Stock-Based Compensation

The Company’s stock-based compensation expense for the three and six months ended June 30, 2017 and 2016 included PRSUs, non-qualified stock options, restricted stock units ("RSUs") and deferred stock units ("DSUs"). A summary of the Company’s stock-based compensation expense is presented in the following table.



	Three Months Ended June 30,				Six Months Ended June 30,
(in millions)	2017		2016		2017			2016
PRSU expense (benefit)	$	1.2	$	1.7	$	(8.1	)	$	4.2
Option expense	1.8		1.1		3.8			2.8
RSU/DSU expense	3.0		1.7		6.9			3.6
Total stock-based compensation expense	$	6.0	$	4.5	$	2.6		$	10.6

During the six months ended June 30, 2017, the Company recorded a $9.3 million benefit in the Condensed Consolidated Statements of Income related to a change in estimate associated with performance-based stock compensation that is no longer probable of payout as a result of the termination of the Mattress Firm relationship.

The Company did not record any accelerated stock-based compensation expense during each of the three months ended June 30, 2017 and 2016. During the six months ended June 30, 2017 and 2016, the Company recorded $0.9 million and $2.0 million of accelerated stock-based compensation expense associated with executive management transition, respectively.

The Company has 1.2 million PRSUs outstanding that will vest if the Company achieves more than $650.0 million of adjusted earnings before interest, tax, depreciation and amortization ("Adjusted EBITDA") for 2017 (the "2017 Aspirational Plan PRSUs"). All of the 2017 Aspirational Plan PRSUs will vest in full if the Company achieves Adjusted EBITDA in 2017 greater than $650.0 million. In addition, if this target is not met in 2017 but the Company achieves more than $650.0 million in Adjusted EBITDA for 2018, then one-third of the total 2017 Aspirational Plan PRSUs will vest, and the remaining 2017 Aspirational Plan PRSUs will be forfeited. If the Company does not achieve more than $650.0 million of Adjusted EBITDA in either 2017 or 2018, then all of the 2017 Aspirational Plan PRSUs will be forfeited. Adjusted EBITDA is defined as the Company’s "Consolidated EBITDA" as such term is defined in the Company’s 2012 Credit Agreement.

The Company did not record any stock-based compensation expense related to the 2017 Aspirational Plan PRSUs during the three and six months ended June 30, 2017 and 2016, as it is not considered probable that the Company will achieve the specified performance target as of December 31, 2017 or December 31, 2018. The Company will continue to evaluate the probability of achieving the performance condition in future periods and record the appropriate expense if necessary. Based on the price of the Company’s common stock on the grant date, the total unrecognized compensation expense related to this award if the performance target is met for 2017 is $83.9 million, which would be expensed over the remaining service period if achievement of the performance condition becomes probable.