Compensatory Unit Awards and Option Plans (Tables)

12 Months Ended

Dec. 31, 2012

Compensatory Unit Awards and Option Plans [Abstract]

Options to buy Holding Units (including grants to Eligible Directors) were granted as follows: 114,443 options were granted during 2012, 70,238 options were granted during 2011 and 387,661 options were granted during 2010. The weighted average fair value of options to buy Holding Units granted during 2012, 2011 and 2010 was $3.67, $5.98 and $6.18, respectively, on the date of grant, determined using the Black-Scholes option valuation model with the following assumptions:

	2012			2011			2010

Risk-free interest rate		0.7	%		1.9	%		2.2 – 2.3	%
Expected cash distribution yield		6.2	%		5.4	%		7.2 – 8.2	%
Historical volatility factor		49.2	%		47.3	%		46.2 – 46.6	%
Expected term	6.0 years			6.0 years			6.0 years

Summary of option plan activity

The following table summarizes the activity in our option plan during 2012:

	Options to Buy Holding Units			Weighted Average Exercise Price Per Option		Weighted Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value

Outstanding as of December 31, 2011		8,994,229		$	39.63		6.4
Granted		114,443			14.58
Exercised		—			—
Forfeited		(11,500	)		33.18
Expired		(543,827	)		32.34
Outstanding as of December 31, 2012		8,553,345			39.77		5.8	$	—
Exercisable as of December 31, 2012		4,237,915			33.85		5.7		—
Vested or expected to vest as of December 31, 2012		8,553,345			39.77		5.8		—

Summary of unvested restricted Holding Units

The following table summarizes the activity of unvested restricted Holding Units during 2012:

	Holding Units			Weighted Average Grant Date Fair Value per Holding Unit

Unvested as of December 31, 2011		15,574,191		$	23.88
Granted		12,099,291			14.48
Vested		(8,507,437	)		21.65
Forfeited		(728,556	)		20.67
Unvested as of December 31, 2012		18,437,489			18.79