Equity-Based Compensation of the Operating Partnership

As discussed in Note 13, the Operating Partnership and the Company have a joint plan whereby equity based and performance based awards may be granted to directors, officers and employees. When shares are issued by the Company, the Operating Partnership issues corresponding units to the Company based on the current exchange ratio as provided by the Operating Partnership agreement. Based on the current exchange ratio, each unit in the Operating Partnership is equivalent to four common shares of the Company. Therefore, when the Company grants an equity based award, the Operating Partnership treats each award as having been granted by the Operating Partnership.

The tables below set forth the unit based compensation expense and other related information as recognized in the Operating Partnership's consolidated financial statements.

We recorded equity-based compensation expense in our statements of operations as follows (in thousands):



	Three Months Ended June 30,				Six Months Ended June 30,
	2011		2010		2011		2010
Restricted units	$	1,266	$	1,006	$	2,533	$	1,965
Notional unit performance awards	507		450		1,013		717
Options	47		—		72		—
Total equity-based compensation	$	1,820	$	1,456	$	3,618	$	2,682

Options outstanding at June 30, 2011 had the following weighted average exercise prices and weighted average remaining contractual lives:



	Options Outstanding				Options Exercisable
Range of exercise prices	Options	Weighted-average exercise price		Weighted-average remaining contractual life in years	Options	Weighted-average exercise price
$38.76	2,500	$	38.76	2.83	2,500	$	38.76
$38.83	23,425	38.83		2.83	23,425	38.83
$47.25	3,000	47.25		3.34	3,000	47.25
$104.24	46,250	104.24		9.66	—	—
	75,175	$	79.41	7.05	28,925	$	19.85

A summary of option activity under our Amended and Restated Incentive Award Plan as of June 30, 2011 and changes during the year then ended is presented below (aggregate intrinsic value amount in thousands):



Options	Units		Weighted-average exercise price		Weighted-average remaining contractual life in years	Aggregate intrinsic value
Outstanding as of December 31, 2010	30,050		$	39.66
Granted	47,875		104.24
Exercised	(1,125	)	38.83
Forfeited	(1,625	)	104.24
Outstanding as of June 30, 2011	75,175		$	79.41	7.05	$	1,945

Vested and Expected to Vest as of
June 30, 2011	64,976		$	75.51	6.64	$	1,934

Exercisable as of June 30, 2011	28,925		$	39.7	2.88	$	1,897

The total intrinsic value of options exercised during the three and six months ended June 30, 2011 was $78,000.

The following table summarizes information related to unvested restricted units outstanding as of June 30, 2011:



Unvested Restricted Units	Number of units		Weighted-average grant date fair value
Unvested at December 31, 2010	179,440		$	71.81
Granted	81,000		101.74
Vested	(51,900	)	71.47
Forfeited	(5,800	)	35.57
Unvested at June 30, 2011	202,740		$	83.69

The total value of restricted units vested during the six months ended June 30, 2011 was $5.5 million.

As of June 30, 2011, there was $23.4 million of total unrecognized compensation cost related to unvested share-based compensation arrangements granted under the Plan. That cost is expect to be recognized over a weighted-average period of 3.6 years.