Dupont Fabros Technology 10-K 23 Feb 17 2016 Q4 Annual report Financial data

Document and Entity Information

Document and Entity Information Document - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Feb. 17, 2017	Jun. 30, 2016
Entity Information [Line Items]
Document Period End Date	Dec. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q4
Amendment Flag	false
Entity Registrant Name	DUPONT FABROS TECHNOLOGY, INC.
Entity Central Index Key	1,407,739
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Entity Common Stock, Shares Outstanding		77,498,011
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 3,561
Subsidiaries [Member]
Entity Information [Line Items]
Document Period End Date	Dec. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q4
Amendment Flag	false
Entity Registrant Name	DUPONT FABROS TECHNOLOGY, L.P.
Entity Central Index Key	1,418,175
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Document Type	10-K
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2016		Dec. 31, 2015
Income producing property:
Land	$ 105,890		$ 94,203
Buildings and improvements	3,018,361		2,736,936
Income producing property	3,124,251		2,831,139
Less: accumulated depreciation	(662,183)		(560,837)
Net income producing property	2,462,068		2,270,302
Construction in progress and land held for development	330,983	[1]	300,939
Net real estate	2,793,051		2,571,241
Cash and cash equivalents	38,624		31,230
Rents and other receivables	11,533		9,588
Deferred rent, net	123,058		128,941
Lease contracts above market value, net	5,138		6,029
Deferred costs, net	25,776		23,774
Prepaid expenses and other assets	41,284		44,689
Total assets	3,038,464		2,815,492
Liabilities:
Unsecured Credit Facility	50,926		0
Mortgage notes payable	110,733		114,075
Unsecured Term Loan	249,036		249,172
Unsecured notes payable	837,323		834,963
Accounts payable and accrued liabilities	36,909		32,301
Construction costs payable	56,428		22,043
Accrued interest payable	11,592		11,821
Dividend and distribution payable	46,352		43,906
Lease contracts below market value, net	2,830		4,132
Prepaid rents and other liabilities	78,232		67,477
Total liabilities	1,480,361		1,379,890
Redeemable noncontrolling interests - operating partnership	591,101		479,189
Redeemable noncontrolling interests - operating partnership	591,101		479,189
Commitments and contingencies	0		0
Stockholders’ equity:
Common stock, $.001 par value, 250,000,000 shares authorized, 75,914,763 shares issued and outstanding at December 31, 2016 and 66,105,650 shares issued and outstanding at December 31, 2015	76		66
Additional paid in capital	766,732		685,042
Retained Earnings (Accumulated Deficit)	0		(79,945)
Accumulated Other Comprehensive Income (Loss), Net of Tax	(1,056)		0
Total stockholders’ equity	967,002		956,413
Total liabilities and stockholders’ equity	3,038,464		2,815,492
Series A cumulative redeemable perpetual preferred stock [Member]
Stockholders’ equity:
Preferred stock, $.001 par value, 50,000,000 shares authorized	0		185,000
Series B cumulative redeemable perpetual preferred stock [Member]
Stockholders’ equity:
Preferred stock, $.001 par value, 50,000,000 shares authorized	0		166,250
Series C cumulative redeemable perpetual preferred stock [Member]
Stockholders’ equity:
Preferred stock, $.001 par value, 50,000,000 shares authorized	201,250		0
Subsidiaries [Member]
Income producing property:
Land	105,890		94,203
Buildings and improvements	3,018,361		2,736,936
Income producing property	3,124,251		2,831,139
Less: accumulated depreciation	(662,183)		(560,837)
Net income producing property	2,462,068		2,270,302
Construction in progress and land held for development	330,983		300,939
Net real estate	2,793,051		2,571,241
Cash and cash equivalents	34,409		27,015
Rents and other receivables	11,533		9,588
Deferred rent, net	123,058		128,941
Lease contracts above market value, net	5,138		6,029
Deferred costs, net	25,776		23,774
Prepaid expenses and other assets	41,284		44,689
Total assets	3,034,249		2,811,277
Liabilities:
Unsecured Credit Facility	50,926		0
Mortgage notes payable	110,733		114,075
Unsecured Term Loan	249,036		249,172
Unsecured notes payable	837,323		834,963
Accounts payable and accrued liabilities	36,909		32,301
Construction costs payable	56,428		22,043
Accrued interest payable	11,592		11,821
Dividend and distribution payable	46,352		43,906
Lease contracts below market value, net	2,830		4,132
Prepaid rents and other liabilities	78,232		67,477
Total liabilities	1,480,361		1,379,890
Redeemable noncontrolling interests - operating partnership	591,101		479,189
Redeemable noncontrolling interests - operating partnership	591,101		479,189
Commitments and contingencies	0		0
Stockholders’ equity:
Total liabilities and stockholders’ equity	3,034,249		2,811,277
Limited partners’ capital:
Limited partners' capital	201,250
General partner’s capital, common units, 662,373 issued and outstanding at December 31, 2016 and December 31, 2015	6,645		6,021
Total partners’ capital	962,787		952,198
Subsidiaries [Member] | Series A Preferred Units [Member]
Limited partners’ capital:
Limited partners' capital	0		185,000
Subsidiaries [Member] | Series B Preferred Units [Member]
Limited partners’ capital:
Limited partners' capital	0		166,250
Subsidiaries [Member] | Series C Preferred Units [Member]
Limited partners’ capital:
Limited partners' capital	201,250		0
Subsidiaries [Member] | Common units [Member]
Limited partners’ capital:
Limited partners' capital	$ 754,892		594,927
Subsidiaries [Member] | Series A cumulative redeemable perpetual preferred stock [Member]
Limited partners’ capital:
Limited partners' capital			185,000
Subsidiaries [Member] | Series B cumulative redeemable perpetual preferred stock [Member]
Limited partners’ capital:
Limited partners' capital			$ 166,250
[1]	(1)Properties located in Ashburn, VA (ACC8, ACC9, ACC10, and ACC11), Elk Grove Village, IL (CH3), Santa Clara, CA (SC1 Phase III, formerly referred to as SC2), Hillsboro, OR (OR1 and OR2) and Vaughan, ON (TOR1).

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2016	Dec. 31, 2015
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	50,000,000	50,000,000
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	75,914,763	66,105,650
Common stock, shares outstanding	75,914,763	66,105,650
General Partners' Capital Account, Units Issued	662,373	662,373
General partners' capital, units outstanding	662,373	662,373
Series A cumulative redeemable perpetual preferred units [Member]
Limited partners' capital, common units issued	0	7,400,000
Limited partners' capital, common units outstanding	0	7,400,000
Series B cumulative redeemable perpetual preferred units [Member]
Limited partners' capital, common units issued	0	6,650,000
Limited partners' capital, common units outstanding	0	6,650,000
Series C cumulative redeemable perpetual preferred units [Member]
Limited partners' capital, common units issued	8,050,000	0
Limited partners' capital, common units outstanding	8,050,000	0
Limited partners' common units [Member]
Limited partners' capital, common units issued	75,252,390	65,443,277
Limited partners' capital, common units outstanding	75,252,390	65,443,277
Series A cumulative redeemable perpetual preferred stock [Member]
Preferred stock, shares issued	0	7,400,000
Preferred stock, shares outstanding	0	7,400,000
Series B cumulative redeemable perpetual preferred stock [Member]
Preferred stock, shares issued	0	6,650,000
Preferred stock, shares outstanding	0	6,650,000
Series C cumulative redeemable perpetual preferred stock [Member]
Preferred stock, shares issued	8,050,000	0
Preferred stock, shares outstanding	8,050,000	0

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues:
Base rent	$ 345,022	$ 298,585	$ 285,716
Recoveries from tenants	169,668	139,537	124,853
Other revenues	14,011	14,278	7,023
Total revenues	528,701	452,400	417,592
Expenses:
Property operating costs	154,064	130,051	117,339
Real estate taxes and insurance	20,180	21,335	14,195
Depreciation and amortization	107,781	104,044	96,780
General and administrative	23,043	18,064	17,181
Impairment of Long-Lived Assets to be Disposed of	0	122,472	0
Other expenses	11,781	16,859	9,222
Total expenses	316,849	412,825	254,717
Operating income	211,852	39,575	162,875
Interest:
Expense incurred	(48,294)	(40,510)	(33,583)
Amortization of deferred financing costs	(3,712)	(3,151)	(2,980)
Gain (Loss) on Disposition of Property Plant Equipment	22,833	0	0
Loss on early extinguishment of debt	(1,232)	0	(1,701)
Net (loss) income	181,447	(4,086)	124,611
Noncontrolling Interest in Net Income (Loss) Operating Partnerships, Redeemable	24,248	(5,993)	18,704
Net (loss) income attributable to controlling interests	157,199	1,907	105,907
Preferred stock dividends	(20,739)	(27,245)	(27,245)
Other Preferred Stock Dividends and Adjustments	(12,495)	0	0
Net (loss) income attributable to common shares	123,965	(25,338)	78,662
Net income attributable to common units	$ 148,213	$ (31,331)	$ 97,366
Earnings per share – basic:
Net income attributable to common shares	$ 1.69	$ (0.40)	$ 1.19
Weighted average common shares outstanding	73,003,164	65,184,013	65,486,108
Earnings per share – diluted:
Net income attributable to common shares	$ 1.67	$ (0.40)	$ 1.18
Weighted average common shares outstanding	73,839,036	65,184,013	66,086,379
Earnings per unit – basic:
Net income attributable to common units	$ 1.69	$ (0.40)	$ 1.19
Earnings per unit – diluted:
Net income attributable to common units	$ 1.67	$ (0.40)	$ 1.18
Subsidiaries [Member]
Revenues:
Base rent	$ 345,022	$ 298,585	$ 285,716
Recoveries from tenants	169,668	139,537	124,853
Other revenues	14,011	14,278	7,023
Total revenues	528,701	452,400	417,592
Expenses:
Property operating costs	154,064	130,051	117,339
Real estate taxes and insurance	20,180	21,335	14,195
Depreciation and amortization	107,781	104,044	96,780
General and administrative	23,043	18,064	17,181
Impairment of Long-Lived Assets to be Disposed of	0	122,472	0
Other expenses	11,781	16,859	9,222
Total expenses	316,849	412,825	254,717
Operating income	211,852	39,575	162,875
Interest:
Expense incurred	(48,294)	(40,510)	(33,583)
Amortization of deferred financing costs	(3,712)	(3,151)	(2,980)
Gain (Loss) on Disposition of Property Plant Equipment	22,833	0	0
Loss on early extinguishment of debt	(1,232)	0	(1,701)
Net (loss) income	181,447	(4,086)	124,611
Preferred stock dividends	(20,739)	(27,245)	(27,245)
Other Preferred Stock Dividends and Adjustments	(12,495)	0	0
Net income attributable to common units	$ 148,213	$ (31,331)	$ 97,366
Earnings per unit – basic:
Net income attributable to common units	$ 1.69	$ (0.40)	$ 1.19
Weighted average common units outstanding	87,284,564	80,599,199	81,053,127
Earnings per unit – diluted:
Net income attributable to common units	$ 1.67	$ (0.40)	$ 1.18
Weighted average common units outstanding	88,120,436	80,599,199	81,653,398

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income Statement - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Net (loss) income	$ 181,447	$ (4,086)	$ 124,611
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Foreign currency translation adjustments	(1,257)	0	0
Comprehensive Income (Loss)	180,190	(4,086)	124,611
Noncontrolling Interest in Net Income (Loss) Operating Partnerships, Redeemable	24,248	(5,993)	18,704
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Noncontrolling Interest	201	0	0
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	156,143	1,907	105,907
Preferred stock dividends	(20,739)	(27,245)	(27,245)
Other Preferred Stock Dividends and Adjustments	(12,495)	0	0
Comprehensive income attributable to common shares	122,909	(25,338)	78,662
Subsidiaries [Member]
Net (loss) income	181,447	(4,086)	124,611
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Foreign currency translation adjustments	(1,257)	0	0
Comprehensive Income (Loss)	180,190	(4,086)	124,611
Preferred stock dividends	(20,739)	(27,245)	(27,245)
Other Preferred Stock Dividends and Adjustments	(12,495)	0	0
Comprehensive income attributable to common shares	$ 146,956	$ (31,331)	$ 97,366

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	PreferredStock/Units [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Foreign Currency Adjustment Attributable to Parent [Member]	Series C Preferred Stock [Member]	Series C Preferred Stock [Member]PreferredStock/Units [Member]	Series C Preferred Stock [Member]Additional Paid-in Capital [Member]	Series C Preferred Stock [Member]Retained Earnings [Member]
Balance at Dec. 31, 2013	$ 1,252,274	$ 351,250	$ 65	$ 900,959	$ 0
Balance, shares at Dec. 31, 2013	65,205,274
Net income attributable to controlling interests	$ 105,907				105,907
Dividends declared on common stock	(96,866)			(18,204)	(78,662)
Dividends earned on preferred stock	(27,245)				(27,245)
Redemption of operating partnership units	$ 6,100		0	6,100
Redemption of operating partnership units, shares	234,300
Issuance of stock awards	$ 360		0	360
Issuance of stock awards, shares	163,187
Stock Issued During Period, Value, Stock Options Exercised	$ 5,556		1	5,555
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	507,056
Retirement and forfeiture of stock awards	$ (1,193)		0	(1,193)
Retirement and forfeiture of stock awards, shares	(48,013)
Amortization of deferred compensation costs	$ 6,565			6,565
Adjustments to redeemable noncontrolling interests – operating partnership	(136,117)			(136,117)
Balance at Dec. 31, 2014	$ 1,115,341	351,250	66	764,025	0	$ 0
Balance, shares at Dec. 31, 2014	66,061,804
Net income attributable to controlling interests	$ 1,907				1,907
Dividends declared on common stock	(113,450)			(58,917)	(54,533)
Dividends earned on preferred stock	(27,245)				(27,245)
Redemption of operating partnership units	$ 9,544		0	9,544
Redemption of operating partnership units, shares	363,674
Common stock repurchases	$ (31,912)		(1)	(31,911)
Common stock repurchase, shares	(1,002,610)
Issuance of stock awards	$ 2,239		1	2,238
Issuance of stock awards, shares	565,162
Stock Issued During Period, Value, Stock Options Exercised	$ 7,930		0	7,930
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	362,642
Retirement and forfeiture of stock awards	$ (7,682)		0	(7,682)
Retirement and forfeiture of stock awards, shares	(245,022)
Amortization of deferred compensation costs	$ 7,846			7,846
Adjustments to redeemable noncontrolling interests – operating partnership	(8,105)			(8,105)
Balance at Dec. 31, 2015	956,413	351,250	66	685,042	(79,945)	0
Cumulative Effect of New Accounting Principle in Period of Adoption	$ 0			74	(74)
Balance, shares at Dec. 31, 2015	66,105,650
Net income attributable to controlling interests	$ 157,199				157,199
Other comprehensive loss attributable to controlling interests - foreign currency translation adjustments	(1,056)					(1,056)
Stock Issued During Period, Value, New Issues	$ (275,470)		(8)	(275,462)			$ (194,252)	$ (201,250)	$ (6,998)
Stock Issued During Period, Shares, New Issues	7,613,000
Dividends declared on common stock	$ (143,945)			(99,925)	(44,020)
Dividends earned on preferred stock	(20,739)				(20,739)
Redemption of operating partnership units	$ 64,169		2	64,167
Redemption of operating partnership units, shares	1,618,048
Stock Redeemed or Called During Period, Value	$ (351,250)	(351,250)		(12,495)	(12,495)
Issuance of stock awards	$ 810			810
Issuance of stock awards, shares	227,430
Stock Issued During Period, Value, Stock Options Exercised	$ 10,592			10,592
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	478,733
Retirement and forfeiture of stock awards	$ (2,969)			(2,969)
Retirement and forfeiture of stock awards, shares	(128,098)
Amortization of deferred compensation costs	$ 6,813			6,813
Adjustments to redeemable noncontrolling interests – operating partnership	(178,757)			(178,757)
Balance at Dec. 31, 2016	$ 967,002	$ 201,250	$ 76	$ 766,732	$ 0	$ (1,056)
Balance, shares at Dec. 31, 2016	75,914,763

Consolidated Statement of Partn

Consolidated Statement of Partners' Capital - USD ($) $ in Thousands	Total	Subsidiaries [Member]	Subsidiaries [Member]Limited Partners' Capital - Preferred [Member]	Subsidiaries [Member]Limited Partners' Capital - Common [Member]	Subsidiaries [Member]General Partner's Capital [Member]	Common Stock [Member]	Common Stock [Member]Subsidiaries [Member]	Common Stock [Member]Subsidiaries [Member]Limited Partners' Capital - Common [Member]	PreferredStock/Units [Member]	PreferredStock/Units [Member]Subsidiaries [Member]	PreferredStock/Units [Member]Subsidiaries [Member]Limited Partners' Capital - Preferred [Member]	PreferredStock/Units [Member]Subsidiaries [Member]Limited Partners' Capital - Common [Member]
Balance at Dec. 31, 2013		$ 1,248,055	$ 351,250	$ 887,695	$ 9,110
Balance, units at Dec. 31, 2013				64,542,901	662,373
Net (loss) income	$ 124,611	124,611		$ 123,362	$ 1,249
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustments	$ 0	0
Common unit distributions		(119,697)		(118,723)	(974)
Preferred unit distributions		$ (27,245)		$ (26,972)	(273)
Issuance of OP units to DFT when redeemable partnership units redeemed, units	234,300	234,300		234,300
Redemption of operating partnership units	$ 6,100	$ 6,100		$ 6,100		$ 0
Issuance of OP units for stock awards, units				163,187
Issuance of OP units for stock awards		360		$ 360
Issuance of OP units due to option exercises, units				507,056
Issuance of OP units due to option exercises		5,556		$ 5,556
Retirement and forfeiture of OP units, units				(48,013)
Retirement and forfeiture of OP units		(1,193)		$ (1,193)
Amortization of deferred compensation costs	6,565	6,565		6,565
Adjustments to redeemable partnership units		(131,989)		(130,496)	(1,493)
Balance at Dec. 31, 2014		1,111,123	351,250	$ 752,254	$ 7,619
Balance, units at Dec. 31, 2014				65,399,431	662,373
Net (loss) income	(4,086)	(4,086)		$ (4,045)	$ (41)
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustments	$ 0	0
Common unit distributions		(139,963)		(138,817)	(1,146)
Preferred unit distributions		$ (27,245)		$ (26,972)	(273)
Issuance of OP units to DFT when redeemable partnership units redeemed, units	363,674	363,674		363,674
Redemption of operating partnership units	$ 9,544	$ 9,544		$ 9,544		0
Retirement of OP units for common stock repurchase, units				(1,002,610)
Retirement of OP units for common stock repurchases		(31,912)		$ (31,912)
Issuance of OP units for stock awards, units				565,162
Issuance of OP units for stock awards		2,239		$ 2,239
Issuance of OP units due to option exercises, units				362,642
Issuance of OP units due to option exercises		7,930		$ 7,930
Retirement and forfeiture of OP units, units				(245,022)
Retirement and forfeiture of OP units		(7,682)		$ (7,682)
Amortization of deferred compensation costs	7,846	7,846		7,846
Adjustments to redeemable partnership units		24,404		24,542	(138)
Balance at Dec. 31, 2015		952,198	351,250	$ 594,927	$ 6,021
Balance, units at Dec. 31, 2015				65,443,277	662,373
Net (loss) income	181,447	181,447		$ 179,864	$ 1,583
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustments	$ (1,257)	(1,257)		(1,246)	(11)
Stock Issued During Period, Shares, New Issues	7,613,000							7,613,000
Stock Issued During Period, Value, New Issues	$ 275,470					8	$ 275,470	$ 275,470		$ 194,252	$ 201,250	$ 6,998
Common unit distributions		(170,668)		(169,403)	(1,265)
Preferred unit distributions		$ (20,739)		$ (20,558)	(181)
Issuance of OP units to DFT when redeemable partnership units redeemed, units	1,618,048	1,618,048		1,618,048
Redemption of operating partnership units	$ 64,169	$ 64,169		$ 64,169		$ 2
Stock Redeemed or Called During Period, Value	351,250	351,250	351,250						$ 351,250
Issuance of OP units for stock awards, units				227,430
Issuance of OP units for stock awards		810		$ 810
Issuance of OP units due to option exercises, units				478,733
Issuance of OP units due to option exercises		10,592		$ 10,592
Retirement and forfeiture of OP units, units				(128,098)
Retirement and forfeiture of OP units		(2,969)		$ (2,969)
Amortization of deferred compensation costs	$ 6,813	6,813		6,813
Adjustments to redeemable partnership units		(176,081)		(176,579)	498
Balance at Dec. 31, 2016		$ 962,787	$ 201,250	$ 754,892	$ 6,645
Balance, units at Dec. 31, 2016				75,252,390	662,373

