400,000,000.0					$ 400,000,000.0
Debt, interest rate									3.75%	[2]	3.75%	[2]				3.75%
Note Interest payment frequency, term									Interest on the 2027 Notes is payable semiannually in arrears on March 15th and September 15th of each year, at a rate of 3.750% per year
Unsecured senior notes, maturity date	[2]								Mar. 15, 2027		Mar. 15, 2027
Unsecured 4.55% senior notes due March 1, 2029
Debt Instrument [Line Items]
Issuance of note									$ 350,000,000.0		$ 350,000,000.0				$ 350,000,000.0
Debt, interest rate									4.55%	[3]	4.55%	[3]			4.55%
Note Interest payment frequency, term									Interest on the 2029 Notes accrues from February 27, 2019 and is payable semiannually in arrears on March 1st and September 1st of each year, beginning September 1, 2019, at a rate of 4.550% per year.
Unsecured senior notes, maturity date	[3]								Mar. 01, 2029		Mar. 01, 2029
Unsecured 4.25% notes due January 15, 2048
Debt Instrument [Line Items]
Issuance of note				$ 300,000,000.0					$ 300,000,000.0		$ 300,000,000.0
Debt, interest rate				4.25%					4.25%	[4]	4.25%	[4]
Note Interest payment frequency, term									Interest on the 2048 Notes accrues from December 20, 2017 and is payable semiannually in arrears on January 15th and July 15th of each year, beginning July 15, 2018, at a rate of 4.250% per year.
Unsecured senior notes, maturity date	[4]								Jan. 15, 2048		Jan. 15, 2048
Unsecured 6.50% senior notes due February 15, 2018
Debt Instrument [Line Items]
Debt, interest rate				6.50%
Unsecured senior notes, maturity date									Feb. 15, 2018
Repayments of unsecured senior notes				$ 250,000,000.0
Unsecured 2.25% Convertible Senior Notes due December 15, 2020
Debt Instrument [Line Items]
Issuance of note									$ 205,000,000.0
Debt instrument, redemption price, percentage									100.00%
Debt instrument, conversion rate									19,221.062000
Debt instrument, conversion of common stock, debt amount									$ 1,000
Debt instrument, conversion price									$ 52.12
Debt conversion, description									The Convertible Notes became convertible at any time prior to the close of business on November 26, 2018
Settlement of convertible notes in cash									$ 204,600,000
Number of shares issued to settle convertible notes									598,601
Unsecured 2.25% Convertible Senior Notes due December 15, 2020 | Convertible Notes
Debt Instrument [Line Items]
Issuance of note						$ 205,000,000
Minimum | Issuance of Debt
Debt Instrument [Line Items]
Covenant leverage ratio									375.00%
Aggregate consideration for acquisition									$ 100,000,000.0
Interest coverage ratio									350.00%
Minimum | Accounts Receivable Securitization Program with Two Banks, through May 21, 2021
Debt Instrument [Line Items]
Monthly unused commitment fee									0.30%
Maximum | Accounts Receivable Securitization Program with Two Banks, through May 21, 2021
Debt Instrument [Line Items]
Monthly unused commitment fee									0.50%
Margin
Debt Instrument [Line Items]
Basis spread on variable rate									0.95%
Revolving Credit Facility
Debt Instrument [Line Items]
Credit facility, available liquidity									$ 877,000,000.0
Credit facility borrowing maximum capacity								$ 1,300,000,000					$ 800,000,000.0
Credit facility expiration date								Oct. 31, 2023					Dec. 05, 2019
Payment of basis point fee		0.10%
Interest coverage ratio									831.00%
Leverage ratio									289.00%
Unsecured senior notes, maturity date	[5]								Oct. 31, 2023		Oct. 31, 2023
Revolving Credit Facility | Minimum
Debt Instrument [Line Items]
Covenant leverage ratio		375.00%
Acquisition aggregate consideration		$ 100,000,000.0
Revolving Credit Facility | Maximum
Debt Instrument [Line Items]
Covenant leverage ratio		425.00%
Revolving Credit Facility | Euro-Rate | Investment Grade
Debt Instrument [Line Items]
Basis spread on variable rate		1.75%
Revolving Credit Facility | Euro-Rate | Non-Investment Grade
Debt Instrument [Line Items]
Basis spread on variable rate		2.00%
Revolving Credit Facility | Base Rate | Investment Grade
Debt Instrument [Line Items]
Basis spread on variable rate		0.75%
Revolving Credit Facility | Base Rate | Non-Investment Grade
Debt Instrument [Line Items]
Basis spread on variable rate		1.00%
New Credit Facility
Debt Instrument [Line Items]
Credit facility expiration date			Feb. 21, 2023
Debt, interest rate			0.612%
New Credit Facility | Foreign Borrower
Debt Instrument [Line Items]
Debt, interest rate			0.558%
New Credit Facility | Issuance of Debt
Debt Instrument [Line Items]
Covenant leverage ratio									375.00%
New Credit Facility | Term Loan
Debt Instrument [Line Items]
Credit facility borrowing maximum capacity			$ 300,000,000
New Credit Facility | Term Loan | Foreign Borrower
Debt Instrument [Line Items]
Credit facility borrowing maximum capacity			$ 100,000,000
New Credit Facility | Minimum | Issuance of Debt
Debt Instrument [Line Items]
Aggregate consideration for acquisition									$ 50,000,000
Interest coverage ratio									350.00%
New Credit Facility | Maximum | Issuance of Debt
Debt Instrument [Line Items]
Covenant leverage ratio		425.00%							425.00%

