Stock-based compensation

6 Months Ended

Jun. 30, 2018

Share-based Compensation [Abstract]

Stock-based compensation

Stock-based compensation

The Company recognizes compensation expense for all share-based payments granted based on the grant-date fair value estimated in accordance with the provisions of the FASB ASC 718-10. Compensation expense is recognized on a straight-line basis over the options’ or other awards’ estimated lives for fixed awards with ratable vesting provisions.

The Company granted 4 restricted stock units ("RSUs") at a weighted average grant-date fair value of $204.35 per unit for the three months ended June 30, 2018. The Company granted 127 RSUs at a weighted average grant-date fair value of $237.94 per unit for the six months endedJune 30, 2018. The Company granted 153 RSUs at a weighted average grant-date fair value of $226.85 per unit for the six months endedJuly 1, 2017. The Company recognized stock-based compensation costs related to the issuance of RSUs of $13,645 ($10,097 net of taxes) and $13,875 ($8,419 net of taxes) for the three months endedJune 30, 2018 and July 1, 2017, respectively, which has been allocated to cost of sales and selling, general and administrative expenses. The Company recognized stock-based compensation costs related to the issuance of RSUs of $21,593 ($15,979 net of taxes) and $23,424 ($14,214 net of taxes) for the six months endedJune 30, 2018 and July 1, 2017, respectively, which has been allocated to cost of sales and selling, general and administrative expenses. Pre-tax unrecognized compensation expense for unvested RSUs granted to employees, net of estimated forfeitures, was $32,114 as of June 30, 2018, and will be recognized as expense over a weighted-average period of approximately 1.60 years. The Company also recognized stock-based compensation costs related to stock options of $6 ($4 net of taxes) for the six months endedJuly 1, 2017 which was allocated to cost of sales and selling, general and administrative expenses.