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flow from operating activities
Net (loss) income	$ 181,447	$ (4,086)	$ 124,611
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation, Depletion and Amortization	107,781	104,044	96,780
Impairment of Long-Lived Assets to be Disposed of	0	122,472	0
Gain (Loss) on Sale of Properties	(22,833)	0	0
Write off of Deferred Debt Issuance Cost	1,232	0	1,701
Straight line rent	(93)	13,424	7,673
Amortization of deferred financing costs	(3,712)	(3,151)	(2,980)
Amortization of lease contracts above and below market value	(411)	(880)	(2,393)
Compensation paid with Company common shares	6,597	9,303	6,191
Changes in operating assets and liabilities
Rents and other receivables	(1,884)	(1,475)	4,561
Deferred costs	(3,892)	(4,233)	(2,552)
Prepaid expenses and other assets	(2,196)	4,901	(5,637)
Accounts payable and accrued liabilities	4,546	5,053	1,395
Accrued interest payable	(229)	1,062	776
Prepaid rents and other liabilities	16,185	2,285	8,427
Net cash provided by operating activities	289,962	255,021	244,513
Cash flow from investing activities
Proceeds from Sale of Property, Plant, and Equipment	123,545	0	0
Investments in real estate – development	(294,764)	(217,339)	(265,374)
Payments to Acquire Real Estate	(53,105)	(8,600)	0
Payments to Acquire Land	(20,168)	0	0
Interest capitalized for real estate under development	10,380	11,564	(9,644)
Improvements to real estate	(4,843)	(3,459)	(1,916)
Additions to non-real estate property	(1,270)	(753)	(316)
Net cash used in investing activities	(260,985)	(241,715)	(277,250)
Line of credit:
Proceeds	135,899	120,000	60,000
Repayments	(85,000)	(180,000)	0
Mortgage notes payable:
Repayments	(3,750)	0	0
Unsecured Term Loan:
Proceeds	0	0	96,000
Unsecured notes payable:
Proceeds	0	248,012	0
Payments of financing costs	(5,866)	(4,740)	(3,829)
Proceeds from Issuance of Common Stock	275,470	0	0
Proceeds from Issuance of Redeemable Preferred Stock	194,252	0	0
Payments for Repurchase of Redeemable Preferred Stock	(351,250)	0	0
Equity compensation (payments) proceeds	7,623	249	4,363
Common stock repurchases	0	(31,912)	0
Dividends and distributions:
Common shares	(137,076)	(110,126)	(85,422)
Preferred shares	(24,824)	(27,245)	(27,245)
Redeemable noncontrolling interests – operating partnership	(27,061)	(25,912)	(20,265)
Net cash provided by financing activities	(21,583)	(11,674)	23,602
Net increase (decrease) in cash and cash equivalents	7,394	1,632	(9,135)
Cash and cash equivalents, beginning	31,230	29,598	38,733
Cash and cash equivalents, ending	38,624	31,230	29,598
Supplemental information:
Cash paid for interest	48,871	39,509	32,923
Deferred financing costs capitalized for real estate under development	629	737	601
Construction costs payable capitalized for real estate under development	56,428	22,043	32,949
Redemption of operating partnership units	64,169	9,544	6,100
Adjustments to redeemable noncontrolling interests – operating partnership	178,757	8,105	136,117
Subsidiaries [Member]
Cash flow from operating activities
Net (loss) income	181,447	(4,086)	124,611
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation, Depletion and Amortization	107,781	104,044	96,780
Impairment of Long-Lived Assets to be Disposed of	0	122,472	0
Gain (Loss) on Sale of Properties	(22,833)	0	0
Write off of Deferred Debt Issuance Cost	1,232	0	1,701
Straight line rent	(93)	13,424	7,673
Amortization of deferred financing costs	(3,712)	(3,151)	(2,980)
Amortization of lease contracts above and below market value	(411)	(880)	(2,393)
Compensation paid with Company common shares	6,597	9,303	6,191
Changes in operating assets and liabilities
Rents and other receivables	(1,884)	(1,475)	4,561
Deferred costs	(3,892)	(4,233)	(2,552)
Prepaid expenses and other assets	(2,196)	4,901	(5,637)
Accounts payable and accrued liabilities	4,546	5,053	1,396
Accrued interest payable	(229)	1,062	776
Prepaid rents and other liabilities	16,185	2,288	8,427
Net cash provided by operating activities	289,962	255,024	244,514
Cash flow from investing activities
Proceeds from Sale of Property, Plant, and Equipment	123,545	0	0
Investments in real estate – development	(294,764)	(217,339)	(265,374)
Payments to Acquire Real Estate	(53,105)	(8,600)	0
Payments to Acquire Land	(20,168)	0	0
Interest capitalized for real estate under development	(10,380)	(11,564)	(9,644)
Improvements to real estate	(4,843)	(3,459)	(1,916)
Additions to non-real estate property	(1,270)	(753)	(316)
Net cash used in investing activities	(260,985)	(241,715)	(277,250)
Line of credit:
Proceeds	135,899	120,000	60,000
Repayments	(85,000)	(180,000)	0
Mortgage notes payable:
Repayments	(3,750)	0	0
Unsecured Term Loan:
Proceeds	0	0	96,000
Unsecured notes payable:
Proceeds	0	248,012	0
Payments of financing costs	(5,866)	(4,740)	(3,829)
Proceeds from Issuance of Common Stock	275,470	0	0
Proceeds from Issuance of Redeemable Preferred Stock	194,252	0	0
Payments for Repurchase of Redeemable Preferred Stock	(351,250)	0	0
Equity compensation (payments) proceeds	7,623	249	4,363
Common stock repurchases	0	(31,912)	0
Distributions	(188,961)	(163,283)	(132,932)
Dividends and distributions:
Net cash provided by financing activities	(21,583)	(11,674)	23,602
Net increase (decrease) in cash and cash equivalents	7,394	1,635	(9,134)
Cash and cash equivalents, beginning	27,015	25,380	34,514
Cash and cash equivalents, ending	34,409	27,015	25,380
Supplemental information:
Cash paid for interest	48,871	39,509	32,923
Deferred financing costs capitalized for real estate under development	629	737	601
Construction costs payable capitalized for real estate under development	56,428	22,043	32,949
Redemption of operating partnership units	64,169	9,544	6,100
Adjustments to redeemable noncontrolling interests – operating partnership	$ 176,081	$ (24,404)	$ 131,989

1. Description of Business

1. Description of Business	12 Months Ended
	Dec. 31, 2016
Description of Business [Abstract]
Nature of Operations [Text Block]	Description of Business DuPont Fabros Technology, Inc. (“DFT”), through its controlling interest in DuPont Fabros Technology, L.P. (the “Operating Partnership” or “OP” and collectively with DFT and their operating subsidiaries, the “Company”), is a fully integrated, self-administered and self-managed company that owns, acquires, develops and operates wholesale data centers. DFT is a real estate investment trust, or REIT, for federal income tax purposes and is the sole general partner of the Operating Partnership, and as of December 31, 2016 , owned 84.9% of the common economic interest in the Operating Partnership, of which 0.9% is held as general partnership units. Unless otherwise indicated or unless the context requires otherwise, all references in this report to “we,” “us,” “our,” “our Company” or “the Company” refer to DFT and the Operating Partnership, collectively. As of December 31, 2016 , we held a fee simple interest in the following properties: • 11 operating data centers – ACC2, ACC3, ACC4, ACC5, ACC6, ACC7, CH1, CH2, SC1 Phases I-II, VA3, and VA4; • Five data center projects under development – ACC9 Phases I and II, CH3 Phase I, SC1 Phase III and TOR1 Phase IA; • One shell of a data center currently under development – ACC10; • Three data center projects available for future development – CH3 Phase II, TOR1 Phase IB and TOR1 Phase II; • Land that may be used to develop four additional data centers – ACC8, ACC11, OR1 and OR2.

2. Significant Accounting Polic

2. Significant Accounting Policies	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Significant Accounting Policies [Text Block]	Significant Accounting Policies Basis of Presentation This report combines the annual reports on Form 10-K for the year ended December 31, 2016 of DuPont Fabros Technology, Inc. and DuPont Fabros Technology, L.P. References to “DFT” mean DuPont Fabros Technology, Inc. and its controlled subsidiaries; and references to the “Operating Partnership” or “OP” mean DuPont Fabros Technology, L.P. and its controlled subsidiaries. We believe combining the annual reports on Form 10-K of DFT and the Operating Partnership into this single report provides the following benefits: • enhances investors’ understanding of DFT and the Operating Partnership by enabling investors to view the business as a whole in the same manner as management views and operates the business; • eliminates duplicative disclosure and provides a more streamlined and readable presentation since a substantial portion of the disclosure in this report applies to both DFT and the Operating Partnership; and • creates time and cost efficiencies through the preparation of one combined report instead of two separate reports. We operate DFT and the Operating Partnership as one business. The management of DFT consists of the same employees as the management of the Operating Partnership. We believe it is important for investors to understand the few differences between DFT and the Operating Partnership in the context of how DFT and the Operating Partnership operate as a consolidated company. DFT is a REIT, whose only material asset is its ownership of OP units of the Operating Partnership. As a result, DFT does not conduct business itself, other than acting as the sole general partner of the Operating Partnership, issuing public equity from time to time and guaranteeing unsecured debt of the Operating Partnership. DFT has not issued any indebtedness, but has guaranteed all of the unsecured debt of the Operating Partnership. The Operating Partnership, through its wholly-owned subsidiaries, holds all the real estate assets of the Company. Except for net proceeds from public equity issuances by DFT, which are contributed to the Operating Partnership in exchange for OP units or preferred units, the Operating Partnership generates all remaining capital required by our business. These sources include the Operating Partnership’s operations, its direct or indirect incurrence of indebtedness, and the issuance of partnership units. As sole general partner with control of the Operating Partnership, DFT consolidates the Operating Partnership for financial reporting purposes. The presentation of stockholders’ equity and partners’ capital are the main areas of difference between the consolidated financial statements of DFT and those of the Operating Partnership. The Operating Partnership’s capital includes preferred units and general and limited common units that are owned by DFT and the other partners. DFT’s stockholders’ equity includes preferred stock, common stock, additional paid in capital, retained earnings and accumulated other comprehensive income (loss). The common limited partnership interests held by the limited partners (other than DFT) in the Operating Partnership are presented as “redeemable partnership units” in the Operating Partnership’s consolidated financial statements and as “redeemable noncontrolling interests-operating partnership” in DFT’s consolidated financial statements. The only difference between the assets and liabilities of DFT and the Operating Partnership as of December 31, 2016 was a $4.2 million bank account held by DFT that is not part of the Operating Partnership. Net income is the same for DFT and the Operating Partnership. The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles, or GAAP. All significant intercompany accounts and transactions have been eliminated in the consolidated financial statements. We have one reportable segment consisting of investments in data centers located in the United States and Canada. All of our properties generate similar types of revenues and expenses related to customer rent and reimbursements and operating expenses. The delivery of our products is consistent across all properties and although services are provided to a range of customers, the types of services provided to them are limited to a few core principles. As such, the properties in our portfolio have similar economic characteristics and the nature of the products and services provided to our customers and the method to distribute such services are consistent throughout the portfolio. Use of Estimates The preparation of financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosures of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates. Property All capital improvements for the income-producing properties are capitalized to individual building components, including interest and real estate taxes incurred during the period of development, and depreciated over their estimated useful lives. Interest is capitalized during the period of development based upon applying the property’s specific borrowing rate to the actual development costs expended up to specific borrowings, if any, and then applying our weighted-average borrowing rate to any residual development costs expended during the construction period. Interest is capitalized until the property has reached substantial completion and is ready for its intended use. Interest costs capitalized totaled $11.0 million , $12.3 million and $10.2 million for the years ended December 31, 2016 , 2015 and 2014 , respectively. We cease interest capitalization when a development is placed in service or temporarily suspended. We capitalize pre-development costs, including internal costs, incurred in pursuit of new development opportunities for which we believe future development is probable. Future development is dependent upon various factors, including zoning and regulatory approval, rental market conditions, construction costs and availability of capital. Pre-development costs incurred for which future development is not yet considered probable are expensed as incurred. In addition, if the status of such a pre-development opportunity changes, making future development no longer probable, any capitalized pre-development costs are written-off with a charge to expense. Furthermore, the revenue from incidental operations received from the current improvements in excess of any incremental costs are recorded as a reduction of total capitalized costs of the development project and not as a part of net income. The capitalization of costs during the development of assets (including interest and related loan fees, property taxes and other direct and indirect costs) begins when development efforts commence and ends when the asset, or a portion of the asset, is substantially complete and ready for its intended use. For the years ended December 31, 2016 , 2015 and 2014 , we capitalized $8.0 million , $7.5 million and $4.5 million , respectively, of internal development and leasing costs on all of our data centers. The fair value of in-place leases consists of the following components, as applicable: (1) the estimated cost to replace the leases, including foregone rents during the period of finding a new customer, foregone recovery of customer pass-through, customer improvements, and other direct costs associated with obtaining a new customer (referred to as tenant origination costs); (2) the estimated leasing commissions associated with obtaining a new customer (referred to as leasing commissions); and (3) the above/below market cash flow of the leases, determined by comparing the projected cash flows of the leases in place to projected cash flows of comparable market-rate leases (referred to as lease intangibles). Tenant origination costs are included in buildings and improvements in our accompanying consolidated balance sheets and are amortized as depreciation expense on a straight-line basis over the average remaining life of the underlying leases. Leasing commissions are classified as deferred costs and are amortized as amortization expense on a straight-line basis over the remaining life of the underlying leases. Lease intangible assets and liabilities are classified as lease contracts above and below market value, respectively, and amortized on a straight-line basis as decreases and increases, respectively, to rental revenue over the remaining life of the underlying leases. Should a customer terminate its lease early, the unamortized portions of leasing commissions and lease intangibles associated with that lease are written off to amortization expense or rental revenue, respectively, as further described below. Depreciation on buildings is generally provided on a straight-line basis over 40 years from the date the buildings were placed in service. Building components are depreciated over the life of the respective improvement ranging from 10 to 40 years from the date the components were placed in service. Personal property is depreciated over three years to seven years . Depreciation expense was $103.5 million , $98.8 million and $92.3 million for the years ended December 31, 2016 , 2015 and 2014 , respectively. Repairs and maintenance costs are expensed as incurred. We review each of our properties for indicators of impairment. Examples of such indicators may include a significant decrease in the market price of the property, a significant adverse change in the extent or manner in which the property is being used in its physical condition, a significant adverse change in legal factors or in the business climate that could affect the value of a property, including an adverse action or assessment by a regulator, an accumulation of costs significantly in excess of the amount originally expected for the development of a property, a history of operating or cash flow losses of the property or a current expectation that, more likely than not, a property will be sold or otherwise disposed of significantly before the end of its previously estimated useful life. When such impairment indicators exist, we review an estimate of the future undiscounted net cash flows expected to result from the real estate investment’s use and eventual disposition and compare that estimate to the carrying value of the property. We assess the recoverability of the carrying value of our assets on a property-by-property basis. We consider factors such as future operating income, trends and prospects, as well as the effects of leasing demand, competition, potential sales proceeds and other factors. If our undiscounted cash flow evaluation indicates that we are unable to recover the carrying value of a real estate investment, an impairment loss is recorded to the extent that the carrying value exceeds the estimated fair value of the property. No impairment losses were recorded for the years ended December 31, 2016 and 2014 . In the fourth quarter of 2015, we identified our NJ1 data center as an asset that fell outside of our strategic focus on wholesale data centers in our targeted markets, and it became evident that we would, more likely than not, sell NJ1 prior to its previously estimated useful life. In connection with that determination, we evaluated the recoverability of the carrying value for NJ1 and determined that its carrying value was no longer recoverable due to reducing its expected holding period. As a result, for the year ended December 31, 2015, we reduced the carrying value of NJ1 to its estimated fair value by recording an impairment charge of $122.5 million . Estimated fair value was determined using a third party appraisal for NJ1 in conjunction with the guidance in ASC 820, which involved the use of Level 3 inputs. The appraisal was based on the income capitalization approach which derives value using the property's potential income and an average market capitalization rate for comparable sales in the market. NJ1 was sold in the second quarter of 2016 at a gain of $22.8 million . We classify a data center property as held-for-sale when it meets the necessary criteria, which include when we commit to and actively embark on a plan to sell the asset, the sale is expected to be completed within one year under terms usual and customary for such sales, and actions required to complete the plan indicate that it is unlikely that significant changes to the plan will be made or that the plan will be withdrawn. Data center properties held-for-sale are carried at the lower of cost or fair value less costs to sell. Accordingly, as of December 31, 2016 and 2015 , we did not have any properties classified as held-for-sale. Cash and Cash Equivalents We consider all demand deposits and money market accounts purchased with a maturity date of three months or less, at the date of purchase, to be cash equivalents. Our account balances at one or more institutions exceed the Federal Deposit Insurance Corporation (“FDIC”) insurance coverage and, as a result, there is a concentration of credit risk related to amounts on deposit in excess of FDIC insurance coverage. We have not experienced any losses and believe that the risk is not significant. Deferred Costs Deferred costs, net in our accompanying consolidated balance sheets include both financing and leasing costs. Financing costs, which represent fees and other costs incurred in obtaining debt, are amortized using the effective-interest rate method, or a method that approximates the effective-interest method, over the term of the loan and are included in amortization of deferred financing costs. Balances of financing costs for our unsecured revolving credit facility (the "Unsecured Credit Facility"), net of accumulated amortization, which are presented within deferred costs, net in our accompanying consolidated balance sheets at December 31, 2016 and 2015 , are as follows (in thousands): December 31, Financing costs presented within deferred costs, net 2016 2015 Financing costs $ 12,352 $ 8,198 Accumulated amortization (6,376 ) (4,969 ) Financing costs, net $ 5,976 $ 3,229 Balances of financing costs for our other recognized debt liabilities, net of accumulated amortization, which are presented as a reduction of each of the respective recognized debt liabilities in our accompanying consolidated balance sheets at December 31, 2016 and 2015 , are as follows (in thousands): December 31, Financing costs presented as a reduction of debt liability balances 2016 2015 Financing costs $ 20,423 $ 20,531 Accumulated amortization (7,935 ) (5,618 ) Financing costs, net $ 12,488 $ 14,913 On July 25, 2016, we amended and restated the Unsecured Credit Facility and the Unsecured Term Loan, which, due to the change in composition of lenders comprising the Unsecured Credit Facility's bank group, resulted in a loss on early extinguishment of debt of $1.2 million in the third quarter of 2016, which included a partial write-off of unamortized deferred financing costs of $0.5 million . In May 2014, we amended the Unsecured Credit Facility, which, due to the change in composition of lenders comprising the Unsecured Credit Facility's bank group, resulted in the partial write-off of unamortized deferred financing costs totaling $0.3 million . In July 2014, we amended the Unsecured Term Loan, which, due to the change in composition of lenders comprising the Unsecured Term Loan's bank group, resulted in a loss on early extinguishment of debt of $1.4 million , which included a partial write-off of unamortized deferred financing costs of $0.7 million . Leasing costs, which consist of external fees and costs incurred in the successful negotiation of leases, internal costs expended in the successful negotiation of leases and the estimated leasing commissions resulting from the allocation of the purchase price of ACC2, VA3, VA4 and ACC4, are deferred and amortized over the terms of the applicable leases on a straight-line basis. If an applicable lease terminates prior to the expiration of its initial term, the carrying amount of the leasing costs are written off to amortization expense. In June 2015, we wrote off $0.7 million of unamortized leasing costs to amortization expense related to a former customer in bankruptcy whose leases with us were rejected effective July 1, 2015 pursuant to an order made by the bankruptcy court, described below. Leasing costs incurred for the years ended December 31, 2016 , 2015 and 2014 are as follows (in thousands): Year ended December 31, 2016 2015 2014 Costs incurred for new leases $ 3,690 $ 2,096 $ 2,004 Costs incurred for renewals 202 1,188 153 Costs incurred for re-leases — 949 2,000 Total leasing costs incurred $ 3,892 $ 4,233 $ 4,157 Amortization of deferred leasing costs totaled $4.2 million , $4.9 million and $4.1 million for the years ended December 31, 2016 , 2015 and 2014 , respectively. Balances, net of accumulated amortization, at December 31, 2016 and 2015 are as follows (in thousands): December 31, 2016 2015 Leasing costs $ 53,556 $ 50,503 Accumulated amortization (33,756 ) (29,958 ) Leasing costs, net $ 19,800 $ 20,545 Inventory We maintain fuel inventory for our generators, which is recorded at the lower of cost (on a first-in, first-out basis) or market. As of December 31, 2016 and 2015 , the fuel inventory was $4.2 million and $4.5 million , respectively, and is included in prepaid expenses and other assets in the accompanying consolidated balance sheets. Prepaid Rents Prepaid rents, typically prepayment of the following month’s rent, consist of payments received from customers prior to the time the payments are earned and are recognized as revenue in subsequent periods when earned. Rental Income We, as a lessor, have retained substantially all the risks and benefits of ownership and account for our leases as operating leases. For lease agreements that provide for scheduled fixed and determinable rent increases, rental income is recognized on a straight-line basis over the non-cancellable term of the lease, which commences when control of the space and critical power have been provided to the customer. If the lease contains an early termination clause with a penalty payment, we determine the lease termination date by evaluating whether the penalty reasonably assures that the lease will not be terminated early. Straight-line rents receivable are included in deferred rent, net in the accompanying consolidated balance sheets. Lease inducements, which include cash payments to customers, are amortized as a reduction of rental income over the noncancellable lease term. Lease inducements are included in prepaid expenses and other assets in the accompanying consolidated balance sheets. Lease intangible assets and liabilities that have resulted from above market and below market leases that were acquired are amortized on a straight-line basis as decreases and increases, respectively, to rental revenue over the remaining non-cancellable term of the underlying leases. If a lease terminates prior to the expiration of its initial term, the unamortized portion of straight-line rents receivable, lease inducements and lease intangibles associated with that lease will be written off to rental revenue. In June 2015, we wrote-off as a reduction of base rent $0.4 million of unreserved straight-line rents receivable, $0.1 million of unamortized lease inducements and $1.0 million of unamortized lease intangibles related to a former customer in bankruptcy whose leases with us were rejected effective July 1, 2015 pursuant to an order made by the bankruptcy court. Balances, net of accumulated amortization, at December 31, 2016 and 2015 are as follows (in thousands): December 31, 2016 2015 Lease contracts above market value $ 20,500 $ 20,500 Accumulated amortization (15,362 ) (14,471 ) Lease contracts above market value, net $ 5,138 $ 6,029 Lease contracts below market value $ 24,175 $ 24,175 Accumulated amortization (21,345 ) (20,043 ) Lease contracts below market value, net $ 2,830 $ 4,132 Our policy is to record an allowance for losses on accounts receivable equal to the estimated uncollectible accounts. The estimate is based on our historical experience and a review of the current status of our receivables. As of December 31, 2016 , we had a note receivable from a former customer of $25.0 million , which resulted from the settlement of our claim in this former customer's bankruptcy proceedings in the fourth quarter of 2016 and replaced the $6.5 million note receivable that we had from this former customer as of December 31, 2015 . We are accounting for the note receivable on a non-accrual basis. As of December 31, 2016 and 2015 , we had allowances against these notes of $23.6 million and $5.1 million , respectively, leaving a note receivable, net, of $1.4 million as of December 31, 2016 and 2015 , which is included within rents and other receivables, net in our accompanying consolidated balance sheets. Based on the principal payment schedule in the note that includes semiannual principal payments beginning in June 2017, we continue to be reasonably assured that we will be able to collect the balance of the note receivable, net. We also establish an appropriate allowance for doubtful accounts for receivables arising from the straight-lining of rents. These receivables arise from revenue recognized in excess of amounts currently due under the lease and are recorded as deferred rent in the accompanying consolidated balance sheets. As of December 31, 2016 and 2015 , we had no material allowances. Our customer leases generally contain provisions under which the customers reimburse us for a portion of operating expenses and real estate taxes incurred by the property. Recoveries from tenants are included in revenue in the accompanying consolidated statements of operations in the period the applicable expenditures are incurred. The majority of our customer leases also provide us with a property management fee based on a percentage of base rent collected and property-level operating expenses, other than charges for power used by customers to run their servers and cool their space. Property management fees are included in base rent in the accompanying consolidated statements of operations in the applicable period in which they are earned. Other Revenue Other revenue primarily consists of services provided to customers on a non-recurring basis. This includes layout design and installation of electrical power circuits, data cabling, server cabinets and racks, computer room airflow analyses and monitoring and other services requested by customers. Revenue is recognized on a completed contract basis when the project is finished and ready for the customer's use. This method is consistently applied for all periods presented. Costs of providing these services are included in other expenses in the accompanying consolidated statements of operations. Income Taxes DFT elected to be taxed as a REIT under the Internal Revenue Code of 1986, as amended (the “Code”), commencing with the taxable year ended December 31, 2007. In general, a REIT that meets certain organizational and operational requirements and distributes at least 90 percent of its REIT taxable income to its shareholders in a year will not be subject to income tax to the extent of the income it distributes. We currently qualify and intend to continue to qualify as a REIT under the Code. As a result, no provision for federal income taxes on income from continuing operations is required, except for taxes on certain property sales and on income, if any, of DF Technical Services, LLC, our taxable REIT subsidiary (“TRS”). If we fail to qualify as a REIT in any taxable year, we will be subject to federal income tax (including any applicable alternative minimum tax) on our income at regular corporate tax rates for the year in which we do not qualify and the succeeding four years. Although we expect to qualify for taxation as a REIT, we may be subject to state and local income and franchise taxes and to federal income and excise taxes on any undistributed income. As of December 31, 2016 and 2015 , we did not have any unrecognized tax benefits. We do not believe that there will be any material changes in our unrecognized tax positions over the next 12 months. We are subject to examination by the respective taxing authorities for the tax years 2013 through 2016. In general, a TRS may perform non-customary services for customers, hold assets that DFT cannot hold directly and generally may engage in any real estate or non real estate-related business. A TRS is subject to corporate federal and state income taxes on its taxable income at regular statutory tax rates. For the years ended December 31, 2016 and 2014, we incurred $0.1 million of income taxes. For the year ended December 31, 2015, we incurred no income taxes; however, we recorded a deferred income tax credit of $0.2 million to reverse the cumulative deferred tax expense recorded as of December 31, 2014. We account for income taxes using the asset and liability method under which deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Valuation allowances are provided if, based upon the weight of the available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. As of December 31, 2016 , our TRS had a deferred tax asset of $0.2 million , comprised entirely of its net operating loss carryforward, and no deferred tax liability, resulting in a net deferred tax asset of $0.2 million . We recorded a full valuation allowance for this net deferred tax asset as of December 31, 2016 due to the uncertainty of the realizability of this asset. The net operating loss carryforward of $0.2 million will begin to expire in 2031 if not utilized by then. As of December 31, 2015 , our TRS had a deferred tax asset of $4.6 million , comprised entirely of its net operating loss carryforward, and a deferred tax liability of $2.3 million , primarily comprised of a temporary depreciation difference, resulting in a net deferred tax asset of $2.3 million . We recorded a full valuation allowance for this net deferred tax asset as of December 31, 2015 due to the uncertainty of the realizability of this asset. Redeemable Noncontrolling Interests – Operating Partnership / Redeemable Partnership Units Redeemable noncontrolling interests – operating partnership, as presented on DFT’s consolidated balance sheets, represent the limited partnership interests in the Operating Partnership (the “OP units”) held by individuals and entities other than DFT. These interests are also presented on the Operating Partnership’s consolidated balance sheets, referred to as “redeemable partnership units.” Accordingly, the following discussion related to redeemable noncontrolling interests – operating partnership of DFT refers equally to redeemable partnership units of the Operating Partnership. Redeemable noncontrolling interests – operating partnership, which require cash payment, or allow settlement in shares, but with the ability to deliver the shares outside of the control of DFT, are reported outside of the permanent equity section of the consolidated balance sheets of DFT and the Operating Partnership. Redeemable noncontrolling interests – operating partnership are adjusted for income, losses and distributions allocated to OP units not held by DFT (normal noncontrolling interest accounting amount). Adjustments to redeemable noncontrolling interests – operating partnership are recorded to reflect increases or decreases in the ownership of the Operating Partnership by holders of OP units, including the redemptions of OP units for cash or in exchange for shares of DFT’s common stock. If such adjustments result in redeemable noncontrolling interests – operating partnership being recorded at less than the redemption value of the OP units, redeemable noncontrolling interests – operating partnership are further adjusted to their redemption value. See Note 9. Redeemable noncontrolling interests – operating partnership are recorded at the greater of the normal noncontrolling interest accounting amount or redemption value. The following is a summary of activity for redeemable noncontrolling interests – operating partnership for the years ended December 31, 2016 , 2015 and 2014 (dollars in thousands): OP Units Number Amount Balance at December 31, 2013 15,671,537 $ 387,244 Net income attributable to redeemable noncontrolling interests – operating partnership — 18,704 Distributions declared — (22,831 ) Redemption of operating partnership units (234,300 ) (6,100 ) Adjustments to redeemable noncontrolling interests – operating partnership — 136,117 Balance at December 31, 2014 15,437,237 $ 513,134 Net loss attributable to redeemable noncontrolling interests – operating partnership — (5,993 ) Distributions declared — (26,513 ) Redemption of operating partnership units (363,674 ) (9,544 ) Adjustments to redeemable noncontrolling interests – operating partnership — 8,105 Balance at December 31, 2015 15,073,563 $ 479,189 Net income attributable to redeemable noncontrolling interests – operating partnership — 24,248 Other comprehensive loss attributable to redeemable noncontrolling interests – operating partnership — (201 ) Distributions declared — (26,723 ) Redemption of operating partnership units (1,618,048 ) (64,169 ) Adjustments to redeemable noncontrolling interests – operating partnership — 178,757 Balance at December 31, 2016 13,455,515 $ 591,101 The following is a summary of activity for redeemable partnership units for the years ended December 31, 2016 , 2015 and 2014 (dollars in thousands): OP Units Number Amount Balance at December 31, 2013 15,671,537 $ 387,244 Redemption of operating partnership units (234,300 ) (6,100 ) Adjustments to redeemable partnership units — 131,990 Balance at December 31, 2014 15,437,237 $ 513,134 Redemption of operating partnership units (363,674 ) (9,544 ) Adjustments to redeemable partnership units — (24,401 ) Balance at December 31, 2015 15,073,563 $ 479,189 Redemption of operating partnership units (1,618,048 ) (64,169 ) Adjustments to redeemable partnership units — 176,081 Balance at December 31, 2016 13,455,515 $ 591,101 Net income is allocated to controlling interests and redeemable noncontrolling interests – operating partnership in accordance with the limited partnership agreement of the Operating Partnership. The following is a summary of net income attributable to controlling interests and transfers to redeemable noncontrolling interests – operating partnership for the years ended December 31, 2016 , 2015 and 2014 (dollars in thousands): Year ended December 31, 2016 2015 2014 Net income attributable to controlling interests $ 157,199 $ 1,907 $ 105,907 Transfers from noncontrolling interests: Net change in the Company’s common stock and additional paid in capital due to the redemption of OP units and other adjustments to redeemable noncontrolling interests – operating partnership (114,588 ) 1,439 (130,017 ) $ 42,611 $ 3,346 $ (24,110 ) Earnings Per Share of DFT Basic earnings per share is calculated by dividing the net income attributable to common shares for the period by the weighted average number of common shares outstanding during the period using the two class method. Diluted earnings per share is calculated by dividing the net income attributable to common shares for the period by the weighted average number of common and dilutive securities outstanding during the period using the two class method. Earnings Per Unit of the Operating Partnership Basic earnings per unit is calculated by dividing the net income attributable to common units for the period by the weighted average number of common units outstanding during the period using the two class method. Diluted earnings per unit is calculated by dividing the net income attributable to common units for the period by the weighted average number of common and dilutive securities outstanding during the period using the two class method. Stock-based Compensation We periodically award stock-based compensation to employees and members of our Board of Directors in the form of common stock, restricted common stock, options and performance units. For each comm

