8. Share-Based Compensation

The Company recognizes compensation expense based on estimated grant date fair values for all share-based awards issued to employees and directors, including stock options, restricted stock units and performance share units. The total compensation expense related to all share-based compensation plans was $3.5 million for both the three months ended March 31, 2016 and 2015.

Stock Options

There were no options granted during the three months ended March 31, 2016 or 2015.

Stock option awards as of December 31, 2015 and March 31, 2016, and changes during the three months ended March 31, 2016, were as follows:

						Weighted
						Average
				Weighted		Remaining		Aggregate
				Average		Contractual		Intrinsic
	Shares Under Option			Exercise		Term		Value
	(thousands)			Price		(years)		(millions)
Outstanding at December 31, 2015		3,707		$	19.66		3.6	$	8.4
Exercised		(22	)		13.23
Cancelled/forfeited/expired		(1	)		13.23
Outstanding at March 31, 2016		3,684			19.70		3.4		11.3
Vested and expected to vest at March 31, 2016		3,684			19.70		3.4		11.3
Exercisable at March 31, 2016		1,720		$	9.84		4.3	$	11.3

The aggregate intrinsic value in the table above represents the total pre-tax intrinsic value (the difference between the Company’s closing stock price on March 31, 2016 and December 31, 2015, respectively, and the exercise price, multiplied by the number of in-the-money options) that would have been received by the option holders had all option holders exercised their in-the-money options on March 31, 2016 and December 31, 2015. This amount will change in future periods based on the fair market value of the Company’s stock and the number of options outstanding. Total intrinsic value of options exercised for the three months ended March 31, 2016 and 2015 was $0.1 million and $0.5 million, respectively. There were no excess tax benefits on stock option exercises for the three months ended March 31, 2016. Excess tax benefits on stock option exercises, shown as financing cash inflows in the Condensed Consolidated Statements of Cash Flows, were $0.1 million for the three months ended March 31, 2015.

Compensation expense related to stock options for the three months ended March 31, 2016 and 2015 was $0.1 million and $0.2 million, respectively. As of March 31, 2016, all stock options are fully vested and there is no remaining unrecognized compensation expense.

Restricted Stock Units

Nonvested restricted stock unit awards as of December 31, 2015 and March 31, 2016, and changes during the three months ended March 31, 2016, were as follows:

	Shares			Grant Date
	(Thousands)			Fair Value
Nonvested at December 31, 2015		1,670		$	13.72
Granted		1,257			12.88
Vested		(570	)		11.40
Nonvested at March 31, 2016		2,357		$	13.82

Compensation expense related to restricted stock units for the three months ended March 31, 2016 and 2015 was $2.3 million and $2.6 million, respectively. As of March 31, 2016, there was $26.2 million of unrecognized share-based compensation expense related to approximately 2.3 million of restricted stock unit awards, with a weighted average grant date fair market value of $13.83, that are expected to vest over a weighted average period of 2.5 years. The fair value of these awards was determined based on the Company’s stock price on the grant date reduced by the present value of expected dividends through the vesting period.

Excess tax benefits on restricted stock units that vested, shown as financing cash inflows in the Condensed Consolidated Statements of Cash Flows, were $0.9 million and $2.1 million for the three months ended March 31, 2016 and 2015, respectively.

Performance Share Units

There were no grants or changes to nonvested performance share unit awards during the three months ended March 31, 2016.

Distributions under performance share unit awards are payable at the end of the performance period in common stock or cash, at the Company’s discretion. The fair value of these awards was determined based on the Company’s stock price on the grant date reduced by the present value of expected dividends through the vesting period. These awards are subject to forfeiture upon termination of employment prior to vesting, subject in some cases to early vesting upon specified events, including death, permanent disability or retirement of the grantee or a change in control of the Company. If the proposed spinoff transactions are completed, the terms of the performance share unit awards may be modified. Refer to Note 1, Basis of Presentation, for further details regarding the proposed spinoff transactions.

Compensation expense for the performance share unit awards granted in 2015 and 2014 is being recognized based on 100% estimated payout of 418,000 and 319,000 shares, for each respective period. Compensation expense related to performance share unit awards for the three months ended March 31, 2016 and 2015 was $1.1 million and $0.7 million, respectively. As of March 31, 2016, there was $5.7 million of unrecognized compensation expense related to performance share unit awards, which is expected to be recognized over a weighted average period of 1.5 years.