As of September 30, 2018, the Company owns and manages properties within five segments: (1) Philadelphia Central Business District (Philadelphia CBD), (2) Pennsylvania Suburbs, (3) Metropolitan Washington, D.C., (4) Austin, Texas and (5) Other. The Philadelphia CBD segment includes properties located in the City of Philadelphia in Pennsylvania. The Pennsylvania Suburbs segment includes properties in Chester, Delaware, and Montgomery counties in the Philadelphia suburbs. The Metropolitan Washington, D.C. segment includes properties in the District of Columbia, Northern Virginia and southern Maryland. The Austin, Texas segment includes properties in the City of Austin, Texas. The Other segment includes properties located in Camden County in New Jersey and properties in New Castle County in Delaware. In addition to the five segments, the corporate group is responsible for cash and investment management, development of certain real estate properties during the construction period, and certain other general support functions. Land held for development and construction in progress is transferred to operating properties by region upon completion of the associated construction or project.

The following tables provide selected asset information and results of operations of the Company's reportable segments (in thousands):

Real estate investments, at cost:
	September 30, 2018		December 31, 2017
Philadelphia CBD	$	1,652,819	$	1,643,296
Pennsylvania Suburbs		979,068		958,796
Metropolitan Washington, D.C. (a)		539,105		978,257
Austin, Texas		170,912		163,653
Other		87,144		88,346
	$	3,429,048	$	3,832,348
Assets held for sale (a)		396,072		-
Operating properties	$	3,825,120	$	3,832,348

Corporate
Construction-in-progress	$	157,075	$	121,188
Land held for development (b)	$	77,578	$	98,242
Prepaid leasehold interests in land held for development, net (c)	$	40,100	$	-

	Three-month periods ended
	September 30,
	2018								2017
	Total revenue		Operating expenses (a)			Net operating income (loss)			Total revenue		Operating expenses (a)			Net operating income
Philadelphia CBD	$	64,352	$	(24,427	)	$	39,925		$	56,452	$	(22,010	)	$	34,442
Pennsylvania Suburbs		34,745		(11,937	)		22,808			34,861		(11,846	)		23,015
Metropolitan Washington, D.C.		22,754		(8,548	)		14,206			23,079		(8,500	)		14,579
Austin, Texas		8,641		(3,894	)		4,747			7,886		(3,929	)		3,957
Other		3,707		(2,436	)		1,271			3,752		(2,647	)		1,105
Corporate		799		(1,636	)		(837	)		2,408		(1,769	)		639
Operating properties	$	134,998	$	(52,878	)	$	82,120		$	128,438	$	(50,701	)	$	77,737

	Nine-month periods ended
	September 30,
	2018								2017
	Total revenue		Operating expenses (a)			Net operating income (loss)			Total revenue		Operating expenses (a)			Net operating income
Philadelphia CBD	$	190,478	$	(73,559	)	$	116,919		$	165,352	$	(64,311	)	$	101,041
Pennsylvania Suburbs		103,960		(37,018	)		66,942			105,673		(35,670	)		70,003
Metropolitan Washington, D.C.		69,012		(25,699	)		43,313			69,190		(26,347	)		42,843
Austin, Texas		25,474		(10,812	)		14,662			25,772		(11,634	)		14,138
Other		13,187		(9,601	)		3,586			14,274		(9,083	)		5,191
Corporate		3,031		(5,240	)		(2,209	)		6,888		(5,355	)		1,533
Operating properties	$	405,142	$	(161,929	)	$	243,213		$	387,149	$	(152,400	)	$	234,749

(a) Includes property operating expenses, real estate taxes and third party management expense.

Unconsolidated real estate ventures (in thousands):
	Investment in real estate ventures, at equity				Equity in income (loss) of real estate venture
	As of				Three-month periods ended September 30,						Nine-month periods ended September 30,
	September 30, 2018		December 31, 2017		2018			2017			2018			2017
Philadelphia CBD	$	20,544	$	39,939	$	(36	)	$	134		$	(183	)	$	113
Pennsylvania Suburbs		-		3,503		-			24			-			448
Metropolitan Washington, D.C.		119,032		119,817		(31	)		(5,264	)		(431	)		(4,872	)
Austin, Texas		14,411		13,973		423			(15	)		1,156			1,266
MAP Venture (a)		11,939		15,450		(444	)		(706	)		(2,011	)		(2,610	)
Other		1,856		1,939		89			104			287			268
Total	$	167,782	$	194,621	$	1		$	(5,723	)	$	(1,182	)	$	(5,387	)

Net operating income (“NOI”) is a non-GAAP financial measure defined as total revenue less property operating expenses, real estate taxes and third party management expenses. Property operating expenses that are included in determining NOI consist of costs that are necessary and allocable to our operating properties such as utilities, property-level salaries, repairs and maintenance, property insurance, management fees and bad debt expense. General and administrative expenses that are not reflected in NOI primarily consist of corporate-level salaries, amortization of share awards and professional fees that are incurred as part of corporate office management. All companies may not calculate NOI in the same manner. NOI is the measure that is used by the Company’s management to evaluate the operating performance of the Company’s real estate assets by segment. The Company believes NOI provides useful information to investors regarding the financial condition and results of operations because it reflects only those income and expense items that are incurred at the property level. While NOI is a relevant and widely used measure of operating performance of real estate investment trusts, it does not represent cash flow from operations or net income as defined by GAAP and should not be considered as an alternative to those measures in evaluating our liquidity or operating performance. NOI does not reflect interest expenses, real estate impairment losses, depreciation and amortization costs, capital expenditures and leasing costs. The Company believes that net income (loss), as defined by GAAP, is the most appropriate earnings measure. The following is a reconciliation of consolidated net income, as defined by GAAP, to consolidated NOI, (in thousands):

	Three-month periods ended September 30,					Nine-month periods ended September 30,
	2018			2017		2018			2017

Net income (loss)	$	(43,262	)	$	19,046	$	14,579		$	48,015
Plus:
Interest expense		19,257			19,732		58,091			61,473
Interest expense - amortization of deferred financing costs		618			577		1,872			1,807
Depreciation and amortization		43,900			42,429		130,908			132,584
General and administrative expenses		5,963			5,813		22,209			21,797
Equity in (income) loss of Real Estate Ventures		(1	)		5,723		1,182			5,387
Provision for impairment		56,865			-		56,865			3,057

Less:
Interest income		1,220			79		2,564			635
Income tax (provision) benefit		-			793		(158	)		1,032
Net gain (loss) on disposition of real estate		-			-		(35	)		8,411
Net gain on sale of undepreciated real estate		-			953		2,859			953
Net gain on Real Estate Venture transactions		-			13,758		37,263			28,340
Consolidated net operating income	$	82,120		$	77,737	$	243,213		$	234,749