Income per Common Unit of the Operating Partnership

12 Months Ended

Dec. 31, 2014

Earnings Per Unit, Basic and Diluted [Line Items]

Earnings per common unit of the Operating Partnership [Text Block]

INCOME PER COMMON SHARE OF THE TRUST

The following table sets forth the computation of basic and diluted income per common share of the Trust (in thousands except per share amounts):

	2014					2013
	Income (Numerator)		Weighted Average Shares (Denominator)	Per Share		Income (Numerator)		Weighted Average Shares (Denominator)	Per Share
Basic income from continuing operations
Income from continuing operations net of noncontrolling interest	$	170,471	147,216	$	1.16	$	91,274	130,180	$	0.70
Dilutive shares for long-term compensation plans	—		670			—		729
Diluted income from continuing operations
Income from continuing operations net of noncontrolling interest	170,471		147,886	$	1.15	91,274		130,909	$	0.70
Basic income from discontinued operations
Discontinued operations net of noncontrolling interest	47,439		147,216	$	0.32	118,464		130,180	$	0.91
Dilutive shares for long-term compensation plans	—		670			—		729
Diluted income from discontinued operations
Discontinued operations net of noncontrolling interest	47,439		147,886	$	0.32	118,464		130,909	$	0.90
Basic income per common share
Net income available to common shareholders	217,910		147,216	$	1.48	209,738		130,180	$	1.61
Dilutive shares for long-term compensation plans	—		670			—		729
Diluted income per common share
Net income available to common shareholders	$	217,910	147,886	$	1.47	$	209,738	130,909	$	1.60

	2012
	Income (Numerator)		Weighted Average Shares (Denominator)	Per Share
Basic income from continuing operations
Income from continuing operations net of noncontrolling interest	$	88,008	116,863	$	0.75
Dilutive shares for long-term compensation plans	—		831
Diluted income from continuing operations
Income from continuing operations net of noncontrolling interest	88,008		117,694	$	0.75
Basic income from discontinued operations
Discontinued operations net of noncontrolling interest	49,428		116,863	$	0.43
Dilutive shares for long-term compensation plans	—		831
Diluted income from discontinued operations
Discontinued operations net of noncontrolling interest	49,428		117,694	$	0.42
Basic income per common share
Net income available to common shareholders	137,436		116,863	$	1.18
Dilutive shares for long-term compensation plans	—		831
Diluted income per common share
Net income available to common shareholders	$	137,436	117,694	$	1.17

Dilutive shares for long-term compensation plans represent the unvested common shares outstanding during the year as well as the dilutive effect of outstanding options. The amounts of anti-dilutive options that were excluded from the computation of diluted income per common share as the exercise price was higher than the average share price of the Company in 2014, 2013 and 2012 were 850,000, 959,000 and 905,000, respectively.

Stock option exercises [Text Block]

During the years ended December 31, 2014, 2013 and 2012, 44,000, 504,000 and 841,000 common shares, respectively, were issued upon the exercise of options.

SHARE-BASED COMPENSATION

Compensation Plans

The Company has a share-based compensation plan (the "Plan") which is utilized to compensate key employees and non-employee trustees. In addition, the Company has a 2008 Long-Term Incentive Plan (the "2008 Plan") which is applicable to the Company's executive officers. Pursuant to both the Plan and the 2008 Plan, grants of stock options, restricted shares and restricted stock units have been made. The Company has authorized the grant of shares and options under the Plan and the 2008 Plan of up to 21.1 million common shares of the Company.

Options

All options granted have a 10-year term and most options vest and are expensed over a 3-year period, with options to purchase up to 20% of the shares exercisable after the first anniversary, up to 50% after the second anniversary and 100% after the third anniversary of the date of grant.

Share-based compensation cost related to options for the years ended December 31, 2014, 2013 and 2012 was $1.8 million, $1.6 million and $1.7 million, respectively.