3. Real Estate Assets

3. Real Estate Assets	12 Months Ended
	Dec. 31, 2016
Real Estate [Abstract]
Real Estate Disclosure [Text Block]	Real Estate Assets The following is a summary of our properties as of December 31, 2016 (dollars in thousands): Property Location Land Buildings and Improvements Construction in Progress and Land Held for Development Total Cost (2) ACC2 Ashburn, VA $ 2,500 $ 156,480 $ 158,980 ACC3 Ashburn, VA 1,071 96,080 97,151 ACC4 Ashburn, VA 6,600 538,869 545,469 ACC5 Ashburn, VA 6,443 299,016 305,459 ACC6 Ashburn, VA 5,518 216,829 222,347 ACC7 Ashburn, VA 9,753 332,970 342,723 CH1 Elk Grove Village, IL 23,611 359,171 382,782 CH2 Elk Grove Village, IL 14,392 256,539 270,931 SC1 Phases I-II Santa Clara, CA 20,202 433,099 453,301 VA3 Reston, VA 9,000 179,694 188,694 VA4 Bristow, VA 6,800 149,614 156,414 105,890 3,018,361 — 3,124,251 Construction in progress and land held for development (1) 330,983 330,983 $ 105,890 $ 3,018,361 $ 330,983 $ 3,455,234 (1) Properties located in Ashburn, VA (ACC8, ACC9, ACC10, and ACC11), Elk Grove Village, IL (CH3), Santa Clara, CA (SC1 Phase III, formerly referred to as SC2), Hillsboro, OR (OR1 and OR2) and Vaughan, ON (TOR1). (2) As of December 31, 2016, the total cost of long-lived assets located in the United States totaled $3,408.9 million , and the total costs of long-lived assets located in Canada totaled $46.3 million (TOR1 in Vaughan, ON). In February 2016, we acquired two parcels of undeveloped land in Ashburn, Virginia from entities controlled by our Chairman of the Board . One parcel is a 35.4 acre site that we purchased for $15.6 million , which we are using for the development of our ACC9 and ACC10 data center facilities. T he other parcel is an 8.6 acre site that we purchased for $4.6 million . This parcel is being held for the future development of either a powered base shell or build-to-suit data center to be known as ACC11. In June 2016, we completed the sale of our NJ1 data center for a gross purchase price of $125.0 million , and recorded a gain on sale of $22.8 million . We had previously recorded an impairment charge of $122.5 million during the fourth quarter of 2015. In July 2016, we completed the acquisition of a 46.7 acre parcel of land in Hillsboro, Oregon for a purchase price of $11.2 million . This acquisition was treated as an asset purchase under GAAP. We are holding this parcel of land for future development in connection with our expansion plans. In September 2016, we completed the acquisition of a shell building and associated land in Vaughan, Ontario for a purchase price of $54.3 million CAD ( $41.6 million USD). This acquisition was treated as an asset purchase under GAAP. We are currently developing Phase I of TOR1 in this shell. The following presents the major components of our properties and the useful lives over which they are depreciated: Component Component Life (years) Land N/A Building improvements 40 Electrical infrastructure—power distribution units 20 Electrical infrastructure—uninterrupted power supply 25 Electrical infrastructure—switchgear/transformers 30 Fire protection 40 Security systems 20 Mechanical infrastructure—heating, ventilating and air conditioning 20 Mechanical infrastructure—chiller pumps/building automation 25 Mechanical infrastructure—chilled water storage and pipes 30

4. Intangible Assets and Liabil

4. Intangible Assets and Liabilities (Notes)	12 Months Ended
	Dec. 31, 2016
Intangible Assets and Liabilities [Abstract]
Intangible Assets And Liabilities [Text Block]	Intangible Assets and Liabilities Leasing costs are classified as deferred costs and are amortized as amortization expense on a straight-line basis over the remaining life of the underlying leases. As of December 31, 2016 , these assets have a weighted average remaining life of 6.9 years with estimated future amortization as follows (in thousands): Year Ending December 31, 2017 $ 4,200 2018 3,854 2019 2,778 2020 2,235 2021 1,752 2022 and thereafter 4,981 $ 19,800 Lease intangible assets and liabilities are classified as lease contracts above and below market value, respectively, and amortized on a straight-line basis as decreases and increases, respectively, to rental revenue over the remaining term of the underlying leases. As of December 31, 2016 , our net lease intangible assets have a weighted average remaining life of 6.9 years for above market leases and 3.5 years for below market leases with estimated net future amortization (as an increase (decrease) to rental income) as follows (in thousands): Year Ending December 31, 2017 $ 467 2018 35 2019 (480 ) 2020 (644 ) 2021 (570 ) 2022 and thereafter (1,116 ) $ (2,308 ) Tenant origination costs are included in buildings and improvements in our accompanying consolidated balance sheets and are amortized as depreciation expense on a straight-line basis over the average remaining life of the underlying leases. As of December 31, 2016 , these assets have a weighted average remaining life of 1.6 years with estimated future amortization as follows (in thousands): Year Ending December 31, 2017 $ 1,243 2018 746 $ 1,989

5. Leases (Notes)

5. Leases (Notes)	12 Months Ended
	Dec. 31, 2016
Leases [Abstract]
Leases of Lessor Disclosure [Text Block]	Leases For the years ended December 31, 2016 , 2015 and 2014 , the following customers comprised more than 10.0% of our consolidated revenues: Microsoft Facebook Fortune 25 Investment Grade-Rated Company Year ended December 31, 2016 29.7 % 17.6 % 10.3 % Year ended December 31, 2015 25.2 % 16.9 % 6.5 % Year ended December 31, 2014 21.6 % 17.4 % 4.7 % As of December 31, 2016 , these three customers accounted for $(2.0) million , $38.5 million and $11.7 million of deferred rent and $13.5 million , $8.4 million and $5.2 million of prepaid rents, respectively. As of December 31, 2015 , these three customers accounted for $(5.2) million , $42.5 million , and $8.5 million of deferred rent and $9.8 million , $6.8 million , and $3.2 million of prepaid rents, respectively. We do not hold security deposits from these customers. The majority of our customers operate within the technology industry and, as such, their viability is subject to market fluctuations in that industry. As of December 31, 2016 , future minimum lease payments to be received under noncancellable operating leases are as follows for the years ending December 31 (in thousands): 2017 $ 365,642 2018 358,439 2019 292,355 2020 239,842 2021 219,023 2022 and thereafter 751,080 $ 2,226,381

