Commitments (Tables)

12 Months Ended

Dec. 31, 2017

Office buildings and industrial properties

Commitments

Schedule of future minimum lease payments

	Year ending
(in thousands)	December 31,
2018	$	180,321
2019		156,530
2020		139,250
2021		121,185
2022		92,803
Thereafter (2023-2036)		244,075
	$	934,164

Corporate office space

Commitments

Schedule of future minimum lease payments

	Year ending
(in thousands)	December 31,
2018	$	404
2019		412
2020		421
2021		429
2022		438
Thereafter		787
	$	2,891