Share and Unit-Based Plans (Tables)

6 Months Ended

Jun. 30, 2016

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

Compensation cost under the share and unit-based plans

The following summarizes the compensation cost under the share and unit-based plans:



	For the Three Months Ended June 30,				For the Six Months Ended June 30,
	2016		2015		2016		2015
LTIP Units	$	5,149	$	3,770	$	22,548	$	18,998
Stock awards	—		122		20		197
Stock units	1,002		1,136		4,374		4,333
Stock options	4		4		8		8
Phantom stock units	194		268		798		579
	$	6,349	$	5,300	$	27,748	$	24,115

Summary of activity of non-vested LTIP Units, stock awards, phantom stock and stock units

The following table summarizes the activity of the non-vested LTIP Units, stock awards, phantom stock units and stock units:



	LTIP Units				Stock Awards				Phantom Stock Units				Stock Units
	Units		Value(1)		Shares		Value(1)		Units		Value(1)		Units		Value(1)
Balance at January 1, 2016	56,315		$	73.24	1,612		$	62.01	—		$	—	132,086		$	74.58
Granted	480,371		65.00		—		—		17,578		80.39		85,221		79.24
Vested	(154,686	)	79.20		(1,612	)	62.01		(9,714	)	80.54		(68,879	)	71.81
Forfeited	—		—		—		—		—		—		—		—
Balance at June 30, 2016	382,000		$	60.47	—		$	—	7,864		$	80.20	148,428		$	78.53

(1) Value represents the weighted average grant date fair value.

Summary of activity of SARs and stock options outstanding

The following table summarizes the activity of the stock appreciations rights ("SARs") and stock options outstanding:



	SARs				Stock Options
	Units		Value(1)		Units	Value(1)
Balance at January 1, 2016	417,783		$	55.13	10,314	$	58.15
Granted	—		—		—	—
Exercised	(58,087	)	53.88		—	—
Special dividend adjustment (2)	10,185		53.88		251	56.77
Balance at June 30, 2016	369,881		$	53.88	10,565	$	56.77

(1) Value represents the weighted average exercise price.

(2) The exercise price and number of units were adjusted such that each unit had the same fair value to the holder before and after giving effect to the payout of the Special Dividend paid on January 6, 2016 (See Note 12—Stockholders' Equity).