The fair value of share option awards is estimated on the date of the grant using the Black-Scholes option valuation model. The following weighted-average assumptions were utilized in calculating the fair value of options granted during the periods indicated:

	Year Ended December 31,
	2014	2013	2012
Risk-free interest rate	1.6%	1.1%	1.1%
Dividend yield	5.2%	5.4%	5.7%
Historical volatility factor	0.236	0.356	0.377
Weighted-average expected life	6 years	6 years	5 years

The historical volatility factor is based on the Company's historical monthly share prices. The weighted-average expected life is based on the contractual term of the options as well as the historical periods held before exercise.

A summary of the Company's share option activity and related information for the year ended December 31, 2014 follows:

	Options (000s)		Weighted Average Exercise Price
Outstanding January 1, 2014	2,355		$	36.90
Granted	439		37.32
Exercised	(44	)	30.66
Forfeited	(258	)	42.69
Outstanding December 31, 2014	2,492		$	36.48
Exercisable at December 31, 2014	1,750		$	36.16

The weighted average fair value of options granted during the years ended December 31, 2014, 2013 and 2012 was $4.09, $7.18 and $6.55, respectively. Exercise prices for options outstanding as of December 31, 2014 ranged from $20.32 to $49.74. At December 31, 2014, the weighted average remaining contractual life of the options outstanding and exercisable was 5.4 years and 4.0 years, respectively.

During the years ended December 31, 2014, 2013 and 2012, the total intrinsic value of share options exercised (the difference between the market price at exercise and the price paid by the individual to exercise the option) was $310,000, $4.9 million and $5.9 million, respectively. As of December 31, 2014, 565,000 of the options outstanding and exercisable had an exercise price higher than the closing price of the Company's common shares and are considered to have no intrinsic value at that date. As of December 31, 2014, 1.2 million options outstanding and exercisable had an exercise price lower than the closing price of the Company's common shares. The aggregate intrinsic value of these options was $6.8 million at that date. The total cash received from the exercise of options for the years ended December 31, 2014, 2013 and 2012 was $1.4 million, $15.2 million and $22.9 million, respectively. The Company has historically issued new shares to satisfy share option exercises.

As of December 31, 2014, there was $324,000 of unrecognized compensation costs related to nonvested options granted under the Plan. That cost is expected to be recognized over a weighted average period of 0.8 years.

Long Term Incentive Shares ("LTI")

Restricted LTI share grants made under the Plan are valued at the grant date fair value, which is the market price of the underlying common shares, and vest ratably over a 5-year period beginning with the first anniversary of the grant.

During 2014, 2013 and 2012, the Company granted restricted stock units to the executive officers pursuant to the 2008 Plan. For the chief executive officer's award, a portion of the restricted stock units will vest up to 272% at the end of a 3-year period for the 2014, 2013 and 2012 awards. For the other executives, a portion of the restricted stock units will vest up to 200% at the end of a 3-year period for the 2014, 2013 and 2012 awards. A portion ("First Portion") of the award vests based on whether the Company's total return exceeds the average total returns of a selected group of peer companies. The grant date fair value of the First Portion was calculated based on a Monte Carlo simulation model and was determined to be 157%, 150% and 159% of the market value of a common share as of the grant date ("Market Value") for the chief executive officer and 125%, 121% and 127% of the Market Value for the other executives for the 2014, 2013 and 2012 grants, respectively. The First Portion is amortized over the respective 3-year period subject to certain accelerated vesting due to the age and years of service of certain executive officers. Another portion ("Second Portion") of the award vests based on the Company's Funds from operations. Targets are established for each of the 3 years in the relevant award period. Depending on how each year's performance compares to the projected performance for that year, the restricted stock units are deemed earned and will vest at the end of the award period. The fair value of the Second Portion is based on the market value of a common share as of the grant date and is being amortized to expense during the period from grant date to the vesting dates, adjusting for the expected level of vesting that is anticipated to occur at those dates also subject to certain accelerated vesting provisions as described above.

The key assumptions used in the Monte Carlo simulation are as follows:

	Year Ended December 31,
	2014	2013	2012
Risk-free interest rate	0.68%	0.35%	0.52%
Volatility	24%	26%	41%

The volatility factor is based on the Company's historical daily share prices.

