Details of Selected Balance Sheet Accounts (Tables)

6 Months Ended

Jun. 30, 2019

Balance Sheet Related Disclosures [Abstract]

Schedule of Accounts Receivable

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

Schedule of Inventories

	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

Property, Plant and Equipment

	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

Schedule of Accrued Liabilities

	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