Debt (Tables)

9 Months Ended

Sep. 29, 2018

Debt

Summary of information about the equity and liability components of the convertible senior notes

The carrying amount of the Notes consisted of the following (in thousands):

	September 29, 2018			December 30, 2017
Liability component
Principal	$	400,000		$	400,000
Unamortized debt discount	(42,178		)	(50,499		)
Unamortized debt issuance costs	(6,365		)	(7,622		)
Net carrying amount	$	351,457		$	341,879
Equity component
Net carrying amount	$	57,735		$	57,735

Schedule of components of interest expense

Interest expense related to the Notes was comprised of the following (in thousands):

	Three Months Ended				Nine Months Ended
	September 29, 2018		September 30, 2017		September 29, 2018		September 30, 2017
Contractual interest expense	$	1,360	$	1,360	$	4,125	$	3,117
Amortization of debt discount	2,801		2,674		8,322		6,068
Amortization of debt issuance costs	423		404		1,256		916
	$	4,584	$	4,438	$	13,703	$	10,101