20. Incentive Compensation Plans

The following table summarizes the share-based compensation plans administered by the Compensation Committee of the Board ("Compensation Committee") that were active during the periods presented in the accompanying Consolidated Statements of Operations:

Share-based compensation plan	Award Classification	Further awards authorized for issuance under plan as of December 31, 2013	Awards outstanding under the plan as of December 31, 2013

2008 Long-Term Incentive Plan ("2008 LTIP")	Equity	Yes	Yes	N/A
Long-Term Incentive Plan ("2002 LTIP")	Liability	No	No	2011

Compensation Expense

Total compensation expense recorded for share-based pay arrangements was as follows (in thousands):

	Year ended December 31,

	2013		2012		2011
Phantom units	$	16,282	$	14,615	$	13,479
Distribution equivalent rights(1)		77		41		446


Total compensation expense	$	16,359	$	14,656	$	13,925

(1): A distribution equivalent right is a right, granted in tandem with a specific phantom unit, to receive an amount in cash equal to and at the same time as, the cash distributions made by the Partnership with respect to a unit during the period such phantom unit is outstanding. Payment of distribution equivalent rights associated with units that are expected to vest are recorded as capital distributions, however, payments associated with units that are not expected to vest are recorded as compensation expense.

Compensation expense under the share-based compensation plans has been recorded as either Selling, general and administrative expenses or Facility expenses in the accompanying Consolidated Statements of Operations.

As of December 31, 2013, total compensation expense not yet recognized related to the unvested awards under the 2008 LTIP was approximately $15.4 million, with a weighted average remaining vesting period of approximately 0.9 years.

2008 LTIP

The 2008 LTIP was approved by unitholders on February 21, 2008. The 2008 LTIP provides 3.7 million common units for issuance to the Corporation's employees and affiliates as share-based payment awards. The 2008 LTIP was created to attract and retain highly qualified officers, directors and other key individuals and to motivate them to serve the General Partner, the Partnership and their affiliates and to expend maximum effort to improve the business results and earnings of the Partnership and its affiliates. Awards authorized under the 2008 LTIP include unrestricted units, restricted units, phantom units, distribution equivalent rights and performance awards to be granted in any combination.

TSR Performance Units. In April 2010, the Board granted 282,000 TSR Performance Units under the 2008 LTIP to senior executives and other key employees. The TSR Performance Units are classified as equity awards and do not contain distribution equivalent rights. The TSR Performance Units vested in equal installments on January 31, 2011 and January 31, 2012, based on the Partnership's relative total unitholder return (unit price appreciation and distribution performance) over the three-year calendar period prior to the scheduled vesting date compared to the total unitholder return of a defined group of peer companies over the same period ("Market Criteria"). In January 2011 and 2012, 141,000 TSR Performance Units vested based on the Market Criteria and the Board exercised its discretion to issue and immediately vest an additional 35,250 units.

Compensation expense related to the TSR Performance Units that vested solely based on the Market Criteria was recognized over the requisite service period based on the fair value of the units as of the grant date. However, a grant date, as defined by GAAP, was not established for the TSR Performance Units that vest based on a combination of the Market Criteria and performance criteria until the Board exercised its discretion because the performance criteria prevents a mutual understanding of the key terms of the award. Therefore, compensation expense related to this portion of the TSR Performance Units was recognized over the requisite service period based on the fair value of the units as of each reporting date. The requisite service period for all TSR Performance Units began in April 2010 when the Board approved the awards. TSR Compensation expense recognized related to TSR Performance Units was approximately zero, $2.2 million and $4.8 million for the years ended December 31, 2013, 2012 and 2011, respectively.

The fair value of the TSR Performance Units was measured at each appropriate measurement date using a Monte Carlo simulation model that estimated the most likely outcome based on the terms of the award. The key inputs in the model include the market price of the Partnership's common units as of the valuation date, the historical volatility of the market price of the Partnership's common units, the historical volatility of the market price of the common units or common stock of the peer companies and the correlation between changes in the market price of the Partnership's common units and those of the peer companies.

Summary of Equity Awards

Awards under the 2008 LTIP qualify as equity awards. Accordingly, the fair value is measured at the grant date using the market price of the Partnership's common units. A phantom unit entitles an employee to receive a common unit upon vesting. The Partnership generally issues new common units upon vesting of phantom units. Phantom unit awards generally vest in equal tranches over a three-year period or cliff vest after three years. For service-based awards, compensation expense related to each tranche is recognized over its requisite service period, reduced for an estimate of expected forfeitures. Compensation expense related to performance-based awards is recognized when probability of vesting is established. As part of a net settlement option, employees may elect to surrender a certain number of phantom units and in exchange, the Partnership assumes the income tax withholding obligations related to the vesting. Phantom units surrendered for the payment of income tax withholdings will again become available for issuance under the plan from which the awards were initially granted, provided that further awards are authorized for issuance under the plan. The Partnership was required to pay approximately $5.2 million, $8.1 million and $6.0 million during the years ended December 31, 2013, 2012 and 2011, respectively, for income tax withholdings related to the vesting of equity awards. The Partnership received no proceeds from the issuance of phantom units and none of the phantom units that vested were redeemed by the Partnership for cash.

The following is a summary of all phantom unit activity under the 2008 LTIP for the year ended December 31, 2013:

			Weighted- average Grant-date Fair Value

Unvested at December 31, 2012	687,576		$	45.79
Granted	342,489			57.48
Vested	(260,113	)		38.78
Forfeited	(12,443	)		53.38


Unvested at December 31, 2013	757,509			53.36

The total fair value and intrinsic value of the phantom units vested under the 2008 LTIP was $10.1 million, $10.4 million and $10.7 million during the years ended December 31, 2013, 2012 and 2011, respectively. The total fair value and intrinsic value of the TSR Performance Units vested was zero, $6.5 million and $4.9 million during the years ended December 31, 2013, 2012 and 2011, respectively.

2002 LTIP

The phantom units awarded under the 2002 LTIP are classified as liability awards. Accordingly, the fair value of the outstanding awards is re-measured at the end of each reporting period using the market price of the Partnership's common units. The fair value of the phantom units awarded is amortized into earnings as compensation expense over the vesting period, which is generally three years. A phantom unit entitles an employee to receive a common unit upon vesting or at the discretion of the Compensation Committee, the cash equivalent to the value of a common unit. The Partnership generally issues new common units upon the vesting of phantom units. As part of a net settlement option, employees may elect to surrender a certain number of phantom units and in exchange, the Partnership assumes the income tax withholding obligations related to the vesting. The Partnership received no proceeds for issuing phantom units and none of the phantom units that vested were redeemed by the Partnership for cash. The amounts paid by the Partnership for income tax withholdings related to the vesting of awards under the 2002 LTIP were $0.4 million for the year ended December 31, 2011. The total fair value and intrinsic value of the phantom units vested under the 2002 LTIP was $1.0 million during the year ended December 31, 2011.