Accounts Payable and Accrued Liabilities - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accounts Payable And Accrued Liabilities [Line Items]
Asset retirement obligation, accretion expense	$ 2.0	$ 2.0	$ 1.8
Basic Management Inc And LandWell | Deferred Payment | Present Value
Accounts Payable And Accrued Liabilities [Line Items]
Discount rate				3.00%
Basic Management Inc And LandWell | Real Estate Management And Development | Deferred Payment | Face Value
Accounts Payable And Accrued Liabilities [Line Items]
Business combination consideration transferred, deferred payment obligation				$ 11.1
Interest rate				3.00%