Stock Based Compensation

12 Months Ended

Dec. 31, 2011

Stock Based Compensation [Abstract]

Disclosure of Compensation Related Costs, Share-based Payments [Text Block]

Stock Based Compensation

The General Partner is authorized to issue up to 11.9 million shares of its common stock under its stock based employee and non-employee compensation plans.

Fixed Stock Option Plans

On June 7, 2010, the General Partner completed a one-time stock option exchange program, which was approved by the General Partner's shareholders at its annual meeting, to allow the majority of its employees to surrender for cancellation their outstanding stock options in exchange for a lesser number of restricted stock units (“RSUs”) based on both the fair value of the options and the RSUs at the time of the exchange. As a result of the program, 4.4 million options were surrendered and cancelled and 1.2 million RSUs were granted.

The total compensation cost for the new RSUs, which is equal to the unamortized compensation expense associated with the related eligible unvested options surrendered, will be recognized over the applicable vesting period of the new RSUs. As the fair value of the RSUs granted was less than the fair value of the eligible options surrendered in exchange for the RSUs, each measured on June 7, 2010, there was no incremental expense recognized through the exchange program. The most significant assumption used in estimating the fair value of the surrendered options was the assumption for expected volatility, which was 70%. The volatility assumption was made based on both historical experience and our best estimate of future volatility. The assumption for dividend yield was 5% while the assumptions for expected term and risk-free rate varied based upon the remaining contractual lives of the surrendered options.

Compensation expense recognized for fixed stock option plans was insignificant during the year ended December 31, 2011 and was $820,000 and $2.6 million, respectively, for the years ended December 31, 2010 and December 31, 2009.

Restricted Stock Units

Under the General Partner's 2005 Long-Term Incentive Plan and its 2005 Non-Employee Directors Compensation Plan (collectively, the "Compensation Plans") approved by its shareholders in April 2005, RSUs may be granted to non-employee directors, executive officers and selected management employees. An RSU is economically equivalent to one share of the General Partner's common stock.

RSUs granted to employees generally vest 20% per year over five years, have contractual lives of five years and are payable in shares of the General Partner's common stock with a new share of such common stock issued upon each RSU’s vesting. RSUs granted to existing non-employee directors vest 100% over one year, and have contractual lives of one year. RSUs granted on June 7, 2010 in exchange for stock options will vest, depending on the original terms of the surrendered options, over either one or two years.

To the extent that a recipient of an RSU grant is not determined to be retirement eligible, as defined by the Compensation Plans, we recognize expense on a straight-over basis over their vesting periods. Expense is recognized immediately at the date of grant to the extent a recipient is retirement eligible and expense is accelerated to the extent that a participant will become retirement eligible prior to the end of the contractual life of granted RSUs.

The following table summarizes transactions for our RSUs, excluding dividend equivalents, for 2011:

Restricted Stock Units	Number of RSUs		Weighted Average Grant Date Fair Value
RSUs at December 31, 2010	3,378,839		$11.15
Granted	867,030		$13.66
Vested	(577,344	)	$12.11
Forfeited	(165,125	)	$11.51
RSUs at December 31, 2011	3,503,400		$11.59

Compensation cost recognized for RSUs totaled $11.2 million, $9.0 million and $7.3 million for the years ended December 31, 2011, 2010 and 2009, respectively.

As of December 31, 2011, there was $14.5 million of total unrecognized compensation expense related to nonvested RSUs granted under the Plan, which is expected to be recognized over a weighted average period of 3.2 years.