Share-based compensation cost related to restricted LTI share grants for the years ended December 31, 2014, 2013 and 2012 were $9.0 million, $9.1 million and $8.7 million, respectively.

The Company's restricted LTI share activity for the year ended December 31, 2014 is as follows:

	Shares (000s)		Weighted Avg. Grant Date Fair value
Nonvested at January 1, 2014	786		$	35.37
Granted	263		37.13
Vested	(282	)	32.93
Forfeited	(14	)	36.19
Nonvested at December 31, 2014	753		$	36.89

The weighted average fair value of restricted shares granted during the years ended December 31, 2014, 2013 and 2012 was $37.13, $39.42 and $34.61 per share, respectively. As of December 31, 2014, there was $12.5 million of total unrecognized compensation cost related to nonvested shares granted under the Plan. That cost is expected to be recognized over a weighted average period of 1.4 years. The total fair value of restricted shares vested during the years ended December 31, 2014, 2013 and 2012 was $9.3 million, $9.9 million and $8.7 million, respectively.

Bonus Shares

The Plan provides that employees of the Company may elect to receive bonuses or commissions in the form of common shares in lieu of cash ("Bonus Shares"). By making such election, the employee receives shares equal to 120% of the cash value of the bonus or commission, less applicable withholding tax. Bonus Shares issued for the years ended December 31, 2014, 2013 and 2012 were 103,834, 79,271 and 80,573, respectively. Share-based compensation cost related to Bonus Shares for the years ended December 31, 2014, 2013 and 2012 was $3.9 million, $3.1 million and $2.9 million, respectively.

Profit Sharing Plan

The Plan provides that employees of the Company, below the officer level, may receive up to 5% of base pay in the form of cash contributions to an investment account depending on Company performance. Compensation cost related to the profit sharing plan for the years ended December 31, 2014, 2013 and 2012 was $543,000, $698,000 and $564,000 respectively.

An additional 6,100,098, 6,637,761 and 7,156,179 common shares were reserved for issuance for future grants under the Plan and the 2008 Plan at December 31, 2014, 2013 and 2012, respectively.

Employee Share Purchase Plan

The Company registered 750,000 common shares under the Securities Act of 1933, as amended, in connection with an employee share purchase plan ("ESPP"). The ESPP enables eligible employees to purchase shares of the Company, in amounts up to 10% of the employee's salary, at a 15% discount to fair market value. There were 12,612, 16,793 and 18,611 shares issued, in accordance with the ESPP, during the years ended December 31, 2014, 2013 and 2012, respectively. Share-based compensation cost related to the ESPP for the years ended December 31, 2014, 2013 and 2012 was $104,000, $71,000 and $99,000, respectively.

Unit conversions and dividends per share [Text Block]

During the years ended December 31, 2014, 2013 and 2012, individuals acquired 3,000, 157,285 and 94,895 common shares, respectively, in exchange for the same number of common units. These individuals acquired these common units in connection with their contributions to the Operating Partnership of certain assets in prior years. The exchange of common shares for the common units is exempt from the registration requirement of the Securities Act of 1933, as amended, pursuant to Section 4(2) thereunder.

During the years ended December 31, 2014, 2013 and 2012, distributions per common share were $1.90 for each period.

SHAREHOLDERS' EQUITY - TRUST

Common Shares

The Company paid to holders of its common shares and holders of its common units distributions of $286.9 million, $247.4 million and $229.7 million during the years ended December 31, 2014, 2013 and 2012, respectively. On a per share basis, the Company paid common share and common unit distributions of $1.90 during each of the years ended December 31, 2014, 2013 and 2012.

