Leases - Summary of Recapture Rights Exercised by the Company (Parenthetical) (Detail)	Jun. 30, 2018	May 31, 2018	Mar. 31, 2018	Jul. 31, 2017
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
San Diego, CA [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Percentage of joint ventures ownership interest retained		50.00%
Santa Monica, CA [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Percentage of joint ventures ownership interest retained			50.10%
Wayne, NJ [Member]
Property Subject to or Available for Operating Lease [Line Items]
Percentage of joint ventures ownership interest retained				50.00%
West Hartford, CT [Member]
Property Subject to or Available for Operating Lease [Line Items]
Recapture Type, Percentage	100.00%
Percentage of joint ventures ownership interest retained		50.00%