6. Debt

6. Debt	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Debt Disclosure [Text Block]	Debt Debt Summary as of December 31, 2016 and December 31, 2015 ($ in thousands) December 31, 2016 December 31, 2015 Amounts (1) % of Total Rates Maturities (years) Amounts (1) Secured $ 111,250 9 % 2.3 % 1.2 $ 115,000 Unsecured 1,150,926 91 % 4.9 % 5.1 1,100,000 Total $ 1,262,176 100 % 4.7 % 4.8 $ 1,215,000 Fixed Rate Debt: Unsecured Notes due 2021 $ 600,000 47 % 5.9 % 4.7 $ 600,000 Unsecured Notes due 2023 (2) 250,000 20 % 5.6 % 6.5 250,000 Fixed Rate Debt $ 850,000 67 % 5.8 % 5.2 $ 850,000 Floating Rate Debt: Unsecured Credit Facility 50,926 4 % 2.4 % 3.6 — Unsecured Term Loan 250,000 20 % 2.3 % 5.1 250,000 ACC3 Term Loan 111,250 9 % 2.3 % 1.2 115,000 Floating Rate Debt 412,176 33 % 2.3 % 3.8 365,000 Total $ 1,262,176 100 % 4.7 % 4.8 $ 1,215,000 (1) Principal amounts exclude deferred financing costs. (2) Principal amount shown excludes original issue discount of $1.7 million . Outstanding Indebtedness Unsecured Credit Facility and Unsecured Term Loan On July 25, 2016, we entered into an amended and restated credit agreement with a syndicate of banks (the "Amended and Restated Credit Agreement") that includes the following: • an unsecured revolving credit facility with a total commitment of $750 million (the "Unsecured Credit Facility"); and • an unsecured term loan facility, which has a total commitment and amount outstanding of $250 million (the "Unsecured Term Loan"). In November 2016, we added a Canadian dollar sublimit of up to $185 million (approximately CAD $250 million ) to the Unsecured Credit Facility, which allows us to borrow in Canadian dollars to fund our TOR1 data center development in Vaughan, Ontario. In addition, the Canadian borrowings allow us to hedge our foreign currency investment risk by having these liabilities translate at the same exchange rates as our Canadian assets at the end of each period. In 2016, we designated all of the Canadian borrowings on our Unsecured Credit Facility, which totaled CAD $62.0 million as of December 31, 2016 , as a net investment hedge of our Canadian assets. For the effective portion of these net investment hedges, the currency translation effects of these borrowings are reflected in accumulated other comprehensive loss within shareholders' equity on our consolidated balance sheets, where they offset the currency translation effects of our investment in our Canadian assets. There was no ineffectiveness for our net investment hedges during 2016. At our option, we may increase the total commitment under the Unsecured Credit Facility and the Unsecured Term Loan to $1.25 billion , if one or more lenders commit to being a lender for the additional amount and certain other customary conditions are met. Prior to July 25, 2016, the Unsecured Credit Facility and the Unsecured Term Loan were outstanding under separate credit agreements. The obligations under the Amended and Restated Credit Agreement are unconditionally guaranteed, jointly and severally, on a senior unsecured basis by DFT and all of the Operating Partnership’s subsidiaries that currently guaranty the obligations under the Unsecured Notes due 2021, listed below. Prior to July 25, 2016, the separate credit agreements that governed the Unsecured Credit Facility and the Unsecured Term Loan provided for substantially the same guarantees as the Amended and Restated Credit Agreement. We may prepay the Unsecured Credit Facility and the Unsecured Term Loan at any time, in whole or in part, without penalty or premium. The Amended and Restated Credit Agreement requires that DFT, the Operating Partnership and their subsidiaries comply with various covenants, including with respect to restrictions on liens, incurring indebtedness, making investments, effecting mergers and/or asset sales, and certain limits on dividend payments, distributions and purchases of DFT's stock. In addition, the facility imposes financial maintenance covenants relating to, among other things, the following matters: • unsecured debt not exceeding 60% of the value of unencumbered assets, subject to an increase up to 65% following a material acquisition; • net operating income generated from unencumbered properties divided by the amount of unsecured debt (net of unrestricted cash and cash equivalents) being not less than 12.5% , subject to a decrease to not less than 10.0% following a material acquisition; • total indebtedness not exceeding 60% of gross asset value, subject to an increase up to 65% following a material acquisition; • fixed charge coverage ratio being not less than 1.70 to 1.00 ; • tangible net worth being not less than $2.3 billion plus 75% of the sum of (i) net equity offering proceeds after July 25, 2016 (but excluding such net offering proceeds that are used within ninety (90) days following the consummation of the applicable equity offering for permitted equity redemptions) and (ii) the value of equity interests issued in connection with a contribution of assets to the borrower or its subsidiaries; and • until an investment grade unsecured debt credit rating has been achieved, unhedged variable rate debt not exceeding 30% of gross asset value. The Amended and Restated Credit Agreement includes customary events of default, the occurrence of which, following any applicable cure period, would permit the lenders to, among other things, declare the principal, accrued interest and other obligations of the Operating Partnership under the facility to be immediately due and payable. We were in compliance with all covenants under the Unsecured Credit Facility and the Unsecured Term Loan as of December 31, 2016 . The Unsecured Credit Facility matures on July 25, 2020 . We may elect to have borrowings under the Unsecured Credit Facility bear interest at either the London Interbank Offered Rate (“LIBOR”) or a base rate, which is based on the lender's prime rate, in each case plus an applicable margin. Prior to our receiving an investment grade credit rating, the applicable margin added to LIBOR and the base rate is based on the table below. Applicable Margin Pricing Level Ratio of Total Indebtedness to Gross Asset Value LIBOR Rate Loans Base Rate Loans Level 1 Less than or equal to 35% 1.55 % 0.55 % Level 2 Greater than 35% but less than or equal to 40% 1.65 % 0.65 % Level 3 Greater than 40% but less than or equal to 45% 1.80 % 0.80 % Level 4 Greater than 45% but less than or equal to 52.5% 1.95 % 0.95 % Level 5 Greater than 52.5% 2.15 % 1.15 % The applicable margin is currently set at pricing Level 1. The terms of the Unsecured Credit Facility provide for the adjustment of the applicable margin from time to time according to the ratio of the Operating Partnership’s total indebtedness to gross asset value in effect from time to time. In the event we receive an investment grade credit rating, borrowings under the Unsecured Credit Facility will bear interest based on the table below. Applicable Margin Credit Rating Level Credit Rating LIBOR Rate Loans Base Rate Loans Level 1 Greater than or equal to A- by S&P or A3 by Moody’s 0.85 % 0.00 % Level 2 Greater than or equal to BBB+ by S&P or Baa1 by Moody’s 0.90 % 0.00 % Level 3 Greater than or equal to BBB by S&P or Baa2 by Moody’s 1.00 % 0.00 % Level 4 Greater than or equal to BBB- by S&P or Baa3 by Moody’s 1.20 % 0.20 % Level 5 Less than BBB- by S&P or Baa3 by Moody’s 1.55 % 0.55 % Following the receipt of such investment grade rating, the terms of the Unsecured Credit Facility provide for the adjustment of the applicable margin from time to time according to the rating then in effect. The amount available for borrowings under the Unsecured Credit Facility is determined according to a calculation comparing the value of certain unencumbered properties designated by the Operating Partnership at such time relative to the amount of the Operating Partnership's unsecured debt. Up to $35 million of the borrowings under the Unsecured Credit Facility may be used for letters of credit. As of December 31, 2016 , we had no letters of credit outstanding. As of December 31, 2016, we had USD $10.0 million and CAD $55.0 million outstanding on the Unsecured Credit Facility for a total of USD $50.9 million outstanding. As of February 23, 2017 , we had USD $60.0 million and CAD $62.0 million outstanding on the Unsecured Credit Facility for a total of approximately USD $107.1 million outstanding. The Unsecured Term Loan matures on January 21, 2022 . Under the terms of the Unsecured Term Loan, we may elect to have borrowings under the loan bear interest at either LIBOR or a base rate, which is based on the lender's prime rate, in each case plus an applicable margin. Prior to our receiving an investment grade credit rating, the applicable margin added to LIBOR and the base rate is based on the table below. Applicable Margin Pricing Level Ratio of Total Indebtedness to Gross Asset Value LIBOR Rate Loans Base Rate Loans Level 1 Less than or equal to 35% 1.50 % 0.50 % Level 2 Greater than 35% but less than or equal to 40% 1.60 % 0.60 % Level 3 Greater than 40% but less than or equal to 45% 1.75 % 0.75 % Level 4 Greater than 45% but less than or equal to 52.5% 1.90 % 0.90 % Level 5 Greater than 52.5% 2.10 % 1.10 % The applicable margin is currently set at pricing Level 1. The terms of the Unsecured Term Loan also provide that, in the event we receive an investment grade credit rating, borrowings under the loan will bear interest based on the table below. Applicable Margin Credit Rating Level Credit Rating LIBOR Rate Loans Base Rate Loans Level 1 Greater than or equal to A- by S&P or A3 by Moody’s 0.825 % 0.00 % Level 2 Greater than or equal to BBB+ by S&P or Baa1 by Moody’s 0.875 % 0.00 % Level 3 Greater than or equal to BBB by S&P or Baa2 by Moody’s 1.00 % 0.00 % Level 4 Greater than or equal to BBB- by S&P or Baa3 by Moody’s 1.25 % 0.25 % Level 5 Less than BBB- by S&P or Baa3 by Moody’s 1.65 % 0.65 % Following the receipt of such investment grade rating, the terms of the loan provide for the adjustment of the applicable margin from time to time according to the rating then in effect. ACC3 Term Loan We have a $111.3 million term loan facility that is secured by our ACC3 data center facility and an assignment of the lease agreement between us and the customer of ACC3 (the "ACC3 Term Loan"). The borrower, one of our subsidiaries, may elect to have borrowings under the ACC3 Term Loan bear interest at (i) LIBOR plus 1.55% or (ii) a base rate, which is based on the lender's prime rate, plus 0.55% . The interest rate is currently at LIBOR plus 1.55% . The ACC3 Term Loan matures on March 27, 2018 , and we may prepay the ACC3 Term Loan at any time, in whole or in part, without penalty or premium. The Operating Partnership has guaranteed the outstanding principal amount of the ACC3 Term Loan, plus interest and certain costs under the loan. The ACC3 Term Loan imposes financial maintenance covenants relating to, among other things, the following matters: • consolidated total indebtedness of the Operating Partnership not exceeding 60% of gross asset value of the Operating Partnership; • fixed charge coverage ratio of the Operating Partnership being not less than 1.70 to 1.00 ; • tangible net worth of the Operating Partnership being not less than $1.3 billion plus 80% of the sum of (i) net equity offering proceeds and (ii) the value of equity interests issued in connection with a contribution of assets to the Operating Partnership or its subsidiaries; and • debt service coverage ratio of the borrower not less than 1.50 to 1.00 . We were in compliance with all of the covenants under the ACC3 Term Loan as of December 31, 2016 . Unsecured Notes due 2021 On September 24, 2013 , the Operating Partnership completed the sale of $600 million of 5.875% senior unsecured notes due 2021, which we refer to as the Unsecured Notes due 2021. The Unsecured Notes due 2021 were issued at face value and mature on September 15, 2021 . We pay interest on the Unsecured Notes due 2021 semi-annually, in arrears, on March 15th and September 15th of each year. The Unsecured Notes due 2021 are unconditionally guaranteed, jointly and severally, on a senior unsecured basis by DFT and certain of the Operating Partnership’s subsidiaries, including the subsidiaries that own the ACC2, ACC4, ACC5, ACC6, VA3, VA4, CH1 and SC1 data centers (collectively, the “Subsidiary Guarantors”), but excluding the subsidiaries that own the ACC3, ACC7, ACC9, ACC10, CH2, CH3 and TOR1 data centers, the ACC8, ACC11, OR1 and OR2 parcels of land, our taxable REIT subsidiary, DF Technical Services LLC and our property management subsidiary, DF Property Management LLC. The Unsecured Notes due 2021 rank (i) equally in right of payment with all of the Operating Partnership's existing and future senior unsecured indebtedness, (ii) senior in right of payment with all of its existing and future subordinated indebtedness, (iii) effectively subordinate to any of the Operating Partnership's existing and future secured indebtedness and (iv) effectively junior to any liabilities of any subsidiaries of the Operating Partnership that do not guarantee the Unsecured Notes due 2021. The guarantees of the Unsecured Notes due 2021 by DFT and the Subsidiary Guarantors rank (i) equally in right of payment with such guarantor's existing and future senior unsecured indebtedness, (ii) senior in right of payment with all of such guarantor's existing and future subordinated indebtedness and (iii) effectively subordinate to any of such guarantor's existing and future secured indebtedness The Unsecured Notes due 2021 may be redeemed at the Operating Partnership's option, in whole or in part, at any time, at the following redemption prices (expressed as percentages of the principal amount thereof) if redeemed during the 12-month period commencing September 15 of the years indicated below, in each case together with accrued and unpaid interest to the date of redemption: Year Redemption Price 2016 104.406 % 2017 102.938 % 2018 101.469 % 2019 and thereafter 100.000 % If there is a change of control (as defined in the indenture governing the Unsecured Notes due 2021) of the Operating Partnership or DFT, we must offer to purchase the Unsecured Notes due 2021 at a price equal to 101% of the principal amount thereof, plus accrued and unpaid interest. In addition, in certain circumstances we may be required to use the net proceeds of asset sales to purchase a portion of the Unsecured Notes due 2021 at 100% of the principal amount thereof, plus accrued and unpaid interest. The Unsecured Notes due 2021 have certain covenants limiting the ability of or prohibiting the Operating Partnership and certain of its subsidiaries from, among other things, (i) incurring secured or unsecured indebtedness, (ii) entering into sale and leaseback transactions, (iii) making certain dividend payments, distributions, purchases of DFT's common stock and investments, (iv) entering into transactions with affiliates, (v) entering into agreements limiting the ability to make certain transfers and other payments from subsidiaries, (vi) engaging in sales of assets or (vii) engaging in certain mergers, consolidations or transfers/sales of all or substantially all assets. However, DFT may pay the minimum dividend necessary to meet its REIT income distribution requirements. The Unsecured Notes due 2021 also require the Operating Partnership and the Subsidiary Guarantors to maintain total unencumbered assets of at least 150% of their unsecured debt on a consolidated basis. The Unsecured Notes due 2021 also have customary events of default, including, but not limited to, nonpayment, breach of covenants, and payment or acceleration defaults in certain other indebtedness of ours or certain of our subsidiaries. Upon an event of default, the holders of the Unsecured Notes due 2021 or the trustee may declare the Unsecured Notes due 2021 due and immediately payable. We were in compliance with all covenants under the Unsecured Notes due 2021 as of December 31, 2016 . Unsecured Notes due 2023 On June 9, 2015 , the Operating Partnership completed the sale of $250 million of 5.625% senior unsecured notes due 2023, which we refer to as the Unsecured Notes due 2023. The Unsecured Notes due 2023 were issued at 99.205% of par and mature on June 15, 2023 . We pay interest on the Unsecured Notes due 2023 semi-annually, in arrears, on June 15th and December 15th of each year. The Unsecured Notes due 2023 are unconditionally guaranteed, jointly and severally, on a senior unsecured basis by DFT and the same Subsidiary Guarantors as those that guarantee the Unsecured Notes due 2021. The ranking of the Unsecured Notes due 2023 and the guarantees of these notes are the same as the ranking of the Unsecured Notes due 2021 and the guarantees of those notes. At any time prior to June 15, 2018, the Operating Partnership may redeem the Unsecured Notes due 2023, in whole or in part, at a price equal to the sum of (i) 100% of the principal amount of the Unsecured Notes due 2023 to be redeemed, plus (ii) a make-whole premium and accrued and unpaid interest. The Unsecured Notes due 2023 may be redeemed at the Operating Partnership's option, in whole or in part, at any time, on and after June 15, 2018 at the following redemption prices (expressed as percentages of the principal amount thereof) if redeemed during the 12-month period commencing June 15 of the years indicated below, in each case together with accrued and unpaid interest to the date of redemption: Year Redemption Price 2018 104.219 % 2019 102.813 % 2020 101.406 % 2021 and thereafter 100.000 % If there is a change of control (as defined in the indenture governing the Unsecured Notes due 2023) of the Operating Partnership or DFT, we must offer to purchase the Unsecured Notes due 2023 at a price equal to 101% of the principal amount thereof, plus accrued and unpaid interest. In addition, in certain circumstances we may be required to use the net proceeds of asset sales to purchase a portion of the Unsecured Notes due 2023 at 100% of the principal amount thereof, plus accrued and unpaid interest. The Unsecured Notes due 2023 have certain covenants limiting or prohibiting the ability of the Operating Partnership and certain of its subsidiaries from, among other things, (i) incurring secured or unsecured indebtedness, (ii) entering into sale and leaseback transactions, (iii) making certain dividend payments, distributions, purchases of DFT's common stock and investments, (iv) entering into transactions with affiliates, (v) entering into agreements limiting the ability to make certain transfers and other payments from subsidiaries, (vi) engaging in sales of assets or (vii) engaging in certain mergers, consolidations or transfers/sales of all or substantially all assets. However, DFT may pay the minimum dividend necessary to meet its REIT income distribution requirements. The Unsecured Notes due 2023 also require the Operating Partnership and the Subsidiary Guarantors to maintain total unencumbered assets of at least 150% of their unsecured debt on a consolidated basis. The Unsecured Notes due 2023 also have customary events of default, including, but not limited to, nonpayment, breach of covenants, and payment or acceleration defaults in certain other indebtedness of ours or certain of our subsidiaries. Upon an event of default, the holders of the Unsecured Notes due 2023 or the trustee may declare the Unsecured Notes due 2023 due and immediately payable. We were in compliance with all covenants under the Unsecured Notes due 2023 as of December 31, 2016 . A summary of our debt repayment schedule as of December 31, 2016 is as follows: Debt Maturity as of December 31, 2016 ($ in thousands) Year Fixed Rate (1) Floating Rate (1) Total (1) % of Total Rates 2017 — 8,750 (4) 8,750 0.7 % 2.3 % 2018 — 102,500 (4) 102,500 8.1 % 2.3 % 2019 — — — — % — % 2020 — 50,926 (5) 50,926 4.1 % 2.4 % 2021 600,000 (2) — 600,000 47.5 % 5.9 % 2022 — 250,000 (6) 250,000 19.8 % 2.3 % 2023 250,000 (3) — 250,000 19.8 % 5.6 % Total $ 850,000 $ 412,176 $ 1,262,176 100 % 4.7 % (1) Principal amounts exclude deferred financing costs. (2) The 5.875% Unsecured Notes due 2021 mature on September 15, 2021 . (3) The 5.625% Unsecured Notes due 2023 mature on June 15, 2023 . Principal amount excludes original issue discount of $1.7 million as of December 31, 2016 . (4) The ACC3 Term Loan matures on March 27, 2018 with no extension option. Quarterly principal payments of $1.25 million began on April 1, 2016 , increase to $2.5 million on April 1, 2017 and continue through maturity. (5) The Unsecured Credit Facility matures on July 25, 2020 with a one-year extension option. (6) The Unsecured Term Loan matures on January 21, 2022 with no extension option.

7. Related Party Transactions (

7. Related Party Transactions (Notes)	12 Months Ended
	Dec. 31, 2016
Related Party Transactions Disclosure [Text Block]	Related Party Transactions We leased space for our headquarters building from an affiliate of our Chairman of the Board and our former CEO. In addition, our Executive Vice President, Chief Development Officer, is a non-managing member of this entity, and her sole interest is an approximately 1% non-managing membership interest. Rent expense was $0.3 million , $0.4 million and $0.4 million for each of the years ended December 31, 2016 , 2015 and 2014 . This lease ended on September 30, 2016 and we have entered into a new office lease with an unrelated party. In February 2016, we acquired two parcels of undeveloped land in Ashburn, Virginia, from entities controlled by our Chairman of the Board. One parcel is a 35.4 acre site that we purchased for $15.6 million , which we are using for the development of our ACC9 and ACC10 data center facilities . The managers of the entity that sold us this site are a limited liability company owned solely by our Chairman of the Board, which also owns approximately 7% of the seller, and a limited liability company owned solely by our former CEO which also owns approximately 1% of the seller. In connection with the purchase of this parcel, the parties agreed that the party who began improvement work first on any portion of the property that is adjacent to the road would be responsible for certain improvements to the road required by the county and that the cost of these improvements would be shared between the parties. We were the first to begin improvements to the land adjacent to the road, and we have begun to make the necessary improvements to the road as required. As of December 31, 2016, $0.3 million was due to us from the seller for its share of these improvement costs. The other parcel is an 8.6 acre site that we purchased for $4.6 million . This parcel is being held for the future development of either a powered base shell or build-to-suit data center to be known as ACC11. Our Chairman of the Board and our former CEO are the managers of the limited liability company that manages the entity that sold us this site. Our Chairman of the Board directly and indirectly owns approximately 23% of the seller, and our former CEO directly and indirectly owns approximately 18% of the seller. In addition, Frederic V. Malek, one of our independent directors, is a non-managing member of the entity that owned this site. Mr. Malek’s sole interest in this entity is the ownership of an approximately 4% non-managing membership interest; he is neither an employee nor an executive officer of this entity. The purchase price for each site was based on an appraisal prepared for the Audit Committee of our Board of Directors by an independent appraisal firm.

8. Commitments and Contingencie

8. Commitments and Contingencies	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies Disclosure [Text Block]	Commitments and Contingencies We are involved from time to time in various legal proceedings, lawsuits, examinations by various tax authorities and claims that have arisen in the ordinary course of business. We currently believe that the resolution of such matters will not have a material adverse effect on our financial condition or results of operations. Contracts related to the development of ACC7 Phase IV, ACC9 Phases I-II, SC1 Phase III, CH3 Phase I and ACC10 data centers were in place as of December 31, 2016 . These contracts are cost-plus in nature whereby the contract sum is the aggregate of the contractor's cost to perform the work and to purchase the equipment plus a contractor fee. Control estimates, which are adjusted from time to time to reflect any contract changes, are estimates of the total contract cost at completion. As of December 31, 2016 , the control estimates were as follows for our projects under development: • ACC7 Phase IV: $33.3 million of which $31.7 million had been incurred, and an additional $0.1 million has been committed under this contract. • ACC9 Phase I: $168.4 million of which $126.9 million has been incurred, and an additional $23.5 million has been committed under this contract. • ACC9 Phase II: $63.9 million of which $5.2 million has been incurred, and an additional $31.0 million has been committed under this contract. • SC1 Phase III: $149.0 million of which $78.6 million has been incurred, and an additional $17.1 million has been committed under this contract. • CH3 Phase I: $190.7 million of which $6.0 million has been incurred, and an additional $35.4 million has been committed under this contract. • ACC10 shell: $52.1 million of which $0.1 million has been incurred, and an additional $2.3 million has been committed under this contract. Concurrent with DFT’s October 2007 initial public offering, we entered into tax protection agreements with some of the contributors of the initial properties including our Chairman of the Board and our former CEO. Pursuant to the terms of these agreements, if we dispose of any interest in the initial contributed properties that generates more than a certain allowable amount of built-in gain for the contributors, as a group, in any single year through 2017, we will indemnify the contributors for a portion of the tax liabilities incurred with respect to the amount of built-in gain and tax liabilities incurred as a result of the reimbursement payment. The amount of initial built-in gain that can be recognized as of January 1, 2017 without triggering the tax protection provisions is approximately 100% of the initial built-in gain of $667 million (unaudited). This percentage has increased each year by 10% , accumulating to 100% in 2017. As of December 31, 2016 , none of the tax protection provisions have been triggered and no liability has been recorded on our consolidated balance sheet. If, as of January 1, 2017, the tax protection provisions were triggered, we would not be liable for protection on the taxes related to the built-in gain. Additionally, pursuant to the terms of these agreements, we must provide an opportunity for certain of the contributors of the initial properties to guarantee a secured loan and, if we fail to do so, we could be liable for protection on the taxes related to approximately $57 million (unaudited) of remaining minimum liability. The amount of our liability for protection on taxes could be based on the highest federal, state and local capital gains tax rates of the applicable contributor. Any sale by the Company that requires payments to any of DFT’s executive officers or directors pursuant to these agreements requires the approval of at least 75% of the disinterested members of DFT’s Board of Directors.

