Summary Of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2021

Summary Of Significant Accounting Policies [Line Items]

Property, Plant and Equipment

Depreciation is computed on a straight-line basis over the estimated useful lives of the assets as follows:

Land improvements	25 to 40 years
Buildings and improvements	10 to 40 years
Tenant improvements	Shorter of useful life or terms of related lease
Furniture, fixtures, and equipment	3 to 7 years

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense

The following table summarizes the scheduled amortization of the Company’s acquired “above-” and “below-market” lease intangibles for each of the five succeeding years (in thousands).

	Acquired Above-Market Lease Intangibles		Acquired Below-Market Lease Intangibles
2022	$	428	$	7,119
2023	208		5,334
2024	147		3,806
2025	135		3,775
2026	135		2,843

Fair Value Measurement Inputs and Valuation Techniques [Table Text Block]

Recurring Fair Value of Financial Instruments

The Company follows the authoritative guidance for fair value measurements when valuing its financial instruments for disclosure purposes. The table below presents for December 31, 2021 and 2020, the financial instruments that are being valued for disclosure purposes as well as the Level at which they are categorized as defined in ASC 820 “Fair Value Measurements and Disclosures” (“ASC 820”).

Financial Instrument	Level
Unsecured senior notes (1)	Level 1
Related party note receivable	Level 3
Notes receivable	Level 3
Mortgage notes payable	Level 3
Unsecured line of credit	Level 3
Unsecured term loan (2)	Level 3

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(1) If trading volume for the period is low, the valuation could be categorized as Level 2.

(2) As of December 31, 2021, the unsecured term loan had been repaid and was no longer outstanding.

Fair Value, by Balance Sheet Grouping [Table Text Block]

The following table presents the aggregate carrying value of the Company’s related party note receivable, net, notes receivable, net, mortgage notes payable, net, unsecured senior notes, net, unsecured line of credit and unsecured term loan, net and the Company’s corresponding estimate of fair value as of December 31, 2021 and December 31, 2020 (in thousands):

	December 31, 2021				December 31, 2020
	Carrying Amount		Estimated Fair Value		Carrying Amount		Estimated Fair Value
Related party note receivable, net	$	78,336	$	82,867	$	77,552	$	84,579
Note receivable, net	9,641		10,000		18,729		19,372
Total	$	87,977	$	92,867	$	96,281	$	103,951
Mortgage notes payable, net	$	3,267,914	$	3,395,569	$	2,909,081	$	3,144,150
Unsecured senior notes, net	9,483,695		9,966,591		9,639,287		10,620,527
Unsecured line of credit	145,000		145,317		—		—
Unsecured term loan, net	—		—		499,390		500,326
Total	$	12,896,609	$	13,507,477	$	13,047,758	$	14,265,003

Dividends Declared

The following table presents Boston Properties, Inc.’s dividends per share and Boston Properties Limited Partnership’s distributions per OP Unit and LTIP Unit paid or declared during the years ended December 31, 2021, 2020 and 2019:

Record Date	Payment Date	Dividend (Per Share)	Distribution (Per Unit)
December 31, 2021	January 28, 2022	$0.98	$0.98
September 30, 2021	October 29, 2021	$0.98	$0.98
June 30, 2021	July 30, 2021	$0.98	$0.98
March 31, 2021	April 30, 2021	$0.98	$0.98
December 31, 2020	January 28, 2021	$0.98	$0.98
September 30, 2020	October 30, 2020	$0.98	$0.98
June 30, 2020	July 31, 2020	$0.98	$0.98
March 31, 2020	April 30, 2020	$0.98	$0.98
December 31, 2019	January 30, 2020	$0.98	$0.98
September 30, 2019	October 31, 2019	$0.95	$0.95
June 28, 2019	July 31, 2019	$0.95	$0.95
March 29, 2019	April 30, 2019	$0.95	$0.95
December 31, 2018	January 30, 2019	$0.95	$0.95

Dividend Paid [Member]

Summary Of Significant Accounting Policies [Line Items]

Dividends Declared

The tax treatment of common dividends per share for federal income tax purposes is as follows: 

	For the year ended December 31,
	2021					2020					2019
	Per Share			%		Per Share			%		Per Share			%
Ordinary income	$	2.90		73.86	%	$	2.52		64.91	%	$	2.99		94.84	%
Capital gain income	0.57			14.57	%	0.99			25.49	%	0.16			5.16	%
Return of capital	0.45			11.57	%	0.37			9.60	%	—			—	%
Total	$	3.92	(1)	100.00	%	$	3.88	(2)	100.00	%	$	3.15	(3)	100.00	%

 _____________

(1)The fourth quarter 2021 regular quarterly dividend was $0.98 per common share, all of which was allocable to 2022.

(2)The fourth quarter 2020 regular quarterly dividend was $0.98 per common share, all of which was allocable to 2021.

(3)The fourth quarter 2019 regular quarterly dividend was $0.98 per common share of which approximately $0.04 per common share was allocable to 2019 and approximately $0.94 per common share was allocable to 2020.