Summary of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2017

Property and equipment are stated at cost. Depreciation is calculated using the straight-line method over estimated useful lives as follows:



	Useful Lives
Aircraft and components	10 to 20 years
Buildings	39 years
Building improvements	7 to 15 years
Computer equipment	2 to 6 years
Demonstration units	3 years
Furniture and office equipment	2 to 6 years
Leasehold improvements	Lesser of useful life or term of lease
Machinery and equipment	5 to 7 years
Tooling	3 years
Vehicles	5 years

Property and equipment, net, consists of the following (in thousands):



	September 30, 2017			December 31, 2016
Building and building improvements	$	86,023		$	85,966
Machinery and equipment	45,718			41,683
Aircraft and vehicles	25,329			45
Land	23,762			23,762
Leasehold improvements	15,015			8,289
Computer equipment	14,440			13,549
Tooling	13,667			12,895
Furniture and office equipment	10,821			9,669
Demonstration units	489			448
Construction-in-progress	8,434			7,923
Total property and equipment	243,698			204,229
Accumulated depreciation and amortization	(79,119		)	(68,233		)
Property and equipment, net	$	164,579		$	135,996

Changes in the product warranty accrual were as follows (in thousands):



	Nine Months Ended
	September 30, 2017			October 1, 2016
Warranty accrual, beginning of period	$	910		$	1,222
Accrual for warranties issued	712			722
Changes to pre-existing warranties (including changes in estimates)	(116		)	99
Settlements made	(486		)	(751		)
Warranty accrual, end of period	$	1,020		$	1,292

The change in accumulated other comprehensive loss was as follows (in thousands):



	Nine Months Ended September 30, 2017
Accumulated other comprehensive loss, beginning of period	$	(7,027	)
Unrealized gains from foreign currency translation	4,270
Accumulated other comprehensive loss, end of period	$	(2,757	)

reconciliation of basic and diluted net income per share is as follows (in thousands, except per share amounts):



	Three Months Ended				Nine Months Ended
	September 30, 2017		October 1, 2016		September 30, 2017		October 1, 2016
Net income	$	39,235	$	27,773	$	131,248	$	85,373
Basic net income per share:
Weighted-average shares outstanding - basic	52,079		49,477		51,469		49,386
Net income per basic share	$	0.75	$	0.56	$	2.55	$	1.73
Diluted net income per share:
Weighted-average shares outstanding - basic	52,079		49,477		51,469		49,386
Diluted share equivalent: stock options and RSUs	4,084		4,088		4,498		3,451
Weighted-average shares outstanding - diluted	56,163		53,565		55,967		52,837
Net income per diluted share	$	0.70	$	0.52	$	2.35	$	1.62

Supplemental cash flow information includes the following (in thousands):



	Nine Months Ended
	September 30, 2017		October 1, 2016
Cash paid during the year for:
Interest (net of amounts capitalized)	$	432	$	2,603
Income taxes	86,759		25,753
Noncash investing and financing activities:
Unpaid purchases of property, plant and equipment	$	3,349	$	1,232
Unsettled common stock proceeds from option exercises	113		476
Unsettled stock repurchases	2,653		—