9. Redeemable noncontrolling in

9. Redeemable noncontrolling interests operating partnership / Redeemable partnership units	12 Months Ended
	Dec. 31, 2016
Redeemable noncontrolling interests – operating partnership / Redeemable partnership units [Abstract]
Redeemable noncontrolling interests – operating partnership / Redeemable partnership units [Text Block]	Redeemable noncontrolling interests – operating partnership / Redeemable partnership units Redeemable noncontrolling interests – operating partnership, as presented in DFT’s accompanying consolidated balance sheets, represent the OP units held by individuals and entities other than DFT. These interests are also presented in the Operating Partnership’s consolidated balance sheets, referred to as “redeemable partnership units.” Accordingly, the following discussion related to redeemable noncontrolling interests – operating partnership of DFT refers equally to redeemable partnership units of the Operating Partnership. The redemption value of redeemable noncontrolling interests – operating partnership as of December 31, 2016 and December 31, 2015 was $591.1 million and $479.2 million , respectively, based on the closing share price of DFT’s common stock of $43.93 and $31.79 , respectively, on those dates. Holders of OP units are entitled to receive distributions in a per unit amount equal to the per share dividends made with respect to each share of DFT’s common stock, if and when DFT’s Board of Directors declares such a dividend. Holders of OP units have the right to tender their units for redemption, in an amount equal to the fair market value of DFT’s common stock. DFT may elect to redeem tendered OP units for cash or for shares of DFT’s common stock. During the years ended December 31, 2016 , 2015 and 2014 OP unitholders redeemed a total of 1,618,048 , 363,674 , and 234,300 OP units, respectively, in exchange for an equal number of shares of common stock. See Note 2.

10. Preferred Stock

10. Preferred Stock	12 Months Ended
	Dec. 31, 2016
Preferred Stock [Abstract]
Preferred Stock [Text Block]	Preferred Stock Series A Preferred Stock In October 2010, DFT issued 7,400,000 shares of 7.875% Series A Cumulative Redeemable Perpetual Preferred Stock (the "Series A Preferred Stock"), for $185.0 million in an underwritten public offering. The liquidation preference on the Series A Preferred Stock is $25 per share and dividends are scheduled quarterly. For each share of Series A Preferred Stock issued by DFT, the Operating Partnership issued a preferred unit equivalent to DFT with the same terms. On May 27, 2016 , DFT redeemed 3,400,000 shares of its Series A Preferred Stock at a redemption price of $25 per share, plus accrued and unpaid dividends through the date of redemption. On June 9, 2016 , DFT redeemed the remaining 4,000,000 shares of its Series A Preferred Stock at a redemption price of $25 per share, plus accrued and unpaid dividends through the date of redemption. Accordingly, for the year ended December 31, 2016 , DFT wrote-off the original issuance costs related to the shares of Series A Preferred Stock totaling $6.4 million . For the year ended December 31, 2016 , DFT declared and paid a cash dividend on its Series A Preferred Stock, of which the OP paid an equivalent distribution on its preferred units: Record Date Payment Date Cash Dividend Ordinary Taxable Dividend (Unaudited) Nontaxable Return of Capital Distributions (Unaudited) 4/1/2016 4/15/2016 $ 0.4921875 $ 0.4921875 $ 0.00 $ 0.4921875 $ 0.4921875 $ 0.00 For the year ended December 31, 2015 , DFT declared and paid the following cash dividends on its Series A Preferred Stock, of which the OP paid an equivalent distribution on its preferred units: Record Date Payment Date Cash Dividend Ordinary Taxable Dividend (Unaudited) Nontaxable Return of Capital Distributions (Unaudited) 4/2/2015 4/15/2015 $ 0.4921875 $ 0.4921875 $ 0.00 7/2/2015 7/15/2015 0.4921875 0.4921875 0.00 10/2/2015 10/15/2015 0.4921875 0.4921875 0.00 12/30/2015 1/15/2016 0.4921875 0.4921875 0.00 $ 1.9687500 $ 1.9687500 $ 0.00 For the year ended December 31, 2014 , DFT declared and paid the following cash dividends on its Series A Preferred Stock, of which the OP paid an equivalent distribution on its preferred units: Record Date Payment Date Cash Dividend Ordinary Taxable Dividend (Unaudited) Nontaxable Return of Capital Distributions (Unaudited) 4/4/2014 4/15/2014 $ 0.4921875 $ 0.4921875 $ 0.00 7/3/2014 7/15/2014 0.4921875 0.4921875 0.00 10/3/2014 10/15/2014 0.4921875 0.4921875 0.00 12/30/2014 1/15/2015 0.4921875 0.4921875 0.00 $ 1.9687500 $ 1.9687500 $ 0.00 Series B Preferred Stock In March 2011 and January 2012, DFT issued an aggregate of 6,650,000 shares of 7.625% Series B Cumulative Redeemable Perpetual Preferred Stock (the "Series B Preferred Stock"), for $166.3 million in underwritten public offerings. The liquidation preference on the Series B Preferred Stock is $25 per share and dividends are scheduled quarterly. For each share of Series B Preferred Stock issued by DFT, the Operating Partnership issued a preferred unit equivalent to DFT with the same terms. On June 9, 2016 , DFT redeemed 2,650,000 shares of its Series B Preferred Stock at a redemption price of $25 per share, plus accrued and unpaid dividends through the date of redemption. On July 15, 2016 , DFT redeemed the remaining 4,000,000 shares of its Series B Preferred Stock at a redemption price of $25 per share, plus accrued and unpaid dividends through the date of redemption. Accordingly, for the year ended December 31, 2016 , DFT wrote-off the original issuance costs related to the shares of Series B Preferred Stock totaling $6.1 million . For the year ended December 31, 2016 , DFT declared and paid the following cash dividends on its Series B Preferred Stock, of which the OP paid an equivalent distribution on its preferred units: Record Date Payment Date Cash Dividend Ordinary Taxable Dividend (Unaudited) Nontaxable Return of Capital Distributions (Unaudited) 4/1/2016 4/15/2016 $ 0.4765625 $ 0.4765625 $ 0.00 7/1/2016 7/15/2016 0.4765625 0.4765625 0.00 $ 0.9531250 $ 0.9531250 $ 0.00 For the year ended December 31, 2015 , DFT declared and paid the following cash dividends on its Series B Preferred Stock, of which the OP paid an equivalent distribution on its preferred units: Record Date Payment Date Cash Dividend Ordinary Taxable Dividend (Unaudited) Nontaxable Return of Capital Distributions (Unaudited) 4/2/2015 4/15/2015 $ 0.4765625 $ 0.4765625 $ 0.00 7/2/2015 7/15/2015 0.4765625 0.4765625 0.00 10/2/2015 10/15/2015 0.4765625 0.4765625 0.00 12/30/2015 1/15/2016 0.4765625 0.4765625 0.00 $ 1.9062500 $ 1.9062500 $ 0.00 For the year ended December 31, 2014 , DFT declared and paid the following cash dividends on its Series B Preferred Stock, of which the OP paid an equivalent distribution on its preferred units: Record Date Payment Date Cash Dividend Ordinary Taxable Dividend (Unaudited) Nontaxable Return of Capital Distributions (Unaudited) 4/4/2014 4/15/2014 $ 0.4765625 $ 0.4765625 $ 0.00 7/3/2014 7/15/2014 0.4765625 0.4765625 0.00 10/3/2014 10/15/2014 0.4765625 0.4765625 0.00 12/30/2014 1/15/2015 0.4765625 0.4765625 0.00 $ 1.9062500 $ 1.9062500 $ 0.00 Series C Preferred Stock In May 2016, DFT issued 8,050,000 shares of 6.625% Series C Cumulative Redeemable Perpetual Preferred Stock (the "Series C Preferred Stock"), for $201.3 million in an underwritten public offering that resulted in proceeds to the Company, net of underwriting discounts, commissions and other offering costs, of $194.3 million . The liquidation preference on the Series C Preferred Stock is $25 per share and dividends are scheduled quarterly. For each share of Series C Preferred Stock issued by DFT, the Operating Partnership issued a preferred unit equivalent to DFT with the same terms. For the year ended December 31, 2016 , DFT declared the following cash dividends on its Series C Preferred Stock, of which the OP will pay or has paid an equivalent distribution on its preferred units: Record Date Payment Date Cash Dividend Ordinary Taxable Dividend (Unaudited) Nontaxable Return of Capital Distributions (Unaudited) 8/1/2016 8/15/2016 $ 0.4094618 $ 0.4094618 $ 0.00 11/1/2016 11/15/2016 0.4140625 0.4140625 0.00 $ 0.8235243 $ 0.8235243 $ 0.00 Except in instances relating to preservation of our qualification as a REIT or in connection with our special optional redemption right discussed below, our Series C Preferred Stock is not redeemable prior to May 15, 2021 . On and after May 15, 2021, we may, at our option, redeem our Series C Preferred Stock, in whole, at any time, or in part, from time to time, for cash at a redemption price of $25 per share, plus any accrued and unpaid dividends (whether or not declared) to, but not including, the date of redemption. Upon the occurrence of a change of control, we have a special optional redemption right that enables us to redeem the Series C Preferred Stock within 120 days after the first date on which a change of control has occurred resulting in neither DFT nor the surviving entity having a class of common shares listed on the NYSE, NYSE MKT, or NASDAQ. For this special redemption right, the redemption price is $25 per share in cash, plus accrued and unpaid dividends (whether or not declared) to, but not including, the redemption date. Upon the occurrence of a change of control that results in neither DFT nor the surviving entity having a class of common shares listed on the NYSE, NYSE MKT, or NASDAQ, the holder will have the right (subject to our special optional redemption right to redeem the Series C Preferred Stock) to convert some or all of the Series C Preferred Stock into a number of shares of DFT's common stock equal to the lesser of (A) the quotient obtained by dividing (i) the sum of (x) $25 , plus (y) an amount equal to any accrued and unpaid dividends, whether or not declared to, but not including, the date of conversion (unless the date of conversion is after a record date for a Series C Preferred Stock dividend payment and prior to the corresponding Series C Preferred Stock dividend payment date, in which case no additional amount for such accrued and unpaid dividend will be included in this quotient), by (ii) the price of DFT's common stock, and (B) 1.1723 (the Share Cap), subject to certain adjustments and provisions for the receipt of alternative consideration of equivalent value.

11. Stockholders Equity of the

11. Stockholders Equity of the REIT and Partners Capital of the OP	12 Months Ended
	Dec. 31, 2016
Stockholders’ Equity of the REIT and Partners’ Capital of the OP [Abstract]
Stockholders' Equity Of The REIT And Partners' Capital Of The OP [Text Block]	Stockholders’ Equity of DFT and Partners’ Capital of the OP During the years ended December 31, 2016 , 2015 and 2014 : • DFT issued an aggregate of 227,430 , 565,162 and 163,187 shares of common stock, respectively, in connection with our annual grant of restricted stock to employees, the vesting of certain performance unit awards, the hiring of new employees and grants and retainers for our Board of Directors. The OP issued an equivalent number of units to the REIT. • OP unitholders redeemed a total of 1,618,048 , 363,674 and 234,300 OP units, respectively, in exchange for an equal number of shares of DFT’s common stock. For the year ended December 31, 2016 , DFT declared and paid the following cash dividends totaling $1.91 per share on its common stock, of which the OP paid equivalent distributions on OP units: Record Date Payment Date Cash Dividend Ordinary Taxable Dividend (Unaudited) Nontaxable Return of Capital Distributions (Unaudited) 04/01/2016 04/15/2016 $ 0.47 $ 0.26 $ 0.21 07/01/2016 07/15/2016 0.47 0.26 0.21 10/07/2016 10/17/2016 0.47 0.26 0.21 12/30/2016 01/17/2017 0.50 — — $ 1.91 $ 0.78 $ 0.63 All of the $0.50 dividend paid in January 2017 (unaudited), will be included in 2017 common dividends. For the year ended December 31, 2015 , DFT declared and paid the following cash dividends totaling $1.73 per share on its common stock, of which the OP paid equivalent distributions on OP units: Record Date Payment Date Cash Dividend Ordinary Taxable Dividend (Unaudited) Nontaxable Return of Capital Distributions (Unaudited) 04/02/2015 04/15/2015 $ 0.42 $ 0.42 $ — 07/02/2015 07/15/2015 0.42 0.42 — 10/02/2015 10/15/2015 0.42 0.42 — 12/30/2015 01/16/2016 0.47 0.33 — $ 1.73 $ 1.59 $ — Of the $0.47 dividend paid in January 2016, $0.14 (unaudited) was included in 2016 common dividends. For the year ended December 31, 2014 , DFT declared and paid the following cash dividends totaling $1.47 per share on its common stock, of which the OP paid equivalent distributions on OP units: Record Date Payment Date Cash Dividend Ordinary Taxable Dividend (Unaudited) Nontaxable Return of Capital Distributions (Unaudited) 04/04/2014 04/15/2014 $ 0.35 $ 0.35 $ — 07/03/2014 07/15/2014 0.35 0.35 — 10/03/2014 10/15/2014 0.35 0.35 — 12/30/2014 01/15/2015 0.42 0.39 — $ 1.47 $ 1.44 $ — Of the $0.42 dividend paid in January 2015, $0.03 (unaudited) was included in 2015 common dividends. In December 2014, the Board of Directors approved a common stock repurchase program to acquire up to $120.0 million of DFT's common shares in 2015. Under this program, which expired on December 31, 2015 , DFT repurchased 1,002,610 shares of its common stock totaling $31.9 million . All repurchased shares were retired immediately, and the Operating Partnership retired an equivalent number of units. We did not have a repurchase program in 2016. In March 2016, DFT completed a secondary underwritten public offering of 7,613,000 shares of common stock, at a public offering price of $37.75 per share. The total shares sold included 993,000 shares of common stock pursuant to the full exercise of the underwriters’ option to purchase additional shares of common stock. Net proceeds from the offering were approximately $275.5 million , after deducting the underwriting discount and other offering expenses, which DFT contributed to the Operating Partnership in exchange for OP units.

12. Equity Compensation Plan

12. Equity Compensation Plan	12 Months Ended
	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Disclosure of Compensation Related Costs, Share-based Payments [Text Block]	Equity Compensation Plan In May 2011, our Board of Directors adopted the 2011 Equity Incentive Plan (the “2011 Plan”) following approval from our stockholders. The 2011 Plan is administered by the Compensation Committee of our Board of Directors. The 2011 Plan allows us to provide equity-based compensation to our personnel and directors in the form of stock options, stock appreciation rights, dividend equivalent rights, restricted stock, restricted stock units, performance-based awards, unrestricted stock, long term incentive units ("LTIP units") and other awards. The 2011 Plan authorizes a maximum aggregate of 6,300,000 share equivalents be reserved for future issuances. In addition, under the 2011 Plan, shares of common stock that are subject to awards of options or stock appreciation rights will be counted against the 2011 Plan share limit as one share for every one share subject to the award. Any shares of stock that are subject to awards other than options or stock appreciation rights shall be counted against the 2011 Plan share limit as 2.36 shares for every one share subject to the award. As of December 31, 2016 , 3,913,287 share equivalents were issued under the 2011 Plan, and the maximum aggregate amount of share equivalents remaining available for future issuance was 2,386,713 . Restricted Stock Restricted stock awards vest over specified periods of time as long as the employee remains employed with the Company. The following table sets forth the number of unvested shares of restricted stock and the weighted average fair value of these shares at the date of grant: Shares of Restricted Stock Weighted Average Fair Value at Date of Grant Unvested balance at December 31, 2013 303,964 $ 22.89 Granted 149,608 $ 25.63 Vested (125,798 ) $ 23.02 Forfeited (3,785 ) $ 23.98 Unvested balance at December 31, 2014 323,989 $ 24.10 Granted 171,475 $ 32.12 Vested (138,585 ) $ 23.87 Forfeited (7,737 ) $ 28.71 Unvested balance at December 31, 2015 349,142 $ 28.02 Granted 175,410 $ 33.96 Vested (167,419 ) $ 25.66 Forfeited (47,958 ) $ 30.41 Unvested balance at December 31, 2016 309,175 $ 32.30 During the years ended December 31, 2016 , 2015 and 2014 , we issued 175,410 , 171,475 and 149,608 shares of restricted stock, respectively, which had aggregate values of $6.0 million , $5.5 million and $3.8 million , on the respective grant dates. These amounts will be amortized to expense over the respective vesting periods, which are typically three years. Also during the years ended December 31, 2016 , 2015 and 2014 , 167,419 , 138,585 and 125,798 shares of restricted stock vested, respectively, at intrinsic values of $6.2 million , $4.3 million and $3.4 million on their respective vesting dates. As of December 31, 2016 , total unearned compensation on restricted stock was $6.4 million , and the weighted average vesting period was 1.1 years . Stock Options Stock option awards are granted with an exercise price equal to the closing market price of DFT’s common stock at the date of grant and vest over specified periods of time as long as the employee remains employed with the Company. All shares to be issued upon option exercises will be newly issued shares and the options have 10-year contractual terms. During the year ended December 31, 2016 , no options were granted to employees. The last grant of stock options occurred in 2013, and all stock option grants have fully vested. A summary of our stock option activity for the years ended December 31, 2016 , 2015 and 2014 is presented in the tables below. Number of Options Weighted Average Exercise Price Under option, December 31, 2013 2,099,910 $ 17.13 Granted — $ — Exercised (507,056 ) $ 10.95 Forfeited — $ — Under option, December 31, 2014 1,592,854 $ 19.09 Granted — $ — Exercised (362,642 ) $ 21.87 Forfeited — $ — Under option, December 31, 2015 1,230,212 $ 18.28 Granted — $ — Exercised (478,733 ) $ 22.12 Forfeited — $ — Under option, December 31, 2016 751,479 $ 15.83 Shares Subject to Option Total Unearned Compensation Weighted Average Vesting Period Weighted Average Remaining Contractual Term As of December 31, 2014 1,592,854 $ 0.7 million 0.5 years 6.2 years As of December 31, 2015 1,230,212 $ 0.1 million 0.2 years 4.9 years As of December 31, 2016 751,479 $ — 0.0 years 3.6 years The following table sets forth the number of unvested options as of December 31, 2016 , 2015 and 2014 and the weighted average fair value of these options at the grant date. Number of Options Weighted Average Fair Value at Date of Grant Unvested balance at December 31, 2013 684,111 $ 5.73 Granted — $ — Vested (381,787 ) $ 6.28 Forfeited — $ — Unvested balance at December 31, 2014 302,324 $ 5.05 Granted — $ — Vested (263,553 ) $ 5.10 Forfeited — $ — Unvested balance at December 31, 2015 38,771 $ 4.75 Granted — $ — Vested (38,771 ) $ 4.75 Forfeited — $ — Unvested balance at December 31, 2016 — $ — The following tables set forth the number of exercisable options as of December 31, 2016 , 2015 and 2014 and the weighted average fair value and exercise price of these options at the grant date. Number of Options Weighted Average Fair Value at Date of Grant Options Exercisable at December 31, 2013 1,415,799 $ 4.81 Vested 381,787 $ 6.28 Exercised (507,056 ) $ 3.54 Options Exercisable at December 31, 2014 1,290,530 $ 5.74 Vested 263,553 $ 5.10 Exercised (362,642 ) $ 6.34 Options Exercisable at December 31, 2015 1,191,441 $ 5.41 Vested 38,771 $ 4.75 Exercised (478,733 ) $ 6.46 Options Exercisable at December 31, 2016 751,479 $ 4.71 Exercisable Options Intrinsic Value Weighted Average Exercise Price Weighted Average Remaining Contractual Term As of December 31, 2014 1,290,530 $ 19.3 million $ 18.27 5.8 years As of December 31, 2015 1,191,441 $ 16.3 million $ 18.14 4.9 years As of December 31, 2016 751,479 $ 21.1 million $ 15.83 3.6 years The intrinsic value of stock options exercised during the years ended December 31, 2016 , 2015 and 2014 was $5.2 million , $3.7 million and $7.7 million , respectively. Performance Units Performance unit awards are awarded to certain executive employees and have a three calendar-year performance period with no dividend rights. Performance units are settled in common shares following the performance period as long as the employee remains employed with us on the vesting date following the last day of the applicable performance period. Performance units are valued using a Monte Carlo simulation and are amortized over approximately a three year vesting period from the grant date to the vesting date. The number of common shares settled could range from 0% to 300% . For performance unit award grants prior to 2014, the vesting amount is dependent on DFT’s total stockholder return compared to the MSCI US REIT index over the three calendar-year performance period. For performance unit grants awarded in 2014 and thereafter, one-half of the recipient's performance unit award is dependent on DFT’s total stockholder return compared to the MSCI US REIT index over the three calendar-year performance period. The other half of the performance unit award is dependent on DFT’s total stockholder return compared to an index of five comparable publicly traded data center companies over the three calendar-year performance period. The following table summarizes the assumptions used to value, and the resulting fair and maximum values of, the performance units granted during the years ended December 31, 2016 , 2015 and 2014 . 2016 2015 2014 Number of performance units granted 112,951 48,674 110,441 Expected volatility 24% 24% 30% Expected annual dividend 6% 5% 5% Risk-free rate 1.32% 1.06% 0.74% Performance unit fair value at date of grant $38.08 $38.34 $33.50 Total grant fair value at date of grant $4.3 million $1.9 million $3.7 million Maximum value of grant on vesting date based on closing price of DFT's stock at the date of grant $10.7 million $4.7 million $8.5 million The following table sets forth the number of performance units outstanding and the fair value per unit at the date of grant as of December 31, 2016 . Grant Date Grant Date Fair Value per Unit Units Granted Units Vested Units Accelerated (1) Units Forfeited Units Outstanding Payout Total Shares Issued 2/23/2012 (2) $28.26 61,033 (49,936 ) — (11,097 ) — —% — 2/21/2013 (3) $25.59 60,468 (10,995 ) (38,479 ) (10,994 ) — 300% 148,422 2/21/2014 (4) $33.50 110,441 — (70,538 ) (1,785 ) 38,118 (4) 207,365 3/16/2015 $38.34 48,674 — (651 ) (2,440 ) 45,583 100% 651 1/5/2016 $38.08 112,951 — — — 112,951 393,567 (60,931 ) (109,668 ) (26,316 ) 196,652 356,438 (1) Represents accelerated vesting of performance units due to departure of certain executives. In connection with the departure of our former CEO in February 2015, 320,676 common shares were issued pursuant to the accelerated vesting of certain of his unvested performance units. $1.9 million was expensed during the first quarter of 2015 related to the accelerated vesting of these performance units. (2) For the performance units granted in 2012, based on DFT’s total stockholder return compared to the MSCI US REIT index return for the period from January 1, 2012 to January 1, 2015, no common shares were issued upon vesting on March 1, 2015. (3) For the performance units granted in 2013, 115,437 common shares were issued due to the accelerated vesting of certain unvested performance units, which represented a 300% payout. Based on DFT’s total stockholder return compared to the MSCI US REIT index return for the period from January 1, 2013 to January 1, 2016, 32,985 common shares were issued upon the vesting of these performance units on March 1, 2016, which represented a 300% payout. (4) For the performance units granted in 2014, 205,240 common shares were issued, which represented a 300% payout, and 2,125 common shares were issued, which represented a 100% payout, due to the accelerated vesting of certain unvested performance units. Based on DFT’s total stockholder return compared to the MSCI US REIT index return for half of the grant and an index of five comparable publicly traded data center companies for the other half of the grant for the period from January 1, 2014 to January 1, 2017, 57,177 common shares will be issued upon their vesting on March 1, 2017, which represents an aggregate payout of 150% . During the year ended December 31, 2016 , no performance units were forfeited. During the year ended December 31, 2015 , 4,225 performance units were forfeited with a weighted average fair value of $36.30 per unit. During the year ended December 31, 2014 , no performance units were forfeited. As of December 31, 2016 , total unearned compensation on outstanding performance units was $3.7 million .

