4.	DETAILS OF SELECTED BALANCE SHEET ACCOUNTS

Additional information regarding selected balance sheet accounts at September 30, 2016 and December 31, 2015 is presented below (in thousands):

	September 30, 2016			December 31, 201 5
Accounts receivable, net:
Trade	$	47,600		$	44,650
Unbilled revenue		20,575			16,649
Other		1,059			1,289
Total accounts receivable		69,234			62,588
Allowance for doubtful accounts		(756	)		(1,121	)
Total accounts receivable, net	$	68,478		$	61,467

	September 30, 2016		December 31, 201 5
Inventories:
Finished goods and purchased products	$	1,911	$	1,854
Work in process		56		1,260
Raw materials		1,597		2,517
Total inventories	$	3,564	$	5,631

During the third quarter of 2016, we recorded a $0.9 million write-down of inventory at our modular construction and manufacturing plant in Canada, which is included in Cost of sales in our accompanying unaudited consolidated statements of operations.

	Estimated Useful Life (in years)			September 30, 2016			December 31, 201 5
Property, plant and equipment, net:
Land				$	43,085		$	47,825
Accommodations assets	3	-	15		1,592,789			1,482,842
Buildings and leasehold improvements	3	-	20		28,434			29,099
Machinery and equipment	4	-	15		9,672			9,183
Office furniture and equipment	3	-	7		30,953			29,172
Vehicles	3	-	5		15,379			15,412
Construction in progress					34,376			52,558
Total property, plant and equipment					1,754,688			1,666,091
Accumulated depreciation					(909,887	)		(734,177	)
Total property, plant and equipment, net				$	844,801		$	931,914

	September 30, 2016		December 31, 201 5
Accrued liabilities:
Accrued compensation	$	9,663	$	11,726
Accrued taxes, other than income taxes		4,631		963
Accrued interest		18		12
Other		1,849		2,133
Total accrued liabilities	$	16,161	$	14,834