Other assets Other assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Acquired below-market ground leases	$ 12,626	$ 12,684
Acquired in-place leases	94,948	64,979
Deferred compensation plan	18,264	15,534
Deferred financing costs – $1.65 billion unsecured senior line of credit	9,596	10,525
Deposits	18,415	10,576
Furniture, fixtures, and equipment	10,904	11,070
Interest rate hedge assets	6,461	5,260
Net investment in direct financing lease	38,574	38,382
Notes receivable	593	614
Prepaid expenses	20,646	10,972
Property, plant, and equipment	42,802	32,073
Other assets	17,810	15,784
Total	$ 291,639	$ 228,453