Recently issued accounting standards (Details)	Jan. 31, 2018 USD ($)
Transaction costs	$ 19,500,000
Station Place on Monmouth, LLC [Member]
Transaction costs	$ 542,000

Amount of direct costs of the business combination including legal, accounting, and other costs incurred to consummate the business acquisition.

No definition available.

Name:	us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant