The following table summarizes the status of the Company’s performance-based restricted stock: As of December 31, 2020, there was $4.4 million of unrecognized stock-based compensation related to nonvested performance-based restricted stock that is expected to be recognized over an estimated weighted-average amortization period of fourteen months. At December 31, 2020, the intrinsic value of the performance-based restricted stock outstanding was $26.6 million and the intrinsic value of the performance-based restricted stock expected to vest was $21.5 million. The weighted average grant date fair values for performance-based restricted stock granted in 2019 and 2018 was $37.27 and $26.36, respectively. Restricted Stock Units, performance-based Company metrics:  As of December 31, 2020, a total of 0.4 million shares of performance-based restricted stock units were outstanding. The performance-based restricted stock units vest if the Company meets various operations and earnings targets set by the Organization & Compensation Committee of the Board of Directors. The fair value was based on the closing market price of the Company’s common stock on the date of award and is being amortized over the estimated service period to achieve the operations and earnings targets. The following table summarizes the status of the Company’s performance-based restricted stock units: As of December 31, 2020, there was $6.2 million of unrecognized stock-based compensation related to nonvested performance-based restricted stock units that are expected to be recognized over an estimated weighted-average amortization period of twenty-six months. At December 31, 2020, the intrinsic value of the performance-based restricted stock units outstanding was $19.7 million and the intrinsic value of the performance-based restricted stock expected to vest was $9.8 million. Employee Stock Purchase Plan:  The ESPP enables eligible employees the opportunity to purchase the Company’s common stock at a price not less than 85% of the fair market value of the common stock on the last day of the respective offering period. A maximum of 1.5 million shares are authorized for issuance. During 2020, 0.2 million shares were issued under the ESPP at an average price of $45.65. During 2019, 0.1 million shares were issued under the ESPP at an average price of $45.25. During 2018, 0.1 million shares were issued under the ESPP at an average price of $32.11. Stock Options:  As of December 31, 2020, there were no stock options outstanding. The following table summarizes the status of the Company’s stock options: The total intrinsic value for options exercised in 2020, 2019, and 2018 was $11.0 million, $0.8 million, and $0.9 million, respectively. The fair value of the stock option grant in 2019 was estimated using a Black-Scholes model with an expected life of seven years, volatility of 33.48%, and a risk-free rate of 2.62%. The Company did not grant stock options in 2020 and 2018. Performance Common Shares : In February 2018, the Company granted senior executives 0.1 million performance common shares that vest according to the attainment of share prices ranging from $34.00 per share to $42.00 per share of the Company's stock. The performance common shares were valued at a weighted average price of $18.67 using a Monte Carlo model. The Company recognized the grant-date fair value of these awards as stock-based compensation expense ratably over 75 Performance Based Restricted Stock (In millions) Weighted Average Grant Date Fair Value Outstanding at December 31, 2019 1.0  $ 29.41  Exercised (0.4) 25.01  Canceled (0.1) 29.00  Outstanding at December 31, 2020 0.5  $ 36.59  Expected to vest at December 31, 2020 0.4  $ 35.52  Performance Based Restricted Stock Units (In millions) Weighted Average Grant Date Fair Value Outstanding at December 31, 2019 —  $ —  Granted 0.4  50.00  Outstanding at December 31, 2020 0.4  $ 50.00  Expected to vest at December 31, 2020 0.2  $ 50.00  Stock Options (In millions)  Weighted Average Exercise Price  Outstanding at December 31, 2019 0.4  $ 23.11  Exercised and Cancelled (0.4) 23.11  Outstanding at December 31, 2020 —  $ — 