Segment Information

On January 1, 2017, we classified our investment in 85 Tenth Avenue in the "New York" segment as a result of the December 1, 2016 receipt of a 49.9% ownership interest in the property and prior repayment of our mezzanine loans receivable. Previously our investment in the mezzanine loans was classified in the "Other" segment.

On July 17, 2017, we completed the spin-off of our Washington, DC segment. Beginning in the third quarter of 2017, the historical financial results of our former Washington, DC segment are reflected in our consolidated financial statements as discontinued operations for all periods presented and are included in the Other segment. Subsequent to the Washington, DC spin-off, we operate in two segments, New York and Other, which is based on how we manage our business.

We have reclassified our 49.5% interest in 666 Fifth Avenue Office Condominium from "New York" to "Other" in all periods presented because we do not intend to hold this asset on a long-term basis.

Net Operating Income ("NOI") represents total revenues less operating expenses. We consider NOI to be the primary non-GAAP financial measure for making decisions and assessing the unlevered performance of our segments as it relates to the total return on assets as opposed to the levered return on equity. As properties are bought and sold based on NOI, we utilize this measure to make investment decisions as well as to compare the performance of our assets to that of our peers. NOI should not be considered a substitute for net income. NOI may not be comparable to similarly titled measures employed by other companies.

Below is a reconciliation of net income to NOI for the years ended December 31, 2017, 2016 and 2015.



(Amounts in thousands)	For the Year Ended December 31,
	2017			2016			2015
Net income	$	264,128		$	981,922		$	859,430

Deduct:
Our share of (income) loss from partially owned entities	(15,200		)	(168,948		)	9,947
Our share of (income) loss from real estate fund investments	(3,240		)	23,602			(74,081		)
Interest and other investment income, net	(37,793		)	(29,548		)	(27,240		)
Net gains on disposition of wholly owned and partially owned assets	(501		)	(160,433		)	(149,417		)
Loss (income) from discontinued operations	13,228			(404,912		)	(223,511		)
NOI attributable to noncontrolling interests in consolidated subsidiaries	(65,311		)	(66,182		)	(64,859		)

Add:
Depreciation and amortization expense	429,389			421,023			379,803
General and administrative expense	158,999			149,550			149,256
Acquisition and transaction related costs	1,776			9,451			12,511
NOI from partially owned entities	269,164			271,114			245,750
Interest and debt expense	345,654			330,240			309,298
Income tax expense (benefit)	41,090			7,229			(85,012		)
NOI at share	1,401,383			1,364,108			1,341,875
Non cash adjustments for straight-line rents, amortization of acquired below-market leases, net and other	(86,842		)	(170,477		)	(214,322		)
NOI at share - cash basis	$	1,314,541		$	1,193,631		$	1,127,553

23. Segment Information - continued

Below is a summary of NOI and selected balance sheet data by segment for the years ended December 31, 2017, 2016 and 2015.



(Amounts in thousands)	For the Year Ended December 31, 2017
	Total			New York			Other
Total revenues	$	2,084,126		$	1,779,307		$	304,819
Operating expenses	886,596			756,670			129,926
NOI - consolidated	1,197,530			1,022,637			174,893
Deduct: NOI attributable to noncontrolling interests in consolidated subsidiaries	(65,311		)	(45,899		)	(19,412		)
Add: Our share of NOI from partially owned entities	269,164			189,327			79,837
NOI at share	1,401,383			1,166,065			235,318
Non-cash adjustments for straight-line rents, amortization of acquired below-market leases, net and other	(86,842		)	(79,202		)	(7,640		)
NOI at share - cash basis	$	1,314,541		$	1,086,863		$	227,678
Balance Sheet Data:
Real estate, at cost	$	14,756,295		$	11,025,092		$	3,731,203
Investments in partially owned entities	1,056,829			861,430			195,399
Total assets	17,397,934			13,780,817			3,617,117



(Amounts in thousands)	For the Year Ended December 31, 2016
	Total			New York			Other
Total revenues	$	2,003,742		$	1,713,374		$	290,368
Operating expenses	844,566			716,754			127,812
NOI - consolidated	1,159,176			996,620			162,556
Deduct: NOI attributable to noncontrolling interests in consolidated subsidiaries	(66,182		)	(47,480		)	(18,702		)
Add: Our share of NOI from partially owned entities	271,114			159,386			111,728
NOI at share	1,364,108			1,108,526			255,582
Non-cash adjustments for straight-line rents, amortization of acquired below-market leases, net and other	(170,477		)	(143,239		)	(27,238		)
NOI at share - cash basis	$	1,193,631		$	965,287		$	228,344
Balance Sheet Data:
Real estate, at cost	$	14,187,820		$	10,787,730		$	3,400,090
Investments in partially owned entities	1,378,254			1,026,793			351,461
Total assets	20,814,847			13,310,524			7,504,323



(Amounts in thousands)	For the Year Ended December 31, 2015
	Total			New York			Other
Total revenues	$	1,985,495		$	1,695,925		$	289,570
Operating expenses	824,511			694,228			130,283
NOI - consolidated	1,160,984			1,001,697			159,287
Deduct: NOI attributable to noncontrolling interests in consolidated subsidiaries	(64,859		)	(42,905		)	(21,954		)
Add: Our share of NOI from partially owned entities	245,750			156,177			89,573
NOI at share	1,341,875			1,114,969			226,906
Non-cash adjustments for straight-line rents, amortization of acquired below-market leases, net and other	(214,322		)	(186,781		)	(27,541		)
NOI at share - cash basis	$	1,127,553		$	928,188		$	199,365