Share and Unit-Based Plans:

Under the Long-Term Incentive Plan ("LTIP"), each award recipient is issued a form of units ("LTIP Units") in the Operating Partnership. Upon the occurrence of specified events and subject to the satisfaction of applicable vesting conditions, LTIP Units (after conversion into OP Units) are ultimately redeemable for common stock of the Company, or cash at the Company's option, on a one-unit for one-share basis. LTIP Units receive cash dividends based on the dividend amount paid on the common stock of the Company. The LTIP may include both market-indexed awards and service-based awards.

The market-indexed LTIP Units vest over the service period of the award based on the percentile ranking of the Company in terms of total return to stockholders (the "Total Return") per share of common stock relative to the Total Return of a group of peer REITs, as measured at the end of the measurement period.

During the three months ended March 31, 2019, the Company granted the following LTIP Units:



Grant Date	Units	Type	Fair Value per LTIP Unit		Vest Date
1/1/2019	81,732	Service-based	$	43.28	12/31/2021
1/1/2019	250,852	Market-indexed	$	29.25	12/31/2021
	332,584

The fair value of the market-indexed LTIP Units (Level 3) granted on January 1, 2019 was estimated on the date of grant using a Monte Carlo Simulation model that assumed a risk free interest rate of 2.46% and an expected volatility of 23.52%.

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



	LTIP Units				Phantom Stock Units				Stock Units
	Units		Value(1)		Units		Value(1)		Units		Value(1)
Balance at January 1, 2019	661,578		$	48.38	—		$	—	129,457		$	64.21
Granted	332,584		32.70		18,315		43.13		89,505		42.00
Vested	(7,654	)	59.85		(3,934	)	45.55		(80,954	)	64.53
Forfeited	(14,635	)	34.26		—		—		—		—
Balance at March 31, 2019	971,873		$	43.13	14,381		$	42.46	138,008		$	49.62


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

The following table summarizes the activity of the stock options outstanding:



	Stock Options
	Units	Value(1)
Balance at January 1, 2019	35,565	$	57.32
Granted	—	—
Exercised	—	—
Balance at March 31, 2019	35,565	$	57.32


(1) Value represents the weighted average exercise price.

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



	For the Three Months Ended March 31,
	2019		2018
LTIP Units	$	3,714	$	10,108
Stock units	2,660		3,230
Stock options	51		31
Phantom stock units	240		243
	$	6,665	$	13,612

The Company capitalized share and unit-based compensation costs of $1,146 and $2,609 for the three months ended March 31, 2019 and 2018, respectively. Unrecognized compensation costs of share and unit-based plans at March 31, 2019 consisted of $9,050 from LTIP Units, $2,921 from stock units and $611 from phantom stock units.