The following unaudited table summarizes the taxability of common share distributions (taxability for 2014 is estimated):

	2014		2013		2012
Ordinary dividend	$	1.2556	$	1.4312	$	1.5036
Capital gain - 20%	—		0.0016		—
IRC Sec 1250 unrecapture gain - 25%	0.3712		0.4672		0.0164
Return of capital	0.2732		—		0.3800
Total	$	1.9000	$	1.9000	$	1.9000

The Company's tax return for the year ended December 31, 2014 has not been filed. The taxability information presented for the 2014 distributions is based upon the best available data. The Company's prior federal income tax returns are subject to examination by taxing authorities. Because the application of tax laws and regulations is susceptible to varying interpretations, the taxability of distributions could be changed at a later date upon final determination by taxing authorities.

Common units

The common units of the Operating Partnership not held by the Trust outstanding as of December 31, 2014 have the same economic characteristics as common shares of the Trust. The 3,553,566 outstanding common units of the Operating Partnership not held by the Trust share proportionately in the net income or loss and in any distributions of the Operating Partnership. The common units of the Operating Partnership not held by the Trust are redeemable at any time at the option of the holder. The Trust, as the sole general partner of the Operating Partnership, may at its option elect to settle the redemption in cash or through the exchange on a one-for-one basis with unregistered common shares of the Trust. The market value of the 3,553,566 outstanding common units based on the closing price of the common shares of the Company at December 31, 2014 was $133.7 million.

No common units were issued in connection with acquisitions during 2014, 2013 or 2012.

Preferred units

The Operating Partnership had no outstanding cumulative redeemable preferred units of the Operating Partnership as of December 31, 2014. During the year ended December 31, 2013, the Company redeemed or repurchased $20.0 million of outstanding 7.00% Series E Cumulative Redeemable Preferred Units, $17.5 million of outstanding 6.65% Series F Cumulative Redeemable Preferred Units and $27.0 million of outstanding 6.70% Series G Cumulative Redeemable Preferred Units, all at par. In connection with these redemptions and repurchases, the Company wrote off $1.2 million in origination costs. This amount was included in noncontrolling interest - operating partnership in the Trust's consolidated statements of comprehensive income.

During the year ended December 31, 2012, the Company redeemed $32.5 million of outstanding 6.65% Series F Cumulative Redeemable Preferred Units for $26.0 million. Also, the Company redeemed $95.0 million of outstanding 7.45% Series B Cumulative Redeemable Preferred Units and $100.0 million of outstanding 7.40% Series H Cumulative Redeemable Preferred Units at par. In connection with these redemptions, during the year ended December 31, 2012, the Company recognized a $3.7 million net gain relating to the excess of preferred unit carrying amount over redemption price net of certain costs. This amount was included in noncontrolling interest - operating partnership in the Trust's consolidated statements of comprehensive income.

The Company paid the following Equity Preferred Unit distributions for the years ended December 31:

	2013	2012
Distributions (in millions)	$1.6	$9.9
Distribution per unit:
Series B	—	$0.45
Series E	$1.21	$3.50
Series F	$1.32	$1.43
Series G	$1.33	$3.35
Series H	—	$0.77

As of December 31, 2014, the Company had 16,013,000 authorized but unissued preferred shares.

Dividend Reinvestment and Share Purchase Plan

The Company has a Dividend Reinvestment and Share Purchase Plan under which holders of common shares may elect to automatically reinvest their distributions in additional common shares and may make optional cash payments for additional common shares. The Company may issue additional common shares or repurchase common shares in the open market for purposes of satisfying its obligations under the Dividend Reinvestment and Share Purchase Plan. During the years ended December 31, 2014, 2013, and 2012, 1,643,536, 1,248,842, and 1,037,712 common shares, respectively, were issued through the Dividend Reinvestment and Share Purchase Plan. The Company used the proceeds to pay down outstanding borrowings under the Company's Credit Facility and for general corporate purposes.

Continuous Equity Offering

The Company has a continuous equity offering program in place for up to $200 million of equity. During the year ended December 31, 2013, the Company sold 1.9 million common shares through this program. The aggregate proceeds from the offering of $75.0 million were used to pay down outstanding borrowings under the Company's unsecured credit facility and for general corporate purposes. The Company did not sell any common shares pursuant to its continuous offering program during 2014 or 2012.

