Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Office rental
Rental revenues	$ 498,214	$ 412,448	$ 396,524
Tenant recoveries	46,847	43,139	44,461
Parking and other income	100,572	85,388	78,420
Total office revenues	645,633	540,975	519,405
Multifamily rental
Rental revenues	89,996	87,907	74,289
Parking and other income	6,922	6,892	5,828
Total multifamily revenues	96,918	94,799	80,117
Total revenues	742,551	635,774	599,522
Operating Expenses
Office expenses	214,546	186,556	181,160
Multifamily expenses	23,317	23,862	20,664
General and administrative	34,957	30,496	27,332
Depreciation and amortization	248,914	205,333	202,512
Total operating expenses	521,734	446,247	431,668
Operating income	220,817	189,527	167,854
Other income	8,759	15,228	17,675
Other expenses	(6,609)	(6,470)	(7,095)
Income, including depreciation, from unconsolidated real estate funds	7,812	7,694	3,713
Interest expense	(146,148)	(135,453)	(128,507)
Acquisition-related expenses	(2,868)	(1,771)	(786)
Income before gains	81,763	68,755	52,854
Gains on sales of investments in real estate	14,327	0	0
Net income	96,090	68,755	52,854
Less: Net income attributable to noncontrolling interests	(10,693)	(10,371)	(8,233)
Net income attributable to common stockholders	$ 85,397	$ 58,384	$ 44,621
Net income attributable to common stockholders per share – basic (dollars per share)	$ 0.569	$ 0.398	$ 0.309
Net income attributable to common stockholders per share – diluted (dollars per share)	$ 0.554	$ 0.386	$ 0.300