Notes and Contracts Payable (Narrative) (Detail) - USD ($) $ in Millions		1 Months Ended	12 Months Ended
	Feb. 01, 2023	May 31, 2023	Dec. 31, 2023	Apr. 30, 2023
Debt Instrument [Line Items]
Fixed interest rate			2.10%
Line Of Credit Facility Maximum Increase In Revolving Credit Expansion Option		$ 450.0
Long-term Line of Credit			$ 0.0
Revolving loans, interest rate description			At the Company’s election, borrowings of revolving loans under the credit agreement bear interest at (a) the Alternate Base Rate plus the applicable spread, (b) the Adjusted Term SOFR Rate plus the applicable spread, or (c) the Adjusted Daily Simple SOFR plus the applicable spread (in each case as defined in the credit agreement). The Company may select interest periods of one, three or six months for Adjusted Term SOFR Rate borrowings of loans. The applicable spread varies depending upon the Debt Rating assigned by Moody’s Investor Service, Inc., Standard & Poor's Rating Services and/or Fitch Ratings Inc. The minimum applicable spread for Alternate Base Rate borrowings is 0.125% and the maximum is 0.75%. The minimum applicable spread for Adjusted Term SOFR Rate and Adjusted Daily Simple SOFR borrowings is 1.125% and the maximum is 1.75%. The Alternate Base Rate is subject to a floor of 1.00% and the Adjusted Term SOFR Rate and the Adjusted Daily Simple SOFR are each subject to a floor of 0.00%. The rate of interest on any term loans incurred in connection with the expansion option will be established at or about the time such loans are made and may differ from the rate of interest on revolving loans.
Line of Credit Facility, Covenant Compliance			The credit agreement includes representations and warranties, reporting covenants, affirmative covenants, negative covenants, financial covenants and events of default customary for financings of this type. Upon the occurrence of an event of default the lenders may accelerate the loans. Upon the occurrence of certain insolvency and bankruptcy events of default the loans will automatically accelerate. As of December 31, 2023, the Company was in compliance with the financial covenants under the credit agreement.
Unsecured Debt | JPMorgan Chase Bank, N.A
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 900.0		$ 700.0
Line of Credit Facility, Expiration Date		May 17, 2028
2.40% unsecured notes
Debt Instrument [Line Items]
Fixed interest rate	4.30%
Debt repaid	$ 250.0