Noncontrolling Interest - Consolidated Joint Ventures

Noncontrolling interest - consolidated joint ventures includes third-party ownership interests in consolidated joint venture investments.

Liberty Property Limited Partnership [Member]

Earnings Per Unit, Basic and Diluted [Line Items]

Earnings per common unit of the Operating Partnership [Text Block]

INCOME PER COMMON UNIT OF THE OPERATING PARTNERSHIP

The following table sets forth the computation of basic and diluted income per common unit of the Operating Partnership (in thousands, except per unit amounts):

	2014						2013
	Income (Numerator)			Weighted Average Units (Denominator)	Per Unit		Income (Numerator)			Weighted Average Units (Denominator)	Per Unit
Income from continuing operations net of noncontrolling interest - consolidated joint ventures	$	175,035					$	97,102
Less: Preferred unit distributions	(472		)				(2,119		)
Excess of preferred unit redemption over carrying amount	—						(1,236		)
Basic income from continuing operations
Income from continuing operations available to common unitholders	174,563			150,770	$	1.16	93,747			133,858	$	0.70
Dilutive units for long-term compensation plans	—			670			—			729
Diluted income from continuing operations
Income from continuing operations available to common unitholders	174,563			151,440	$	1.15	93,747			134,587	$	0.70
Basic income from discontinued operations
Discontinued operations	48,581			150,770	$	0.32	121,839			133,858	$	0.91
Dilutive units for long-term compensation plans	—			670			—			729
Diluted income from discontinued operations
Discontinued operations	48,581			151,440	$	0.32	121,839			134,587	$	0.90
Basic income per common unit
Income available to common unitholders	223,144			150,770	$	1.48	215,586			133,858	$	1.61
Dilutive units for long-term compensation plans	—			670			—			729
Diluted income per common unit
Income available to common unitholders	$	223,144		151,440	$	1.47	$	215,586		134,587	$	1.60

	2012
	Income (Numerator)			Weighted Average Units (Denominator)	Per Unit
Income from continuing operations net of noncontrolling interest - consolidated joint ventures	$	97,022
Less: Preferred unit distributions	(9,902		)
Excess of preferred unit carrying amount over redemption	3,689
Basic income from continuing operations
Income from continuing operations available to common unitholders	90,809			120,623	$	0.75
Dilutive units for long-term compensation plans	—			831
Diluted income from continuing operations
Income from continuing operations available to common unitholders	90,809			121,454	$	0.75
Basic income from discontinued operations
Discontinued operations	51,004			120,623	$	0.43
Dilutive units for long-term compensation plans	—			831
Diluted income from discontinued operations
Discontinued operations	51,004			121,454	$	0.42
Basic income per common unit
Income available to common unitholders	141,813			120,623	$	1.18
Dilutive units for long-term compensation plans	—			831
Diluted income per common unit
Income available to common unitholders	$	141,813		121,454	$	1.17

Dilutive units for long-term compensation plans represent the unvested common units outstanding during the year as well as the dilutive effect of outstanding options. The amounts of anti-dilutive options that were excluded from the computation of diluted income per common unit as the exercise price was higher than the average unit price of the Company in 2014, 2013 and 2012 were 850,000, 959,000 and 905,000, respectively.

Stock option exercises [Text Block]

During the years ended December 31, 2014, 2013 and 2012, 44,000, 504,000 and 841,000 common units, respectively, were issued upon the exercise of options.

Unit conversions and dividends per share [Text Block]

During the years ended December 31, 2014, 2013 and 2012, individuals acquired 3,000, 157,285 and 94,895 common shares of the Trust in exchange for the same number of common units of the Operating Partnership. These individuals acquired these common units in connection with their contributions to the Operating Partnership of certain assets in prior years. The exchange of common shares for the common units is exempt from the registration requirement of the Securities Act of 1933, as amended, pursuant to Section 4(2) thereunder.

During the years ended December 31, 2014, 2013 and 2012, distributions per common unit were $1.90 for each period.