Details of Selected Balance Sheet Accounts

6 Months Ended

Jun. 30, 2019

DETAILS OF SELECTED BALANCE SHEET ACCOUNTS

Additional information regarding selected balance sheet accounts at June 30, 2019 and December 31, 2018 is presented below (in thousands):



	June 30, 2019			December 31, 2018
Accounts receivable, net:
Trade	$	66,886		$	48,875
Unbilled revenue	23,654			21,169
Other	449			555
Total accounts receivable	90,989			70,599
Allowance for doubtful accounts	(226		)	(376		)
Total accounts receivable, net	$	90,763		$	70,223



	June 30, 2019		December 31, 2018
Inventories:
Finished goods and purchased products	$	2,493	$	2,461
Work in process	832		945
Raw materials	1,096		907
Total inventories	$	4,421	$	4,313



	Estimated Useful Life (in years)			June 30, 2019			December 31, 2018
Property, plant and equipment, net:
Land				$	43,411		$	46,805
Accommodations assets	3	—	15	1,692,033			1,650,758
Buildings and leasehold improvements	7	—	20	25,935			25,168
Machinery and equipment	4	—	15	11,105			10,693
Office furniture and equipment	3	—	7	55,898			54,459
Vehicles	3	—	5	14,416			14,589
Construction in progress				21,864			7,119
Total property, plant and equipment				1,864,662			1,809,591
Accumulated depreciation				(1,228,624		)	(1,150,686		)
Total property, plant and equipment, net				$	636,038		$	658,905



	June 30, 2019		December 31, 2018
Accrued liabilities:
Accrued compensation	$	11,295	$	13,545
Accrued taxes, other than income taxes	2,434		2,177
Accrued interest	29		5
Other	933		229
Total accrued liabilities	$	14,691	$	15,956