6. Share-Based Compensation

The Company has various stock plans under which employees and directors may be granted non-vested stock which vests over a specific time period. The 2007 Stock Plan, which expired April 26, 2017, allowed for the granting of non-vested stock in the form of restricted stock, restricted stock units, non-qualified stock options or incentive stock options, and stock appreciation rights. In April 2017, the Company’s 2017 Stock Plan was approved, which authorized 1.8 million shares to be granted as non-vested stock in the form of restricted stock, restricted stock units, non-qualified stock options or incentive stock options, and stock appreciation rights. As of December 31, 2018, there were 1.6 million shares available to be granted as non-vested stock under the Company’s existing stock plans.

Expense for shares of non-vested stock is recognized over the vesting period with a pro-rata vesting upon retirement. The vesting period is three years beginning with awards granted in December 2013. During the period of restriction, the holder of non-vested stock has voting rights and is entitled to receive all dividends and other distributions paid with respect to the stock.

The grants issued after December 2013, to elected officers, consist of 100% performance stock unit awards which are based on a three-year performance and vesting period and a pro-rata vesting upon retirement. Three-year performance that exceeds the stated performance metrics would result in an award up to 150% of the original grant. The holders of the performance stock units are not entitled to vote or receive dividends and other distributions paid with respect to the stock, until the units have vested and the shares of stock are issued.

The Company expenses awards for non-vested stock, including time-vesting stock and performance stock units, based on the fair value of the Company’s common stock at the date of the grant.

The following table summarizes the non-vested stock and performance stock unit activity:

(In thousands except fair value)	Shares			Grant Date Weighted Average Fair Value		Aggregate Intrinsic Value
Outstanding at December 31, 2015		542		$	48.94	$	34,063
Granted		119			69.92
Vested		(172	)		43.42
Cancelled		(54	)		52.41
Outstanding at December 31, 2016		435			56.44		34,184
Granted		115			74.26
Vested		(114	)		39.75
Cancelled		(24	)		63.62
Outstanding at December 31, 2017		412			65.64		30,113
Granted		142			59.45
Vested		(111	)		56.91
Cancelled		(63	)		64.71
Outstanding at December 31, 2018		380		$	66.02	$	21,239

The total intrinsic values of shares vested during 2018, 2017, and 2016, was $7.7 million, $8.8 million, and $12.8 million, respectively.

As of December 31, 2018, total remaining unearned compensation, net of expected forfeitures, related to non-vested stock and performance stock units was $12.5 million, which will be amortized over the weighted average remaining service period of 1.48 years.

Total pre-tax share-based compensation recognized in the Consolidated Statements of Earnings was $0.5 million, $5.9 million, and $7.7 million in 2018, 2017, and 2016, respectively. Fluctuations in share-based compensation was primarily due to performance based executive stock compensation. Tax related (costs) benefits of ($0.3) million, $0.5 million, and $2.8 million were also recognized in 2018, 2017, and 2016, respectively. Cash received from the exercise of stock options was $0.1 million, $0.3 million, and $0.7 million for 2018, 2017, and 2016, respectively, and is reflected in cash flows from financing activities in the Consolidated Statements of Cash Flows.