During 2018, the Company determined that GPT met the held for sale criteria and recognized $2,190 in impairment loss.

During 2019, the Company continued to assess the fair value of its GPT disposal group, less costs to sell, at each reporting period. As a result of these fair value measurements, the Company recorded additional impairment losses of $9,885 and $16,883 for the three- and six-month periods ended June 30, 2019, respectively. Additionally, during the first quarter of 2019, the Company determined that an equity investment met the held for sale criteria and recognized impairment losses of $1,000 and $4,486 for the three- and six-month periods ended June 30, 2019, respectively.

See note 2 for information about the Company’s held for sale accounting policy, including a description of the criteria necessary for a disposal group to qualify for classification as held for sale. GPT did not meet the criteria to be classified as a discontinued operation.

The assets and liabilities of the disposal group classified as held for sale as of June 30, 2019 are as follows:

Accounts receivable, net	$	1,808
Inventory, net		5,499
Prepaid expenses and other assets		268
Operating lease right-of-use assets		4,118
Investment		—
Property and equipment, net		7,440
Other intangible assets, net		1,082
Deferred income tax assets		4,572
Impairment loss		(18,073	)
Total assets held for sale	$	6,714

Accounts payable	$	405
Accrued liabilities		2,192
Operating lease liabilities		4,117
Total liabilities held for sale	$	6,714

The equity investment described above, does not have a readily determinable fair value and is measured at cost, less impairments, adjusted for observable price changes in orderly transactions for identical or similar investments of the same issuer.

The fair value of the GPT disposal group was measured based on observable inputs other than Level 1 prices.

Management’s estimates used to record impairment expense are inherently uncertain and may change in future periods.