Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2018

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

Schedule of Nonvested Share Activity [Table Text Block]

The following table summarizes non-vested restricted stock activity:



		Year ended December 31, 2018
		Number of Shares			Intrinsic Value (in thousands)		Weighted Average Grant Price
Non-vested as of December 31, 2017		570,077
Time-based awards granted^{(1) (4)}		130,584					$61.66
Performance-based awards granted ^{(2) (4)}		14,935					$62.57
Market-based awards granted ^{(3) (4)}		113,126					$65.74
Change in market-based awards earned for performance ⁽³⁾		64,330					$60.34
Vested ⁽⁵⁾		(287,331		)			$60.23
Forfeited		(10,550		)			$68.65
Non-vested as of December 31, 2018 ⁽⁶⁾		595,171			$34,925

⁽¹⁾ Time-based awards vest beginning on the first anniversary following the grant date over a three or four year service period. These grants are subject only to continued employment and are not dependent on future performance measures. Accordingly, if such vesting criteria are not met, compensation cost previously recognized would be reversed.
⁽²⁾ Performance-based awards are earned subject to future performance measurements. Once the performance criteria are achieved and the actual number of shares earned is determined, shares vest over a required service period. The Company considers the likelihood of meeting the performance criteria based upon management's estimates from which it determines the amounts recognized as expense on a periodic basis.
⁽³⁾ Market-based awards are earned dependent upon the Company's total shareholder return in relation to the shareholder return of a NAREIT index over a three-year period. Once the performance criteria are met and the actual number of shares earned is determined, the shares are immediately vested and distributed. The probability of meeting the criteria is considered when calculating the estimated fair value on the date of grant using a Monte Carlo simulation. These awards are accounted for as awards with market criteria, with compensation cost recognized over the service period, regardless of whether the performance criteria are achieved and the awards are ultimately earned. The significant assumptions underlying determination of fair values for market-based awards granted were as follows:

		Year ended December 31,
		2018			2017		2016
	Volatility	19.20%			18.00%		18.50%
	Risk free interest rate	2.26%			1.48%		0.88%

⁽⁴⁾The weighted-average grant price for restricted stock granted during the years is summarized below:

		Year ended December 31,
		2018			2017		2016
	Weighted-average grant price for restricted stock	$	63.50		$	72.05	$	79.40

⁽⁵⁾ The total intrinsic value of restricted stock vested during the years is summarized below (in thousands):

		Year ended December 31,
		2018			2017		2016
	Intrinsic value of restricted stock vested	$	17,306		$	14,376	$	15,400

⁽⁶⁾As of December 31, 2018, there was $13.1 million of unrecognized compensation cost related to non-vested restricted stock granted under the Parent Company's Plan. When recognized, this compensation results in additional paid in capital in the accompanying Consolidated Statements of Equity of the Parent Company and in general partner preferred and common units in the accompanying Consolidated Statements of Capital of the Operating Partnership. This unrecognized compensation cost is expected to be recognized over the next three years. The Company issues new restricted stock from its authorized shares available at the date of grant.

Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block]

The Company recorded stock-based compensation in general and administrative expenses in the accompanying Consolidated Statements of Operations, the components of which are further described below:



	Year ended December 31,
(in thousands)	2018			2017		2016
Restricted stock ⁽¹⁾	$	16,745		15,525		13,422
Directors' fees paid in common stock ⁽¹⁾	399			303		193
Capitalized stock-based compensation ⁽²⁾	(3,509		)	(3,210	)	(2,963	)
Stock based compensation attributable to post-combination service from Equity One merger	—			7,931		—
Stock-based compensation, net of capitalization	$	13,635		20,549		10,652

⁽¹⁾Includes amortization of the grant date fair value of restricted stock awards over the respective vesting periods.
⁽²⁾Includes compensation expense specifically identifiable to development and leasing activities.

The Company established its Long Term Omnibus Plan (the "Plan") under which the Board of Directors may grant stock options and other stock-based awards to officers, directors, and other key employees. The Plan allows the Company to issue up to 4.1 million shares in the form of the Parent Company's common stock or stock options. As of December 31, 2018, there were 1.2 million shares available for grant under the Plan either through stock options or restricted stock.