13. Earnings Per Share of the R

13. Earnings Per Share of the REIT	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Earnings Per Share [Text Block]	Earnings (Loss) Per Share of DFT The following table sets forth the reconciliation of basic and diluted average shares outstanding used in the computation of earnings per share of common stock (in thousands except for share and per share amounts): Twelve months ended December 31, 2016 2015 2014 Basic and Diluted Shares Outstanding Weighted average common shares – basic 73,003,164 65,184,013 65,486,108 Effect of dilutive securities 835,872 — 600,271 Weighted average common shares – diluted 73,839,036 65,184,013 66,086,379 Calculation of Earnings per Share – Basic Net income (loss) attributable to common shares $ 123,965 $ (25,338 ) $ 78,662 Net income allocated to unvested restricted shares (628 ) (599 ) (484 ) Net income (loss) attributable to common shares, adjusted 123,337 (25,937 ) 78,178 Weighted average common shares – basic 73,003,164 65,184,013 65,486,108 Earnings (loss) per common share – basic $ 1.69 $ (0.40 ) $ 1.19 Calculation of Earnings per Share – Diluted Net income (loss) attributable to common shares, adjusted $ 123,337 $ (25,937 ) $ 78,178 Weighted average common shares – diluted 73,839,036 65,184,013 66,086,379 Earnings (loss) per common share – diluted $ 1.67 $ (0.40 ) $ 1.18 The following table sets forth the amount of stock options and performance units that have been excluded from the calculation of diluted earnings per share (in millions): Twelve months ended December 31, 2016 2015 2014 Stock Options — 0.6 — Performance Units 0.1 0.1 0.1 All of the stock options were antidilutive for the twelve months ended December 31, 2015 because of the net loss incurred during the year. The performance units presented above for the twelve months ended December 31, 2016 , 2015 and 2014 were antidilutive because the vesting conditions for these awards were not met in each of these years.

14. Earnings Per Unit of the Op

14. Earnings Per Unit of the Operating Partnership	12 Months Ended
	Dec. 31, 2016
Earnings Per Unit [Abstract]
Earnings per unit of the Operating Partnership [Text Block]	Earnings (Loss) Per Unit of the Operating Partnership The following table sets forth the reconciliation of basic and diluted average units outstanding used in the computation of earnings per unit: Twelve months ended December 31, 2016 2015 2014 Basic and Diluted Units Outstanding Weighted average common units – basic (includes redeemable partnership units and units of general and limited partners) 87,284,564 80,599,199 81,053,127 Effect of dilutive securities 835,872 — 600,271 Weighted average common units – diluted 88,120,436 80,599,199 81,653,398 Calculation of Earnings per Unit – Basic Net income (loss) attributable to common units 148,213 (31,331 ) 97,366 Net income allocated to unvested restricted units (628 ) (599 ) (484 ) Net income (loss) attributable to common units, adjusted 147,585 (31,930 ) 96,882 Weighted average common units – basic 87,284,564 80,599,199 81,053,127 Earnings (loss) per common unit – basic $ 1.69 $ (0.40 ) $ 1.19 Calculation of Earnings per Unit – Diluted Net income (loss) attributable to common units, adjusted 147,585 (31,930 ) 96,882 Weighted average common units – diluted 88,120,436 80,599,199 81,653,398 Earnings per common unit – diluted $ 1.67 $ (0.40 ) $ 1.18 The following table sets forth the amount of stock options and performance units that have been excluded from the calculation of diluted earnings per unit (in millions): Twelve months ended December 31, 2016 2015 2014 Stock Options — 0.6 — Performance Units 0.1 0.1 0.1 All of the stock options were antidilutive for the twelve months ended December 31, 2015 because of the net loss incurred during the year. The performance units presented above for the twelve months ended December 31, 2016 , 2015 and 2014 were antidilutive because the vesting conditions for these awards were not met in each of these years.

15. Employee Benefit Plan (Note

15. Employee Benefit Plan (Notes)	12 Months Ended
	Dec. 31, 2016
Compensation and Employee Benefit Plans [Text Block]	Employee Benefit Plan We have a tax qualified retirement plan (“401(k) Plan”) that provides employees with an opportunity to save for retirement on a tax advantaged basis. Employees participate in the 401(k) Plan on their first day of employment and are able to defer compensation up to the limits established by the Internal Revenue Service. We match 50% of the employees' contributions up to a maximum match contribution of 4% of the employees' eligible compensation. Our contributions vest immediately. For the years ended December 31, 2016 , 2015 and 2014 we contributed $0.6 million , $0.5 million and $0.4 million , respectively, to the 401(k) Plan.

16. Fair Value

16. Fair Value	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value Disclosures [Text Block]	Fair Value Assets and Liabilities Measured at Fair Value We follow the authoritative guidance issued by the FASB relating to fair value measurements that defines fair value, establishes a framework for measuring fair value, and expands disclosures about fair value measurements. The guidance applies to reported balances that are required or permitted to be measured at fair value under existing accounting pronouncements; accordingly, the guidance does not require any new fair value measurements of reported balances. The guidance excludes the accounting for leases, as well as other authoritative guidance that address fair value measurements on lease classification and measurement. The authoritative guidance issued by the FASB emphasizes that fair value is a market-based measurement, not an entity-specific measurement. Therefore, a fair value measurement should be determined based on the assumptions that market participants would use in pricing the asset or liability. Level 1 inputs utilize quoted prices (unadjusted) in active markets for identical assets or liabilities that we have the ability to access. Level 2 inputs are inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. Level 2 inputs may include quoted prices for similar assets and liabilities in active markets, as well as inputs that are observable for the asset or liability (other than quoted prices), such as interest rates, foreign exchange rates, and yield curves that are observable at commonly quoted intervals. Level 3 inputs are unobservable inputs for the asset or liability, which are typically based on an entity's own assumptions, as there is little, if any, related market activity. In instances where the determination of the fair value measurement is based on inputs from different levels of the fair value hierarchy, the level in the fair value hierarchy within which the entire fair value measurement falls is based on the lowest level input that is significant to the fair value measurement in its entirety. Our assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment, and considers factors specific to the asset or liability. The authoritative guidance issued by the FASB requires disclosure of the fair value of financial instruments. Fair value estimates are subjective in nature and are dependent on a number of important assumptions, including estimates of future cash flows, risks, discount rates, and relevant comparable market information associated with each financial instrument. The use of different market assumptions and estimation methodologies may have a material effect on the reported estimated fair value amounts. Accordingly, the amounts are not necessarily indicative of the amounts we would realize in a current market exchange. The following methods and assumptions were used in estimating the fair value amounts and disclosures for financial instruments as of December 31, 2016 and 2015 : • Cash and cash equivalents: The carrying amount of cash and cash equivalents reported in the accompanying consolidated balance sheets approximates fair value because of the short maturity of these instruments (i.e., less than 90 days). • Rents and other receivables, accounts payable and accrued liabilities, and prepaid rents: The carrying amount of these assets and liabilities reported in the accompanying consolidated balance sheets approximates fair value because of the short-term nature of these amounts. • Debt: As of December 31, 2016 , the combined balance of the Unsecured Notes due 2021, Unsecured Notes due 2023, Unsecured Term Loan, Unsecured Credit Facility and ACC3 Term Loan, excluding the effect of deferred financing costs, was $1,260.5 million with a fair value of $1,291.0 million . The Unsecured Notes due 2021 and the Unsecured Notes due 2023 were valued based on Level 2 data which consisted of a quoted price from Bloomberg. The Unsecured Term Loan, the US dollar-denominated borrowings under the Unsecured Credit facility and ACC3 Term Loan were valued based on Level 3 data which consisted of a one-month LIBOR swap rate coterminous with the maturity of each loan plus a spread consistent with current market conditions. The Canadian dollar-denominated borrowings under the Unsecured Credit facility were valued based on Level 3 data which consisted of a one-month Canadian Dollar Offered Rate swap rate coterminous with the maturity of the Unsecured Credit Facility plus a spread consistent with current market conditions. As of December 31, 2015 , the combined balance of the Unsecured Notes due 2021, Unsecured Notes due 2023, Unsecured Term Loan and ACC3 Term Loan, excluding the effect of deferred financing costs, was $1,213.1 million with a fair value of $1,237.2 million . The Unsecured Notes due 2021 and the Unsecured Notes due 2023 were valued based on Level 2 data which consisted of a quoted price from Bloomberg. The ACC3 Loan and the Unsecured Term Loan were valued based on Level 3 data which consisted of a one-month LIBOR swap rate coterminous with the maturity of each loan plus a spread consistent with current market conditions.

17. Quarterly Financial Informa

17. Quarterly Financial Information (Notes)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information [Text Block]	Quarterly Financial Information (unaudited) The table below reflects the selected quarterly information for the years ended December 31, 2016 and 2015 (in thousands except share data): Three months ended December 31, 2016 September 30, 2016 June 30, 2016 March 31, 2016 Total revenue $ 141,688 $ 134,326 $ 128,538 $ 124,149 Net income (1) 43,227 40,966 60,557 36,697 Net income attributable to common shares (1) 33,734 28,524 37,299 24,408 Net income attributable to common shares per common share-basic (1) 0.45 0.38 0.50 0.36 Net income attributable to common shares per common share-diluted (1) (2) 0.44 0.37 0.49 0.36 Three months ended December 31, 2015 September 30, 2015 June 30, 2015 March 31, 2015 Total revenue $ 115,923 $ 115,337 $ 113,826 $ 107,314 Net (loss) income (3) (91,953 ) 30,393 31,141 26,333 Net (loss) income attributable to common shares (3) (79,871 ) 19,062 19,668 15,803 Net (loss) income attributable to common shares per common share-basic (3) (1.23 ) 0.29 0.30 0.24 Net (loss) income attributable to common shares per common share-diluted (3) (1.23 ) 0.29 0.30 0.24 (1) Net income for the quarter ended June 30, 2016 includes a gain on sale of real estate of $22.8 million . (2) Amounts do not equal full year results due to rounding. (3) Net loss for the quarter ended December 31, 2015 includes an impairment on investment in real estate of $122.5 million .

