4. Property and equipment

The following is a summary of property and equipment, at cost less accumulated depreciation and amortization:

	March 31, 2018			December 31, 2017
Leasehold improvements	$	408,360		$	418,023
Software	44,575			42,281
Construction in progress	37,027			27,291
Computer equipment	12,332			13,245
Furniture, fixtures and office equipment	1,769			1,806

Total property and equipment	504,063			502,646
Less: accumulated depreciation and amortization	(239,434		)	(240,287		)

Total property and equipment, net	$	264,629		$	262,359

Depreciation and amortization expense, which includes depreciation and amortization for property and equipment under capital leases, is allocated as follows in the accompanying condensed consolidated statements of operations:

	Three Months Ended March 31,
	2018		2017
Network access	$	13,587	$	8,375
Network operations	4,256		4,155
Development and technology	2,508		2,195
General and administrative	255		260

Total depreciation and amortization of property and equipment	$	20,606	$	14,985