Property, net:

Property, net consists of the following:



	June 30, 2018			December 31, 2017
Land	$	1,518,161		$	1,567,152
Buildings and improvements	6,099,577			6,385,035
Tenant improvements	616,150			620,352
Equipment and furnishings	190,031			187,998
Construction in progress	437,386			366,996
	8,861,305			9,127,533
Less accumulated depreciation	(1,992,461		)	(2,018,303		)
	$	6,868,844		$	7,109,230

Depreciation expense was $66,850 and $69,364 for the three months ended June 30, 2018 and 2017, respectively, and $134,794 and $138,320 for the six months ended June 30, 2018 and 2017, respectively.

The (loss) gain on sale or write down of assets, net was $(9,518) and $(477) for the three months ended June 30, 2018 and 2017, respectively, and $(47,030) and $49,088 for the six months ended June 30, 2018 and 2017, respectively.

The (loss) gain on sale or write down of assets, net for the three and six months ended June 30, 2018 includes impairment losses of $7,494 on two freestanding stores and $1,660 on Southridge Center. In addition, the (loss) gain on sale or write down of assets, net for the six months ended June 30, 2018 includes impairment losses of $36,338 on SouthPark Mall and $1,043 on Promenade at Casa Grande. The impairment losses were due to the reduction of the estimated holding period of the properties.

The (loss) gain on sale or write down of assets, net for three and six months ended June 30, 2018 includes a loss of $311 on the sale of Promenade at Casa Grande (See Note 15—Dispositions). In addition, the (loss) gain on sale or write down of assets, net for the six months ended June 30, 2017 includes a gain of $59,713 on the sale of Cascade Mall and Northgate Mall (See Note 15—Dispositions) offset in part by a loss of $10,138 on the write down of an investment in non-real estate assets.

The following table summarizes certain of the Company's assets that were measured on a nonrecurring basis as a result of impairment losses recorded for the three and six months ended June 30, 2018 as described above:



	Total Fair Value Measurement		Quoted Prices in Active Markets for Identical Assets		Significant Other Unobservable Inputs		Significant Unobservable Inputs
	Total Fair Value Measurement		(Level 1)		(Level 2)		(Level 3)
June 30, 2018	$	72,700	$	—	$	72,700	$	—

The fair values relating to the impairments were based on sales contracts.