Derivative Instruments and Hedging Activities Derivative Instruments and Hedging Activities (Tables)

6 Months Ended

Jun. 30, 2015

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block]

Derivative Instrument	Notional Amount		Effective Date	Maturity Date	Strike Rate		Balance Sheet Location	Fair Value
	(in thousands)							(in thousands)
Boston Properties Limited Partnership:
Interest Rate Swap	$	50,000	September 1, 2016	September 1, 2026	2.571	%	Prepaid Expenses and Other Assets	$	1,003
Interest Rate Swap	75,000		September 1, 2016	September 1, 2026	2.476	%	Prepaid Expenses and Other Assets	2,172
Interest Rate Swap	50,000		September 1, 2016	September 1, 2026	2.523	%	Prepaid Expenses and Other Assets	1,215
Interest Rate Swap	50,000		September 1, 2016	September 1, 2026	2.480	%	Prepaid Expenses and Other Assets	1,402
Interest Rate Swap	25,000		September 1, 2016	September 1, 2026	2.348	%	Prepaid Expenses and Other Assets	1,008
Interest Rate Swap	25,000		September 1, 2016	September 1, 2026	2.249	%	Prepaid Expenses and Other Assets	1,208
Interest Rate Swap	25,000		September 1, 2016	September 1, 2026	2.242	%	Prepaid Expenses and Other Assets	1,242
Interest Rate Swap	25,000		September 1, 2016	September 1, 2026	2.541	%	Prepaid Expenses and Other Assets	567
	$	325,000			2.458	%		$	9,817
767 Fifth Partners LLC:
Interest Rate Swap	$	25,000	June 7, 2017	June 7, 2027	2.683	%	Prepaid Expenses and Other Assets	$	618
Interest Rate Swap	50,000		June 7, 2017	June 7, 2027	2.677	%	Prepaid Expenses and Other Assets	1,261
Interest Rate Swap	25,000		June 7, 2017	June 7, 2027	2.913	%	Prepaid Expenses and Other Assets	123
Interest Rate Swap	25,000		June 7, 2017	June 7, 2027	2.857	%	Prepaid Expenses and Other Assets	244
Interest Rate Swap	25,000		June 7, 2017	June 7, 2027	2.950	%	Prepaid Expenses and Other Assets	43
	$	150,000			2.793	%		$	2,289
	$	475,000						$	12,106

Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss) [Table Text Block]

The following table presents the location in the financial statements of the gains or losses recognized related to the Company's cash flow hedges for the three and six months ended June 30, 2015 and 2014:

	Three months ended June 30,						Six months ended June 30,
	2015			2014			2015			2014
	(in thousands)						(in thousands)
Amount of gain related to the effective portion recognized in other comprehensive income (loss)	$	15,639		$	—		$	12,106		$	—
Amount of loss related to the effective portion subsequently reclassified to earnings (1)	$	(628	)	$	(624	)	$	(1,255	)	$	(1,253	)
Amount of gain (loss) related to the ineffective portion and amount excluded from effectiveness testing	$	—		$	—		$	—		$	—

___________

(1) Consists of amounts from previous interest rate hedging programs.

Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]

The following table reflects the changes in accumulated other comprehensive income (loss) for the six months ended June 30, 2015 and 2014 (in thousands):

Balance at December 31, 2014	$	(9,304	)
Effective portion of interest rate contracts	12,106
Amortization of interest rate contracts (1)	1,255
Other comprehensive income attributable to noncontrolling interests	(2,209		)
Balance at June 30, 2015	$	1,848
Balance at December 31, 2013	$	(11,556	)
Amortization of interest rate contracts (1)	1,253
Other comprehensive income attributable to noncontrolling interests	(126		)
Balance at June 30, 2014	$	(10,429	)

___________

(1) Consists of amounts from previous interest rate hedging programs.