18. Supplemental Consolidating

18. Supplemental Consolidating Financial Data for Subsidiary Guarantors of the Unsecured Notes	12 Months Ended
	Dec. 31, 2016
Supplemental Consolidating Financial Data for Subsidiary Guarantors of the Unsecured Notes [Abstract]
Additional Financial Information Disclosure [Text Block]	Supplemental Consolidating Financial Data for Subsidiary Guarantors of the Unsecured Notes The Unsecured Notes due 2021 and the Unsecured Notes due 2023 are unconditionally guaranteed, jointly and severally, on a senior unsecured basis by DFT and certain of the Operating Partnership’s subsidiaries, including the subsidiaries that own the ACC2, ACC4, ACC5, ACC6, VA3, VA4, CH1 and SC1 data centers (collectively, the “Subsidiary Guarantors”), but excluding the subsidiaries that own the ACC3, ACC7, ACC9, ACC10, CH2, CH3 and TOR1 data centers, the ACC8, ACC11, OR1 and OR2 parcels of land, our taxable REIT subsidiary, DF Technical Services LLC and our property management subsidiary, DF Property Management LLC. The following consolidating financial information sets forth the financial position as of December 31, 2016 and December 31, 2015 and the results of operations and cash flows for the years ended December 31, 2016 , 2015 and 2014 of the Operating Partnership, Subsidiary Guarantors and the Subsidiary Non-Guarantors. DUPONT FABROS TECHNOLOGY, L.P. SUPPLEMENTAL CONSOLIDATING BALANCE SHEETS (in thousands except share data) December 31, 2016 Operating Partnership Subsidiary Guarantors Subsidiary Non-Guarantors Eliminations Consolidated Total ASSETS Income producing property: Land $ — $ 80,673 $ 25,217 $ — $ 105,890 Buildings and improvements — 2,332,771 685,590 — 3,018,361 — 2,413,444 710,807 — 3,124,251 Less: accumulated depreciation — (605,488 ) (56,695 ) — (662,183 ) Net income producing property — 1,807,956 654,112 — 2,462,068 Construction in progress and land held for development — 88,836 242,147 — 330,983 Net real estate — 1,896,792 896,259 — 2,793,051 Cash and cash equivalents 31,781 — 2,628 — 34,409 Rents and other receivables 1,390 4,743 5,400 — 11,533 Deferred rent — 109,142 13,916 — 123,058 Lease contracts above market value, net — 5,138 — — 5,138 Deferred costs, net 6,066 11,632 8,078 — 25,776 Investment in affiliates 2,713,096 — — (2,713,096 ) — Prepaid expenses and other assets 3,463 27,341 10,480 — 41,284 Total assets $ 2,755,796 $ 2,054,788 $ 936,761 $ (2,713,096 ) $ 3,034,249 LIABILITIES AND PARTNERS’ CAPITAL Liabilities: Line of credit $ 50,926 $ — $ — $ — $ 50,926 Mortgage notes payable, net of deferred financing costs — — 110,733 — 110,733 Unsecured term loan, net of deferred financing costs 249,036 — — — 249,036 Unsecured notes payable, net of discount and deferred financing costs 837,323 — — — 837,323 Accounts payable and accrued liabilities 6,477 22,319 8,113 — 36,909 Construction costs payable — 10,159 46,269 — 56,428 Accrued interest payable 11,578 — 14 — 11,592 Distribution payable 46,352 — — — 46,352 Lease contracts below market value, net — 2,830 — — 2,830 Prepaid rents and other liabilities 216 58,599 19,417 — 78,232 Total liabilities 1,201,908 93,907 184,546 — 1,480,361 Redeemable partnership units 591,101 — — — 591,101 Commitments and contingencies — — — — — Limited Partners’ Capital: Series C cumulative redeemable perpetual preferred units, 8,050,000 issued and outstanding at December 31, 2016 201,250 — — — 201,250 Common units, 75,252,390 issued and outstanding at December 31, 2016 754,892 1,960,881 752,215 (2,713,096 ) 754,892 General partner’s capital, 662,373 common units issued and outstanding at December 31, 2016 6,645 — — — 6,645 Total partners’ capital 962,787 1,960,881 752,215 (2,713,096 ) 962,787 Total liabilities & partners’ capital $ 2,755,796 $ 2,054,788 $ 936,761 $ (2,713,096 ) $ 3,034,249 DUPONT FABROS TECHNOLOGY, L.P. SUPPLEMENTAL CONSOLIDATING BALANCE SHEETS (in thousands except share data) December 31, 2015 Operating Partnership Subsidiary Guarantors Subsidiary Non-Guarantors Eliminations Consolidated Total ASSETS Income producing property: Land $ — $ 84,258 $ 9,945 $ — $ 94,203 Buildings and improvements — 2,399,016 337,920 — 2,736,936 — 2,483,274 347,865 — 2,831,139 Less: accumulated depreciation — (522,096 ) (38,741 ) — (560,837 ) Net income producing property — 1,961,178 309,124 — 2,270,302 Construction in progress and land held for development — 25,545 275,394 — 300,939 Net real estate — 1,986,723 584,518 — 2,571,241 Cash and cash equivalents 21,697 — 5,318 — 27,015 Rents and other receivables 1,391 7,563 634 — 9,588 Deferred rent — 122,830 6,111 — 128,941 Lease contracts above market value, net — 6,029 — — 6,029 Deferred costs, net 3,236 14,250 6,288 — 23,774 Investment in affiliates 2,546,465 — — (2,546,465 ) — Prepaid expenses and other assets 3,025 39,642 2,022 — 44,689 Total assets $ 2,575,814 $ 2,177,037 $ 604,891 $ (2,546,465 ) $ 2,811,277 LIABILITIES AND PARTNERS’ CAPITAL Liabilities: Line of credit $ — $ — $ — $ — $ — Mortgage notes payable, net of deferred financing costs — — 114,075 — 114,075 Unsecured term loan, net of deferred financing costs 249,172 — — — 249,172 Unsecured notes payable, net of discount and deferred financing costs 834,963 — — — 834,963 Accounts payable and accrued liabilities 4,516 23,615 4,170 — 32,301 Construction costs payable 43 293 21,707 — 22,043 Accrued interest payable 11,815 — 6 — 11,821 Distribution payable 43,906 — — — 43,906 Lease contracts below market value, net — 4,132 — — 4,132 Prepaid rents and other liabilities 12 62,630 4,835 — 67,477 Total liabilities 1,144,427 90,670 144,793 — 1,379,890 Redeemable partnership units 479,189 — — — 479,189 Commitments and contingencies — — — — — Limited Partners’ Capital: Series A cumulative redeemable perpetual preferred units, 7,400,000 issued and outstanding at December 31, 2015 185,000 — — — 185,000 Series B cumulative redeemable perpetual preferred units, 6,650,000 issued and outstanding at December 31, 2015 166,250 — — — 166,250 Common units, 65,443,277 issued and outstanding at December 31, 2015 594,927 2,086,367 460,098 (2,546,465 ) 594,927 General partner’s capital, 662,373 common units issued and outstanding at December 31, 2015 6,021 — — — 6,021 Total partners’ capital 952,198 2,086,367 460,098 (2,546,465 ) 952,198 Total liabilities & partners’ capital $ 2,575,814 $ 2,177,037 $ 604,891 $ (2,546,465 ) $ 2,811,277 Year ended December 31, 2016 Operating Partnership Subsidiary Guarantors Subsidiary Non-Guarantors Eliminations Consolidated Total Revenues: Base rent $ 18,164 $ 270,357 $ 74,727 $ (18,226 ) $ 345,022 Recoveries from tenants — 142,863 26,805 — 169,668 Other revenues — 1,668 12,388 (45 ) 14,011 Total revenues 18,164 414,888 113,920 (18,271 ) 528,701 Expenses: Property operating costs — 144,935 27,338 (18,209 ) 154,064 Real estate taxes and insurance — 16,916 3,264 — 20,180 Depreciation and amortization 100 88,321 19,360 — 107,781 General and administrative 22,009 52 982 — 23,043 Other expenses 1,564 45 10,234 (62 ) 11,781 Total expenses 23,673 250,269 61,178 (18,271 ) 316,849 Operating (loss) income (5,509 ) 164,619 52,742 — 211,852 Interest: Expense incurred (56,318 ) 1,270 6,754 — (48,294 ) Amortization of deferred financing costs (3,907 ) 79 116 — (3,712 ) Gain on sale of real estate 21,643 — 1,190 — 22,833 Loss on early extinguishment of debt (1,232 ) — — — (1,232 ) Equity in earnings 226,770 — — (226,770 ) — Net income (loss) 181,447 165,968 60,802 (226,770 ) 181,447 Preferred unit distributions (20,739 ) — — — (20,739 ) Issuance costs associated with redeemed preferred units (12,495 ) — — — (12,495 ) Net income (loss) attributable to common units $ 148,213 $ 165,968 $ 60,802 $ (226,770 ) $ 148,213 Year ended December 31, 2015 Operating Partnership Subsidiary Guarantors Subsidiary Non-Guarantors Eliminations Consolidated Total Revenues: Base rent $ 18,061 $ 268,433 $ 30,302 $ (18,211 ) $ 298,585 Recoveries from tenants — 127,877 11,660 — 139,537 Other revenues — 1,787 12,621 (130 ) 14,278 Total revenues 18,061 398,097 54,583 (18,341 ) 452,400 Expenses: Property operating costs — 131,644 16,598 (18,191 ) 130,051 Real estate taxes and insurance — 19,942 1,393 — 21,335 Depreciation and amortization 43 94,371 9,630 — 104,044 General and administrative 17,574 57 433 — 18,064 Impairment on investment in real estate — 119,267 3,205 — 122,472 Other expenses 6,151 133 10,725 (150 ) 16,859 Total expenses 23,768 365,414 41,984 (18,341 ) 412,825 Operating (loss) income (5,707 ) 32,683 12,599 — 39,575 Interest: Expense incurred (50,021 ) 1,327 8,184 — (40,510 ) Amortization of deferred financing costs (3,454 ) 107 196 — (3,151 ) Equity in earnings 55,096 — — (55,096 ) — Net (loss) income (4,086 ) 34,117 20,979 (55,096 ) (4,086 ) Preferred unit distributions (27,245 ) — — — (27,245 ) Net (loss) income attributable to common units $ (31,331 ) $ 34,117 $ 20,979 $ (55,096 ) $ (31,331 ) Year ended December 31, 2014 Operating Partnership Subsidiary Guarantors Subsidiary Non-Guarantors Eliminations Consolidated Total Revenues: Base rent $ 17,499 $ 267,454 $ 18,413 $ (17,650 ) $ 285,716 Recoveries from tenants — 115,185 9,668 — 124,853 Other revenues — 1,657 5,489 (123 ) 7,023 Total revenues 17,499 384,296 33,570 (17,773 ) 417,592 Expenses: Property operating costs — 123,140 11,822 (17,623 ) 117,339 Real estate taxes and insurance — 13,323 872 — 14,195 Depreciation and amortization 63 90,770 5,947 — 96,780 General and administrative 16,159 82 940 — 17,181 Other expenses 3,508 1,526 4,338 (150 ) 9,222 Total expenses 19,730 228,841 23,919 (17,773 ) 254,717 Operating (loss) income (2,231 ) 155,455 9,651 — 162,875 Interest: Expense incurred (41,107 ) 4,323 3,201 — (33,583 ) Amortization of deferred financing costs (3,173 ) 273 (80 ) — (2,980 ) Loss on early extinguishment of debt (1,701 ) — — — (1,701 ) Equity in earnings 172,823 — — (172,823 ) — Net income 124,611 160,051 12,772 (172,823 ) 124,611 Preferred unit distributions (27,245 ) — — — (27,245 ) Net income attributable to common units $ 97,366 $ 160,051 $ 12,772 $ (172,823 ) $ 97,366 DUPONT FABROS TECHNOLOGY, L.P. SUPPLEMENTAL CONSOLIDATING STATEMENTS OF CASH FLOWS (in thousands) Year ended December 31, 2016 Operating Partnership Subsidiary Guarantors Subsidiary Non-Guarantors Eliminations Consolidated Total Cash flow from operating activities Net cash (used in) provided by operating activities $ (60,010 ) $ 265,244 $ 84,728 $ — $ 289,962 Return on investment in subsidiaries 349,972 — — (349,972 ) — Net cash provided by operating activities 289,962 265,244 84,728 (349,972 ) 289,962 Cash flow from investing activities Proceeds from the sale of real estate — 120,086 3,459 — 123,545 Investments in real estate – development — (62,343 ) (232,421 ) — (294,764 ) Acquisition of real estate — — (53,105 ) — (53,105 ) Acquisition of real estate – related party — — (20,168 ) — (20,168 ) Investments in subsidiaries (384,605 ) — — 384,605 — Return of investment in subsidiaries 123,545 — — (123,545 ) — Interest capitalized for real estate under development (2 ) (1,269 ) (9,109 ) — (10,380 ) Improvements to real estate — (4,739 ) (104 ) — (4,843 ) Additions to non real estate property (1,008 ) (220 ) (42 ) — (1,270 ) Net cash (used in) provided by investing activities (262,070 ) 51,515 (311,490 ) 261,060 (260,985 ) Cash flow from financing activities Line of credit: Proceeds 135,899 — — — 135,899 Repayments (85,000 ) — — — (85,000 ) Mortgage notes payable: Repayments — — (3,750 ) — (3,750 ) Payments of financing costs (5,841 ) — (25 ) — (5,866 ) Issuance of common units, net of offering costs 275,470 — — — 275,470 Issuance of preferred units, net of offering costs 194,252 — — — 194,252 Redemption of preferred units (351,250 ) — — — (351,250 ) Equity compensation proceeds 7,623 — — — 7,623 Parent financing — 68,571 316,034 (384,605 ) — Distribution to parent — (385,330 ) (88,187 ) 473,517 — Distributions (188,961 ) — — — (188,961 ) Net cash (used in) provided by financing activities (17,808 ) (316,759 ) 224,072 88,912 (21,583 ) Net increase (decrease) in cash and cash equivalents 10,084 — (2,690 ) — 7,394 Cash and cash equivalents, beginning of period 21,697 — 5,318 — 27,015 Cash and cash equivalents, ending of period $ 31,781 $ — $ 2,628 $ — $ 34,409 DUPONT FABROS TECHNOLOGY, L.P. SUPPLEMENTAL CONSOLIDATING STATEMENTS OF CASH FLOWS (in thousands) Year ended December 31, 2015 Operating Partnership Subsidiary Guarantors Subsidiary Non-Guarantors Eliminations Consolidated Total Cash flow from operating activities Net cash (used in) provided by operating activities $ (55,999 ) $ 278,557 $ 32,466 $ — $ 255,024 Cash flow from investing activities Investments in real estate – development (415 ) (8,996 ) (207,928 ) — (217,339 ) Acquisition of real estate — — (8,600 ) — (8,600 ) Investments in subsidiaries 68,074 (264,211 ) 196,137 — — Interest capitalized for real estate under development (27 ) (1,327 ) (10,210 ) — (11,564 ) Improvements to real estate — (3,401 ) (58 ) — (3,459 ) Additions to non real estate property (93 ) (622 ) (38 ) — (753 ) Net cash provided by (used in) investing activities 67,539 (278,557 ) (30,697 ) — (241,715 ) Cash flow from financing activities Line of credit: Proceeds 120,000 — — — 120,000 Repayments (180,000 ) — — — (180,000 ) Unsecured notes payable: Proceeds 248,012 — — — 248,012 Payments of financing costs (4,715 ) — (25 ) — (4,740 ) Equity compensation proceeds 249 — — — 249 OP unit repurchases (31,912 ) — — — (31,912 ) Distributions (163,283 ) — — — (163,283 ) Net cash (used in) financing activities (11,649 ) — (25 ) — (11,674 ) Net (decrease) increase in cash and cash equivalents (109 ) — 1,744 — 1,635 Cash and cash equivalents, beginning of period 21,806 — 3,574 — 25,380 Cash and cash equivalents, ending of period $ 21,697 $ — $ 5,318 $ — $ 27,015 Year ended December 31, 2014 Operating Partnership Subsidiary Guarantors Subsidiary Non-Guarantors Eliminations Consolidated Total Cash flow from operating activities Net cash (used in) provided by operating activities $ (40,234 ) $ 264,409 $ 20,339 $ — $ 244,514 Cash flow from investing activities Investments in real estate – development (404 ) (111,791 ) (153,179 ) — (265,374 ) Investments in subsidiaries 5,654 (146,188 ) 140,534 — — Interest capitalized for real estate under development (10 ) (4,323 ) (5,311 ) — (9,644 ) Improvements to real estate — (1,850 ) (66 ) — (1,916 ) Additions to non real estate property (20 ) (257 ) (39 ) — (316 ) Net cash provided by (used) in investing activities 5,220 (264,409 ) (18,061 ) — (277,250 ) Cash flow from financing activities Line of credit: Proceeds 60,000 — — — 60,000 Unsecured term loan: Proceeds 96,000 — — — 96,000 Payments of financing costs (3,514 ) — (315 ) — (3,829 ) Equity compensation proceeds 4,363 — — — 4,363 Distributions (132,932 ) — — — (132,932 ) Net cash provided by (used in) financing activities 23,917 — (315 ) — 23,602 Net (decrease) increase in cash and cash equivalents (11,097 ) — 1,963 — (9,134 ) Cash and cash equivalents, beginning of period 32,903 — 1,611 — 34,514 Cash and cash equivalents, ending of period $ 21,806 $ — $ 3,574 $ — $ 25,380

19. Subsequent Events (Notes)

19. Subsequent Events (Notes)	12 Months Ended
	Dec. 31, 2016
Subsequent Events [Abstract]
Subsequent Events [Text Block]	Subsequent Events In February 2017, we entered into a purchase and sale agreement with an unrelated party to purchase 56.5 acres of undeveloped land in Mesa, Arizona for a purchase price of $12.2 million . During the period from January 1, 2017 through February 23, 2017, OP unitholders redeemed a total of 1,409,147 OP units in exchange for an equal number of shares of DFT's common stock.

Schedule II - Consolidated Allo

Schedule II - Consolidated Allowance for Doubtful Accounts (Notes)	12 Months Ended
	Dec. 31, 2016
SEC Schedule II, Consolidated Allowance for Doubtful Accounts [Abstract]
Schedule of Valuation and Qualifying Accounts Disclosure [Text Block]	Balance at Beginning of Period Charged to Operations (1) Other Accounts (2) Deductions Balance at End of Period Allowance for doubtful accounts: Twelve months ended December 31, 2016 $ 5,241 $ (108 ) $ 18,486 $ — $ 23,619 Twelve months ended December 31, 2015 8,520 372 — (3,651 ) 5,241 Twelve months ended December 31, 2014 3,700 4,829 — (9 ) 8,520 (1) Amounts charged to operations are net of recoveries. (2) Relates to an allowance on a $25.0 million note receivable which resulted from the settlement of our claim in a former customer's bankruptcy proceedings in the fourth quarter of 2016 (see Footnote 2 to consolidated financial statements).

Schedule III - Consolidated Rea

Schedule III - Consolidated Real Estate and Accumulated Depreciation (Notes)	12 Months Ended
	Dec. 31, 2016
Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule III, Real Estate and Accumulated Depreciation Disclosure [Text Block]	Encum-brances Initial Cost at Costs Capitalized Gross Carry Amount at Accumulated Year Year Life on which depreciation in latest income statements is computed Land Building and improvements / Construction in progress Buildings & Land Building and improvements / Construction in progress Total Operating Properties ACC2 (1) $ — $ 2,500 $ 157,100 $ (620 ) $ 2,500 $ 156,480 $ 158,980 $ (57,184 ) 2005 2001 28.5 ACC3 (2) 111,250 1,071 92,631 3,449 $ 1,071 96,080 97,151 (36,136 ) 2006 2001 29.8 ACC4 (1) — 6,600 535,526 3,343 $ 6,600 538,869 545,469 (176,477 ) 2007 2006 30.8 ACC5 (1) — 6,443 292,369 6,647 $ 6,443 299,016 305,459 (71,347 ) 2009-2010 2007 29.7 ACC6 (1) — 5,518 215,235 1,594 $ 5,518 216,829 222,347 (35,197 ) 2011-2013 2007 30.7 ACC7 — 9,753 328,520 4,450 $ 9,753 332,970 342,723 (13,320 ) 2014-2016 2011 32.5 CH1 (1) — 23,611 357,194 1,977 $ 23,611 359,171 382,782 (82,947 ) 2008-2012 2007 30.5 CH2 — 14,392 255,593 946 $ 14,392 256,539 270,931 (7,239 ) 2015-2016 2013 30.7 SC1 Phases I-II (1) — 20,202 429,572 3,527 $ 20,202 433,099 453,301 (53,697 ) 2011-2015 2007 31.7 VA3 (1) — 9,000 172,881 6,813 $ 9,000 179,694 188,694 (72,725 ) 2003 2003 30.5 VA4 (1) — 6,800 140,575 9,039 $ 6,800 149,614 156,414 (55,914 ) 2005 2005 31.1 Subtotal 111,250 105,890 2,977,196 41,165 105,890 3,018,361 3,124,251 (662,183 ) Development Properties ACC8 — 3,786 466 — 3,786 466 4,252 — 2007 ACC9 — 8,469 138,561 — 8,469 138,561 147,030 — 2016 ACC10 — 7,343 1,872 — 7,343 1,872 9,215 — 2016 ACC11 — 4,773 6 — 4,773 6 4,779 — 2016 CH3 — 8,578 8,740 — 8,578 8,740 17,318 — 2015 OR1 — 5,775 1,328 — 5,775 1,328 7,103 — 2016 OR2 — 5,775 301 — 5,775 301 6,076 — 2016 SC1 Phase III (1) — 5,232 83,604 — 5,232 83,604 88,836 — 2007 TOR1 — 42,128 4,246 — 42,128 4,246 46,374 — 2016 Subtotal — 91,859 239,124 — 91,859 239,124 330,983 — Grand Total (3) $ 111,250 $ 197,749 $ 3,216,320 $ 41,165 $ 197,749 $ 3,257,485 $ 3,455,234 $ (662,183 ) (1) The subsidiaries that own these data centers and development properties are guarantors of the Unsecured Notes due 2021 and 2023, the Unsecured Credit Facility and the Unsecured Term Loan. (2) The subsidiary that owns this data center is encumbered by our ACC3 Term Loan. (3) The aggregate gross cost of our properties for federal income tax purposes was $2.78 billion (unaudited) as of December 31, 2016 . 2016 2015 2014 Real estate assets Balance, beginning of period $ 3,132,078 $ 3,066,297 $ 2,799,010 Additions - property acquisitions 73,273 8,600 — Additions - improvements 344,960 221,588 267,357 Deductions - write-offs, sales, impairments (95,077 ) (164,407 ) (70 ) Balance, end of period $ 3,455,234 $ 3,132,078 $ 3,066,297 Accumulated depreciation Balance, beginning of period $ 560,837 $ 504,869 $ 413,394 Additions - depreciation 102,614 97,988 91,545 Deductions - write-offs, sales (1,268 ) (42,020 ) (70 ) Balance, end of period $ 662,183 $ 560,837 $ 504,869
ACC2 [Member]
Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation	28 years 183 days
ACC3 [Member]
Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation	29 years 292 days
ACC4 [Member]
Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation	30 years 292 days
ACC5 [Member]
Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation	29 years 256 days
ACC6 [Member]
Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation	30 years 256 days
ACC7 [Member]
Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation	32 years 183 days
CH1 [Member]
Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation	30 years 183 days
CH2 [Member]
Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation	30 years 256 days
SC1 Phase I and II [Member]
Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation	31 years 256 days
VA3 [Member]
Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation	30 years 183 days
VA4 [Member]
Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation	31 years 37 days

