Summary of Significant Accounting Policies and Procedures and Recent Accounting Pronouncements (Tables)

12 Months Ended

Dec. 31, 2018

Accounting Policies [Abstract]

Schedule of reconciliation of the denominator of the basic net income per common share computation to the denominator of the diluted net income per common share computation

The following is a reconciliation of the denominator of the basic net income per common share computation to the denominator of the diluted net income per common share computation.

	2018	2017	2016
Weighted average shares used for the basic net income per share computation	289,427,430	273,465,680	255,066,500
Incremental shares from share-based compensation	179,532	154,050	240,728
Weighted average partnership common units convertible to common shares that were dilutive	317,022	317,022	317,022
Weighted average shares used for diluted net income per share computation	289,923,984	273,936,752	255,624,250
Unvested shares from share-based compensation that were anti-dilutive	13,148	32,205	475
Weighted average partnership common units convertible to common shares that were anti-dilutive	297,576	88,182	198,429

Estimated useful lives of properties

Properties are depreciated using the straight-line method over the estimated useful lives of the assets.  The estimated useful lives are as follows:

Buildings	25 years or 35 years
Building improvements	4 to 20 years
Tenant improvements and lease commissions	The shorter of the term of the related lease or useful life
Acquired in-place leases	Remaining terms of the respective leases