Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2015

Accounting Policies [Abstract]

Schedule of changes in the allowance for doubtful accounts

Changes in the allowance for doubtful accounts are as follows (in thousands):

	Year ended December 31,
	2015			2014			2013
Balance, beginning of year	$	847		$	872		$	714
Charged to provision for doubtful accounts	1,132			481			570
Write-offs	(790		)	(506		)	(412		)
Balance, end of year	$	1,189		$	847		$	872

Schedule of depreciation or amortization of property and equipment

Depreciation or amortization of property and equipment, including assets held under capital leases, is calculated using the straight-line method over the asset’s estimated useful life as follows:

Buildings and leasehold improvements	2-30 years
Machinery, equipment, and rental tools	7-10 years
Furniture and fixtures	3 years
Transportation equipment	2-5 years
Computer equipment and software	3-7 years