Property and Equipment

Property and equipment at December 31, 2018 and 2017 was comprised of the following (in thousands):



	December 31, 2018			December 31, 2017
Computers and equipment	$	27,519		$	22,702
Software and software development costs	144,260			120,278
Furniture and fixtures	8,123			7,754
Leasehold improvements	28,883			25,097
Property and equipment, gross	208,785			175,831
Less: accumulated depreciation and amortization	(131,865		)	(107,089		)
Property and equipment, net	$	76,920		$	68,742

During the years ended December 31, 2018, 2017 and 2016, the Company capitalized software development costs of $21.9 million, $20.5 million, and $14.8 million, respectively. Amortization expense related to capitalized software development costs was $16.0 million, $12.1 million and $15.2 million for 2018, 2017 and 2016, respectively. These costs are included in amortization and impairment expense in the accompanying consolidated statements of income. At December 31, 2018, the unamortized capitalized software development costs included in property and equipment in the accompanying consolidated balance sheets was $40.3 million.

Total depreciation expense plus amortization of software and internally developed software for the years ended December 31, 2018, 2017 and 2016 was $30.0 million, $23.5 million, and $23.9 million, respectively.

As of December 31, 2018 and 2017, property and equipment acquired under capital lease obligations was $1.2 million and $1.7 million, respectively, and was classified as computers and equipment. Accumulated depreciation for assets acquired under capital lease obligations was $0.8 million and $1.1 million as of December 31, 2018 and 2017.

In 2016, the Company re-assessed the fair value of KP Connector which is an internal use software developed by the Company based on the specifications outlined in a client agreement. In the second quarter of 2016, the client notified the Company that it no longer required the services provided by the Company. Accordingly, the Company determined that KP Connector’s carrying value was considered unrecoverable as of June 30, 2016, and recorded a $3.7 million impairment charge to amortization and impairment expense in the consolidated statements of income and a corresponding reduction of property and equipment, net, in the consolidated balance sheets.