Liabilities (Tables)

3 Months Ended

Mar. 31, 2017

Liabilities

Schedule of accrued expenses and other current liabilities

	March 31,		December 31,
	2017		2016
	(in thousands)
Payroll and related benefits	$	13,538	$	18,780
Warranty	4,209		4,217
Professional fees	2,806		1,827
Installation	1,411		1,382
Sales, use, and other taxes	436		1,282
Restructuring liability	1,219		1,796
Interest	1,915		—
Other	2,946		3,917
Total	$	28,480	$	33,201

Schedule of changes in product warranty reserves

	(in thousands)
Balance - December 31, 2016	$	4,217
Warranties issued	973
Consumption of reserves	(1,327		)
Changes in estimate	346
Balance - March 31, 2017	$	4,209

Schedule of restructuring accrual activities

	Personnel
	Severance and			Facility
	Related Costs			Related Costs			Total
	(in thousands)
Balance - December 31, 2016	$	1,796		$	—		$	1,796
Provision	661			677			1,338
Payments	(1,238		)	(677		)	(1,915		)
Balance - March 31, 2017	$	1,219		$	—		$	1,219

Schedule of carrying value of Convertible Senior Notes

	March 31,
	2017
	(in thousands)
Principal amount	$	345,000
Unamortized debt discount	(70,527		)
Unamortized transaction costs	(7,104		)
Net carrying value	$	267,369

Summary of interest expense related to Convertible Senior Notes

	Three months ended March 31,
	2017
	(in thousands)
Cash Interest Expense
Coupon interest expense	$	1,915
Non-Cash Interest Expense
Amortization of debt discount	1,985
Amortization of transaction costs	200
Total Interest Expense	$	4,100