[1] The $250.0 million face amount of the notes due 2045 is adjusted for the amortization of the original issue discount, which approximated $1.4 million at May 31, 2020 and 2019. The original issue discount effectively reduced the ultimate proceeds from the financing. The effective interest rate on the notes, including the amortization of the discount, is 5.29%. In March 2017, as a further issuance of the 5.25% notes due 2045, we closed an offering of $50.0 million aggregate principal, which is adjusted for the unamortized premium received at issuance, which approximated $2.9 million and $3.0 million at May 31, 2020 and 2019, respectively.  The premium effectively increased the proceeds from the financing.  The effective interest rate on the $50.0 million notes issued March 2017 is 4.839%.  At May 31, 2020 and 2019, the notes are adjusted for debt issuance costs, net of amortization, for approximately $2.9 million and $3.0 million, respectively.

[2] The $400.0 million face amount of the notes due 2027 is adjusted for the amortization of the original issue discount, which approximated $0.3 million and $0.4 million at May 31, 2020 and 2019, respectively.  The original issue discount effectively reduced the ultimate proceeds from the financing.  The effective interest rate on the notes, including the amortization of the discount, is 3.767%.  At May 31, 2020 and 2019, the notes are adjusted for debt issuance costs, net of amortization, for approximately $2.6 million and $3.0 million, respectively.

[3] The $350.0 million aggregate principal amount of the notes due 2029 is adjusted for the amortization of the original issue discount, which approximated $0.5 million at May 31, 2020 and 2019. The original issue discount effectively reduced the ultimate proceeds from the financing. The effective interest rate on the notes, including the amortization of the discount, was 4.568%.  At May 31, 2020 and 2019, the notes were adjusted for debt issuance costs, net of amortization, for approximately $3.0 million and $3.5 million, respectively.

[4] The $300.0 million face amount of the notes due 2048 is adjusted for the debt issuance cost, net of amortization, which approximated $3.4 million and $3.5 million at May 31, 2020 and 2019, respectively. The effective interest rate on the notes is 4.25%.

[5] Interest at May 31, 2020 was tied to LIBOR and averaged 1.5505% for USD denominated debt ($218,281), 1.4650% for AUD denominated debt ($37,199) and 1.3750% on EUR denominated debt ($167,537).  Interest at May 31, 2019 was tied to LIBOR and averaged 3.6805% for USD denominated debt ($14,268), 2.69% for AUD denominated debt ($34,558), 3.23% on CAD denominated debt ($131,738) and 1.25% on EUR denominated debt ($159,745).  At May 31, 2020 and 2019, the revolving credit facility is adjusted for debt issuance costs, net of amortization, for approximately $3.7 million and $3.9 million, respectively.