the fair value of options that vested during the years ended december 31 , 2017 , 2016 and 2015 was $ 6.8 million , $ 6.0 million and $ 7.8 million , respectively . the intrinsic value of fortune brands stock options exercised in the years ended december 31 , 2017 , 2016 and 2015 was $ 70.6 million , $ 88.1 million and $ 78.0 million , respectively . performance awards performance share awards were granted to officers and certain employees of the company under the plans and represent the right to earn shares of company common stock based on the achievement of or company-wide performance conditions , including cumulative diluted earnings per share , average return on invested capital , average return on net tangible assets and ebitda during the three-year performance period . compensation cost is amortized into expense over the performance period , which is generally three years , and is based on the probability of meeting performance targets . the fair value of each performance share award is based on the average of the high and low stock price on the date of grant . the following table summarizes information about performance share awards as of december 31 , 2017 , as well as activity during the year then ended . the number of performance share awards granted are shown below at the target award amounts : number of performance share awards weighted-average grant-date fair value .
what was the percentage change in the weighted average fair value on the date of the award of the common stock
the remaining unrecognized pre-tax compensation cost related to performance share awards at december 31 , 2017 was approximately $ 6.8 million , and the weighted-average period of time over which this cost will be recognized is 1.3 years . the fair value of performance share awards that vested during 2017 was $ 5.6 million ( 100580 shares ) . director awards stock awards are used as part of the compensation provided to outside directors under the plan . awards are issued annually in the second quarter . in addition , outside directors can elect to have director fees paid in stock or can elect to defer payment of stock . compensation cost is expensed at the time of an award based on the fair value of a share at the date of the award . in 2017 , 2016 and 2015 , we awarded 15311 , 16471 and 19695 shares of company common stock to outside directors with a weighted average fair value on the date of the award of $ 63.43 , $ 57.37 and $ 46.21 , respectively . 14 . defined benefit plans we have a number of pension plans in the united states , covering many of the company 2019s employees , however these plans have been closed to new hires . the plans provide for payment of retirement benefits , mainly commencing between the ages of 55 and 65 . after meeting certain qualifications , an employee acquires a vested right to future benefits . the benefits payable under the plans are generally determined on the basis of an employee 2019s length of service and/or earnings . employer contributions to the plans are made , as necessary , to ensure legal funding requirements are satisfied . also , from time to time , we may make contributions in excess of the legal funding requirements . service cost for 2017 relates to benefit accruals in an hourly union defined benefit plan in our security segment . benefit accruals under all other defined benefit pension plans were frozen as of december 31 , 2016. .