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

12 Months Ended

Dec. 31, 2017

Summary of Significant Accounting Policies and Procedures and Recent Accounting Pronouncements

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

	2017	2016	2015
Weighted average shares used for the basic net income per share computation	273,465,680	255,066,500	235,767,932
Incremental shares from share-based compensation	154,050	240,728	123,436
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	273,936,752	255,624,250	236,208,390
Unvested shares from share-based compensation that were anti-dilutive	32,205	475	106,103
Weighted average partnership common units convertible to common shares that were anti-dilutive	88,182	198,429	417,060

Estimated useful lives of properties

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