17.    STOCK-BASED COMPENSATION

Stock Compensation Plans

Time Lapse Restricted Shares and Restricted Stock Units

Time lapse restricted shares (TLRSs) have been issued to officers and other management employees under the Company’s Employee Stock Incentive Plan. The Company recognizes compensation expense for the unvested portion of awards outstanding over the remainder of the service period. The compensation cost recorded for these awards is based on their closing stock price at the grant date less the cost of estimated forfeitures. Forfeitures are estimated at the time of grant and revised, if necessary, in subsequent periods to reflect actual forfeitures. Cash flows related to share-based payment awards to employees that result in tax benefits in excess of recognized cumulative compensation cost (excess tax benefits) are classified as a financing activity in the accompanying consolidated statements of cash flows.

TLRSs provide for the issuance of a share of the Company’s Common Stock at no cost to the holder and generally vest after a certain stipulated number of years from the grant date, depending on the terms of the issue. TLRSs vest in 20 percent increments starting with the second anniversary of the grant, over six years from the date of grant. During these years, grantees receive all dividends declared and retain voting rights for the granted shares. The agreements under which the restricted stock is issued provide that shares awarded may not be sold or otherwise transferred until restrictions established under the plans have lapsed.

In April 2018, the Company granted a one-time issuance of TLRSs on a tiered Company tenure basis to U.S. based employees. The one-time grant vests 100 percent on the first anniversary date of the granted shares. The total shares granted were less than 0.1 million shares. During the year, grantees receive all dividends declared and retain voting rights for the granted shares. The agreements under which the one-time restricted stock is issued provide that shares awarded may not be sold or otherwise transferred until restrictions established under the plans have lapsed.

All share and per share information has been adjusted for the three-for-two stock split effective December 10, 2018.

The Company issued time lapse restricted shares of 0.6, 0.7, and 0.8 million for the years ended December 31, 2018, 2017, and 2016, respectively.

The Company issues new shares from its authorized but unissued share pool. At December 31, 2018, approximately 5.9 million shares of the Company’s common stock were reserved for issuance. In accordance with the FASB ASC Topic 718, “Compensation – Stock Compensation,” the Company recognizes the fair value of the award on a straight line basis over the service periods of each award. The Company estimates restricted share forfeiture rates based on its historical experience.

The following table summarizes the components of the Company’s stock-based compensation programs recorded as expense ($ in thousands):

As of December 31, 2018 and 2017, $39.2 million and $32.9 million, respectively, of total unrecognized compensation cost related to time-lapse restricted shares are expected to be recognized over a weighted average period of approximately 4.1 years and 3.9 years at December 31, 2018 and December 31, 2017, respectively.

The following table summarizes information on unvested restricted stock units outstanding as of December 31, 2018, 2017 and 2016: