Incentive Plans

Stock-based compensation

For the three and six months ended June 30, 2012, the Company recorded $21.7 million and $43.3 million, respectively, of stock-based compensation expense for all plans, as compared to $13.8 million and $26.4 million for the same respective periods of 2011. As of June 30, 2012, there was $156.0 million of unrecognized compensation expense related to unvested share- and unit-based compensation plan awards, including $27.0 million attributable to stock-based awards that are expected to be settled in cash on their vesting date, rather than in equity shares ("Liability Awards"). This compensation will be recognized over the remaining vesting periods of the awards, which is a period of less than three years on a weighted average basis. As of June 30, 2012 and December 31, 2011, accounts payable – due to affiliates includes $8.2 million and $9.2 million, respectively, of liabilities attributable to Liability Awards.

The Company's issued shares, as reflected in the consolidated balance sheets at June 30, 2012 and December 31, 2011, do not include 304,260 and 533,125 common shares, respectively, associated with unvested stock-based compensation awards that have voting rights.

The following table summarizes the activity that occurred during the six months ended June 30, 2012, for each type of share-based incentive award issued by Pioneer:



	Restricted Stock Equity Awards		Restricted Stock Liability Awards		Performance Units	Stock Options		Pioneer Southwest LTIP Restricted Units		Pioneer Southwest LTIP Phantom Units
Outstanding at December 31, 2011	1,857,612		322,925		114,128	564,044		7,492		65,157
Awards granted	897,591		223,375		47,875	98,819		7,496		37,487
Awards vested	(1,199,536	)	(115,700	)	—	—		(7,492	)	—
Options exercised	—		—		—	(64,509	)	—		—
Awards forfeited	(15,145	)	(10,342	)	—	—		—		—
Outstanding as of June 30, 2012	1,540,522		420,258		162,003	598,354		7,496		102,644

Postretirement Benefit Obligations

As of June 30, 2012 and December 31, 2011, the Company had $8.5 million and $7.5 million, respectively, of unfunded accumulated postretirement benefit obligations, the current and noncurrent portions of which are included in other current liabilities and other liabilities in the accompanying consolidated balance sheets. These obligations are comprised of five unfunded plans, of which four relate to predecessor entities that the Company acquired in prior years, and two funded plans that the Company assumed sponsorship for in conjunction with the acquisition of Premier Silica.

The unfunded plans had no assets as of June 30, 2012 or December 31, 2011. The Company's funding policy for the Premier Silica plans is to contribute amounts sufficient to meet legal funding requirements, plus any additional amounts that the Company may determine to be appropriate considering the funded status of the plan, tax deductibility, the cash flow generated by the Company, and other factors. The Company continually reassesses the amount and timing of any discretionary contributions and could elect to make such a contribution in 2012.