Fixed Assets

As of December 31, 2018 and 2017, fixed assets consisted of the following:



	As of December 31,
	2018			2017
	(dollars in thousands)
Telephone and computer equipment	$	3,301		$	3,465
Computer software	4,214			2,914
Furniture and fixtures	2,829			1,423
Leasehold improvements	37,652			36,702
Assets acquired under capital leases—equipment	10,077			6,920
Aircraft and related equipment	—			17,369
Other	—			58
	58,073			68,851
Less: Accumulated depreciation and amortization	(31,630		)	(28,355		)
	$	26,443		$	40,496

Depreciation and amortization expense related to fixed assets was $7.4 million, $7.0 million and $7.7 million for the years ended December 31, 2018, 2017, and 2016, respectively and are included in depreciation and amortization expense in the accompanying consolidated statements of operations.

On April 22, 2016, the Company entered into a transaction whereby the Company acquired a portfolio of four specialized aircraft which were on lease. During the year ended December 31, 2016, the Company purchased two aircraft and entered into two additional lease agreements. As of December 31, 2017, aircraft and related equipment of $17.4 million was held for leasing purposes. All of the remaining five planes were sold during the fourth quarter of 2018 for a loss of $1.0 million, which is included in other expenses in the accompanying consolidated statement of operations. One of the planes were sold during the third quarter of 2017 for a gain of $2.3 million. Depreciation expense related to leased assets was $0.8 million, $1.5 million and $1.7 million for the years ended December 31, 2018, 2017, and 2016, respectively.

Assets acquired under capital leases were $10.1 million and $6.9 million as of December 31, 2018 and 2017, respectively. If the assets acquired under capital leases transfer title at the end of the lease term or contain a bargain purchase option, the assets are amortized over their estimated useful lives; otherwise, the assets are amortized over the respective lease term. The depreciation of assets capitalized under capital leases is included in depreciation and amortization expenses and was $1.6 million, $1.0 million, and $1.2 million for the years ended December 31, 2018, 2017, and 2016, respectively. As of December 31, 2018 and 2017, accumulated depreciation related to assets acquired under capital leases was $5.0 million and $3.4 million respectively.