2. Significant Accounting Pol30

2. Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Basis of Presentation [Text Block]	Basis of Presentation This report combines the annual reports on Form 10-K for the year ended December 31, 2016 of DuPont Fabros Technology, Inc. and DuPont Fabros Technology, L.P. References to “DFT” mean DuPont Fabros Technology, Inc. and its controlled subsidiaries; and references to the “Operating Partnership” or “OP” mean DuPont Fabros Technology, L.P. and its controlled subsidiaries. We believe combining the annual reports on Form 10-K of DFT and the Operating Partnership into this single report provides the following benefits: • enhances investors’ understanding of DFT and the Operating Partnership by enabling investors to view the business as a whole in the same manner as management views and operates the business; • eliminates duplicative disclosure and provides a more streamlined and readable presentation since a substantial portion of the disclosure in this report applies to both DFT and the Operating Partnership; and • creates time and cost efficiencies through the preparation of one combined report instead of two separate reports. We operate DFT and the Operating Partnership as one business. The management of DFT consists of the same employees as the management of the Operating Partnership. We believe it is important for investors to understand the few differences between DFT and the Operating Partnership in the context of how DFT and the Operating Partnership operate as a consolidated company. DFT is a REIT, whose only material asset is its ownership of OP units of the Operating Partnership. As a result, DFT does not conduct business itself, other than acting as the sole general partner of the Operating Partnership, issuing public equity from time to time and guaranteeing unsecured debt of the Operating Partnership. DFT has not issued any indebtedness, but has guaranteed all of the unsecured debt of the Operating Partnership. The Operating Partnership, through its wholly-owned subsidiaries, holds all the real estate assets of the Company. Except for net proceeds from public equity issuances by DFT, which are contributed to the Operating Partnership in exchange for OP units or preferred units, the Operating Partnership generates all remaining capital required by our business. These sources include the Operating Partnership’s operations, its direct or indirect incurrence of indebtedness, and the issuance of partnership units. As sole general partner with control of the Operating Partnership, DFT consolidates the Operating Partnership for financial reporting purposes. The presentation of stockholders’ equity and partners’ capital are the main areas of difference between the consolidated financial statements of DFT and those of the Operating Partnership. The Operating Partnership’s capital includes preferred units and general and limited common units that are owned by DFT and the other partners. DFT’s stockholders’ equity includes preferred stock, common stock, additional paid in capital, retained earnings and accumulated other comprehensive income (loss). The common limited partnership interests held by the limited partners (other than DFT) in the Operating Partnership are presented as “redeemable partnership units” in the Operating Partnership’s consolidated financial statements and as “redeemable noncontrolling interests-operating partnership” in DFT’s consolidated financial statements. The only difference between the assets and liabilities of DFT and the Operating Partnership as of December 31, 2016 was a $4.2 million bank account held by DFT that is not part of the Operating Partnership. Net income is the same for DFT and the Operating Partnership. The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles, or GAAP. All significant intercompany accounts and transactions have been eliminated in the consolidated financial statements. We have one reportable segment consisting of investments in data centers located in the United States and Canada. All of our properties generate similar types of revenues and expenses related to customer rent and reimbursements and operating expenses. The delivery of our products is consistent across all properties and although services are provided to a range of customers, the types of services provided to them are limited to a few core principles. As such, the properties in our portfolio have similar economic characteristics and the nature of the products and services provided to our customers and the method to distribute such services are consistent throughout the portfolio.
Use of Estimates [Policy Text Block]	Use of Estimates The preparation of financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosures of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates.
Property [Policy Text Block]	Property All capital improvements for the income-producing properties are capitalized to individual building components, including interest and real estate taxes incurred during the period of development, and depreciated over their estimated useful lives. Interest is capitalized during the period of development based upon applying the property’s specific borrowing rate to the actual development costs expended up to specific borrowings, if any, and then applying our weighted-average borrowing rate to any residual development costs expended during the construction period. Interest is capitalized until the property has reached substantial completion and is ready for its intended use. Interest costs capitalized totaled $11.0 million , $12.3 million and $10.2 million for the years ended December 31, 2016 , 2015 and 2014 , respectively. We cease interest capitalization when a development is placed in service or temporarily suspended. We capitalize pre-development costs, including internal costs, incurred in pursuit of new development opportunities for which we believe future development is probable. Future development is dependent upon various factors, including zoning and regulatory approval, rental market conditions, construction costs and availability of capital. Pre-development costs incurred for which future development is not yet considered probable are expensed as incurred. In addition, if the status of such a pre-development opportunity changes, making future development no longer probable, any capitalized pre-development costs are written-off with a charge to expense. Furthermore, the revenue from incidental operations received from the current improvements in excess of any incremental costs are recorded as a reduction of total capitalized costs of the development project and not as a part of net income. The capitalization of costs during the development of assets (including interest and related loan fees, property taxes and other direct and indirect costs) begins when development efforts commence and ends when the asset, or a portion of the asset, is substantially complete and ready for its intended use. For the years ended December 31, 2016 , 2015 and 2014 , we capitalized $8.0 million , $7.5 million and $4.5 million , respectively, of internal development and leasing costs on all of our data centers. The fair value of in-place leases consists of the following components, as applicable: (1) the estimated cost to replace the leases, including foregone rents during the period of finding a new customer, foregone recovery of customer pass-through, customer improvements, and other direct costs associated with obtaining a new customer (referred to as tenant origination costs); (2) the estimated leasing commissions associated with obtaining a new customer (referred to as leasing commissions); and (3) the above/below market cash flow of the leases, determined by comparing the projected cash flows of the leases in place to projected cash flows of comparable market-rate leases (referred to as lease intangibles). Tenant origination costs are included in buildings and improvements in our accompanying consolidated balance sheets and are amortized as depreciation expense on a straight-line basis over the average remaining life of the underlying leases. Leasing commissions are classified as deferred costs and are amortized as amortization expense on a straight-line basis over the remaining life of the underlying leases. Lease intangible assets and liabilities are classified as lease contracts above and below market value, respectively, and amortized on a straight-line basis as decreases and increases, respectively, to rental revenue over the remaining life of the underlying leases. Should a customer terminate its lease early, the unamortized portions of leasing commissions and lease intangibles associated with that lease are written off to amortization expense or rental revenue, respectively, as further described below. Depreciation on buildings is generally provided on a straight-line basis over 40 years from the date the buildings were placed in service. Building components are depreciated over the life of the respective improvement ranging from 10 to 40 years from the date the components were placed in service. Personal property is depreciated over three years to seven years . Depreciation expense was $103.5 million , $98.8 million and $92.3 million for the years ended December 31, 2016 , 2015 and 2014 , respectively. Repairs and maintenance costs are expensed as incurred. We review each of our properties for indicators of impairment. Examples of such indicators may include a significant decrease in the market price of the property, a significant adverse change in the extent or manner in which the property is being used in its physical condition, a significant adverse change in legal factors or in the business climate that could affect the value of a property, including an adverse action or assessment by a regulator, an accumulation of costs significantly in excess of the amount originally expected for the development of a property, a history of operating or cash flow losses of the property or a current expectation that, more likely than not, a property will be sold or otherwise disposed of significantly before the end of its previously estimated useful life. When such impairment indicators exist, we review an estimate of the future undiscounted net cash flows expected to result from the real estate investment’s use and eventual disposition and compare that estimate to the carrying value of the property. We assess the recoverability of the carrying value of our assets on a property-by-property basis. We consider factors such as future operating income, trends and prospects, as well as the effects of leasing demand, competition, potential sales proceeds and other factors. If our undiscounted cash flow evaluation indicates that we are unable to recover the carrying value of a real estate investment, an impairment loss is recorded to the extent that the carrying value exceeds the estimated fair value of the property. No impairment losses were recorded for the years ended December 31, 2016 and 2014 . In the fourth quarter of 2015, we identified our NJ1 data center as an asset that fell outside of our strategic focus on wholesale data centers in our targeted markets, and it became evident that we would, more likely than not, sell NJ1 prior to its previously estimated useful life. In connection with that determination, we evaluated the recoverability of the carrying value for NJ1 and determined that its carrying value was no longer recoverable due to reducing its expected holding period. As a result, for the year ended December 31, 2015, we reduced the carrying value of NJ1 to its estimated fair value by recording an impairment charge of $122.5 million . Estimated fair value was determined using a third party appraisal for NJ1 in conjunction with the guidance in ASC 820, which involved the use of Level 3 inputs. The appraisal was based on the income capitalization approach which derives value using the property's potential income and an average market capitalization rate for comparable sales in the market. NJ1 was sold in the second quarter of 2016 at a gain of $22.8 million . We classify a data center property as held-for-sale when it meets the necessary criteria, which include when we commit to and actively embark on a plan to sell the asset, the sale is expected to be completed within one year under terms usual and customary for such sales, and actions required to complete the plan indicate that it is unlikely that significant changes to the plan will be made or that the plan will be withdrawn. Data center properties held-for-sale are carried at the lower of cost or fair value less costs to sell. Accordingly, as of December 31, 2016 and 2015 , we did not have any properties classified as held-for-sale.
Cash and Cash Equivalents, Policy [Policy Text Block]	Cash and Cash Equivalents We consider all demand deposits and money market accounts purchased with a maturity date of three months or less, at the date of purchase, to be cash equivalents. Our account balances at one or more institutions exceed the Federal Deposit Insurance Corporation (“FDIC”) insurance coverage and, as a result, there is a concentration of credit risk related to amounts on deposit in excess of FDIC insurance coverage. We have not experienced any losses and believe that the risk is not significant.
Deferred Costs [Policy Text Block]	Deferred Costs Deferred costs, net in our accompanying consolidated balance sheets include both financing and leasing costs. Financing costs, which represent fees and other costs incurred in obtaining debt, are amortized using the effective-interest rate method, or a method that approximates the effective-interest method, over the term of the loan and are included in amortization of deferred financing costs. Balances of financing costs for our unsecured revolving credit facility (the "Unsecured Credit Facility"), net of accumulated amortization, which are presented within deferred costs, net in our accompanying consolidated balance sheets at December 31, 2016 and 2015 , are as follows (in thousands): December 31, Financing costs presented within deferred costs, net 2016 2015 Financing costs $ 12,352 $ 8,198 Accumulated amortization (6,376 ) (4,969 ) Financing costs, net $ 5,976 $ 3,229 Balances of financing costs for our other recognized debt liabilities, net of accumulated amortization, which are presented as a reduction of each of the respective recognized debt liabilities in our accompanying consolidated balance sheets at December 31, 2016 and 2015 , are as follows (in thousands): December 31, Financing costs presented as a reduction of debt liability balances 2016 2015 Financing costs $ 20,423 $ 20,531 Accumulated amortization (7,935 ) (5,618 ) Financing costs, net $ 12,488 $ 14,913 On July 25, 2016, we amended and restated the Unsecured Credit Facility and the Unsecured Term Loan, which, due to the change in composition of lenders comprising the Unsecured Credit Facility's bank group, resulted in a loss on early extinguishment of debt of $1.2 million in the third quarter of 2016, which included a partial write-off of unamortized deferred financing costs of $0.5 million . In May 2014, we amended the Unsecured Credit Facility, which, due to the change in composition of lenders comprising the Unsecured Credit Facility's bank group, resulted in the partial write-off of unamortized deferred financing costs totaling $0.3 million . In July 2014, we amended the Unsecured Term Loan, which, due to the change in composition of lenders comprising the Unsecured Term Loan's bank group, resulted in a loss on early extinguishment of debt of $1.4 million , which included a partial write-off of unamortized deferred financing costs of $0.7 million . Leasing costs, which consist of external fees and costs incurred in the successful negotiation of leases, internal costs expended in the successful negotiation of leases and the estimated leasing commissions resulting from the allocation of the purchase price of ACC2, VA3, VA4 and ACC4, are deferred and amortized over the terms of the applicable leases on a straight-line basis. If an applicable lease terminates prior to the expiration of its initial term, the carrying amount of the leasing costs are written off to amortization expense. In June 2015, we wrote off $0.7 million of unamortized leasing costs to amortization expense related to a former customer in bankruptcy whose leases with us were rejected effective July 1, 2015 pursuant to an order made by the bankruptcy court, described below. Leasing costs incurred for the years ended December 31, 2016 , 2015 and 2014 are as follows (in thousands): Year ended December 31, 2016 2015 2014 Costs incurred for new leases $ 3,690 $ 2,096 $ 2,004 Costs incurred for renewals 202 1,188 153 Costs incurred for re-leases — 949 2,000 Total leasing costs incurred $ 3,892 $ 4,233 $ 4,157 Amortization of deferred leasing costs totaled $4.2 million , $4.9 million and $4.1 million for the years ended December 31, 2016 , 2015 and 2014 , respectively. Balances, net of accumulated amortization, at December 31, 2016 and 2015 are as follows (in thousands): December 31, 2016 2015 Leasing costs $ 53,556 $ 50,503 Accumulated amortization (33,756 ) (29,958 ) Leasing costs, net $ 19,800 $ 20,545
Inventory [Policy Text Block]	Inventory We maintain fuel inventory for our generators, which is recorded at the lower of cost (on a first-in, first-out basis) or market. As of December 31, 2016 and 2015 , the fuel inventory was $4.2 million and $4.5 million , respectively, and is included in prepaid expenses and other assets in the accompanying consolidated balance sheets.
Prepaid Rents [Policy Text Block]	Prepaid Rents Prepaid rents, typically prepayment of the following month’s rent, consist of payments received from customers prior to the time the payments are earned and are recognized as revenue in subsequent periods when earned.
Rental Income [Policy Text Block]	Rental Income We, as a lessor, have retained substantially all the risks and benefits of ownership and account for our leases as operating leases. For lease agreements that provide for scheduled fixed and determinable rent increases, rental income is recognized on a straight-line basis over the non-cancellable term of the lease, which commences when control of the space and critical power have been provided to the customer. If the lease contains an early termination clause with a penalty payment, we determine the lease termination date by evaluating whether the penalty reasonably assures that the lease will not be terminated early. Straight-line rents receivable are included in deferred rent, net in the accompanying consolidated balance sheets. Lease inducements, which include cash payments to customers, are amortized as a reduction of rental income over the noncancellable lease term. Lease inducements are included in prepaid expenses and other assets in the accompanying consolidated balance sheets. Lease intangible assets and liabilities that have resulted from above market and below market leases that were acquired are amortized on a straight-line basis as decreases and increases, respectively, to rental revenue over the remaining non-cancellable term of the underlying leases. If a lease terminates prior to the expiration of its initial term, the unamortized portion of straight-line rents receivable, lease inducements and lease intangibles associated with that lease will be written off to rental revenue. In June 2015, we wrote-off as a reduction of base rent $0.4 million of unreserved straight-line rents receivable, $0.1 million of unamortized lease inducements and $1.0 million of unamortized lease intangibles related to a former customer in bankruptcy whose leases with us were rejected effective July 1, 2015 pursuant to an order made by the bankruptcy court. Balances, net of accumulated amortization, at December 31, 2016 and 2015 are as follows (in thousands): December 31, 2016 2015 Lease contracts above market value $ 20,500 $ 20,500 Accumulated amortization (15,362 ) (14,471 ) Lease contracts above market value, net $ 5,138 $ 6,029 Lease contracts below market value $ 24,175 $ 24,175 Accumulated amortization (21,345 ) (20,043 ) Lease contracts below market value, net $ 2,830 $ 4,132 Our policy is to record an allowance for losses on accounts receivable equal to the estimated uncollectible accounts. The estimate is based on our historical experience and a review of the current status of our receivables. As of December 31, 2016 , we had a note receivable from a former customer of $25.0 million , which resulted from the settlement of our claim in this former customer's bankruptcy proceedings in the fourth quarter of 2016 and replaced the $6.5 million note receivable that we had from this former customer as of December 31, 2015 . We are accounting for the note receivable on a non-accrual basis. As of December 31, 2016 and 2015 , we had allowances against these notes of $23.6 million and $5.1 million , respectively, leaving a note receivable, net, of $1.4 million as of December 31, 2016 and 2015 , which is included within rents and other receivables, net in our accompanying consolidated balance sheets. Based on the principal payment schedule in the note that includes semiannual principal payments beginning in June 2017, we continue to be reasonably assured that we will be able to collect the balance of the note receivable, net. We also establish an appropriate allowance for doubtful accounts for receivables arising from the straight-lining of rents. These receivables arise from revenue recognized in excess of amounts currently due under the lease and are recorded as deferred rent in the accompanying consolidated balance sheets. As of December 31, 2016 and 2015 , we had no material allowances. Our customer leases generally contain provisions under which the customers reimburse us for a portion of operating expenses and real estate taxes incurred by the property. Recoveries from tenants are included in revenue in the accompanying consolidated statements of operations in the period the applicable expenditures are incurred. The majority of our customer leases also provide us with a property management fee based on a percentage of base rent collected and property-level operating expenses, other than charges for power used by customers to run their servers and cool their space. Property management fees are included in base rent in the accompanying consolidated statements of operations in the applicable period in which they are earned.
Other Revenue [Policy Text Block]	Other Revenue Other revenue primarily consists of services provided to customers on a non-recurring basis. This includes layout design and installation of electrical power circuits, data cabling, server cabinets and racks, computer room airflow analyses and monitoring and other services requested by customers. Revenue is recognized on a completed contract basis when the project is finished and ready for the customer's use. This method is consistently applied for all periods presented. Costs of providing these services are included in other expenses in the accompanying consolidated statements of operations.
Income Tax, Policy [Policy Text Block]	Income Taxes DFT elected to be taxed as a REIT under the Internal Revenue Code of 1986, as amended (the “Code”), commencing with the taxable year ended December 31, 2007. In general, a REIT that meets certain organizational and operational requirements and distributes at least 90 percent of its REIT taxable income to its shareholders in a year will not be subject to income tax to the extent of the income it distributes. We currently qualify and intend to continue to qualify as a REIT under the Code. As a result, no provision for federal income taxes on income from continuing operations is required, except for taxes on certain property sales and on income, if any, of DF Technical Services, LLC, our taxable REIT subsidiary (“TRS”). If we fail to qualify as a REIT in any taxable year, we will be subject to federal income tax (including any applicable alternative minimum tax) on our income at regular corporate tax rates for the year in which we do not qualify and the succeeding four years. Although we expect to qualify for taxation as a REIT, we may be subject to state and local income and franchise taxes and to federal income and excise taxes on any undistributed income. As of December 31, 2016 and 2015 , we did not have any unrecognized tax benefits. We do not believe that there will be any material changes in our unrecognized tax positions over the next 12 months. We are subject to examination by the respective taxing authorities for the tax years 2013 through 2016. In general, a TRS may perform non-customary services for customers, hold assets that DFT cannot hold directly and generally may engage in any real estate or non real estate-related business. A TRS is subject to corporate federal and state income taxes on its taxable income at regular statutory tax rates. For the years ended December 31, 2016 and 2014, we incurred $0.1 million of income taxes. For the year ended December 31, 2015, we incurred no income taxes; however, we recorded a deferred income tax credit of $0.2 million to reverse the cumulative deferred tax expense recorded as of December 31, 2014. We account for income taxes using the asset and liability method under which deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Valuation allowances are provided if, based upon the weight of the available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. As of December 31, 2016 , our TRS had a deferred tax asset of $0.2 million , comprised entirely of its net operating loss carryforward, and no deferred tax liability, resulting in a net deferred tax asset of $0.2 million . We recorded a full valuation allowance for this net deferred tax asset as of December 31, 2016 due to the uncertainty of the realizability of this asset. The net operating loss carryforward of $0.2 million will begin to expire in 2031 if not utilized by then. As of December 31, 2015 , our TRS had a deferred tax asset of $4.6 million , comprised entirely of its net operating loss carryforward, and a deferred tax liability of $2.3 million , primarily comprised of a temporary depreciation difference, resulting in a net deferred tax asset of $2.3 million . We recorded a full valuation allowance for this net deferred tax asset as of December 31, 2015 due to the uncertainty of the realizability of this asset.
Redeemable Noncontrolling Interests—Operating Partnership / Redeemable Partnership Units [Policy Text Block]	Redeemable Noncontrolling Interests – Operating Partnership / Redeemable Partnership Units Redeemable noncontrolling interests – operating partnership, as presented on DFT’s consolidated balance sheets, represent the limited partnership interests in the Operating Partnership (the “OP units”) held by individuals and entities other than DFT. These interests are also presented on the Operating Partnership’s consolidated balance sheets, referred to as “redeemable partnership units.” Accordingly, the following discussion related to redeemable noncontrolling interests – operating partnership of DFT refers equally to redeemable partnership units of the Operating Partnership. Redeemable noncontrolling interests – operating partnership, which require cash payment, or allow settlement in shares, but with the ability to deliver the shares outside of the control of DFT, are reported outside of the permanent equity section of the consolidated balance sheets of DFT and the Operating Partnership. Redeemable noncontrolling interests – operating partnership are adjusted for income, losses and distributions allocated to OP units not held by DFT (normal noncontrolling interest accounting amount). Adjustments to redeemable noncontrolling interests – operating partnership are recorded to reflect increases or decreases in the ownership of the Operating Partnership by holders of OP units, including the redemptions of OP units for cash or in exchange for shares of DFT’s common stock. If such adjustments result in redeemable noncontrolling interests – operating partnership being recorded at less than the redemption value of the OP units, redeemable noncontrolling interests – operating partnership are further adjusted to their redemption value. See Note 9. Redeemable noncontrolling interests – operating partnership are recorded at the greater of the normal noncontrolling interest accounting amount or redemption value. The following is a summary of activity for redeemable noncontrolling interests – operating partnership for the years ended December 31, 2016 , 2015 and 2014 (dollars in thousands): OP Units Number Amount Balance at December 31, 2013 15,671,537 $ 387,244 Net income attributable to redeemable noncontrolling interests – operating partnership — 18,704 Distributions declared — (22,831 ) Redemption of operating partnership units (234,300 ) (6,100 ) Adjustments to redeemable noncontrolling interests – operating partnership — 136,117 Balance at December 31, 2014 15,437,237 $ 513,134 Net loss attributable to redeemable noncontrolling interests – operating partnership — (5,993 ) Distributions declared — (26,513 ) Redemption of operating partnership units (363,674 ) (9,544 ) Adjustments to redeemable noncontrolling interests – operating partnership — 8,105 Balance at December 31, 2015 15,073,563 $ 479,189 Net income attributable to redeemable noncontrolling interests – operating partnership — 24,248 Other comprehensive loss attributable to redeemable noncontrolling interests – operating partnership — (201 ) Distributions declared — (26,723 ) Redemption of operating partnership units (1,618,048 ) (64,169 ) Adjustments to redeemable noncontrolling interests – operating partnership — 178,757 Balance at December 31, 2016 13,455,515 $ 591,101 The following is a summary of activity for redeemable partnership units for the years ended December 31, 2016 , 2015 and 2014 (dollars in thousands): OP Units Number Amount Balance at December 31, 2013 15,671,537 $ 387,244 Redemption of operating partnership units (234,300 ) (6,100 ) Adjustments to redeemable partnership units — 131,990 Balance at December 31, 2014 15,437,237 $ 513,134 Redemption of operating partnership units (363,674 ) (9,544 ) Adjustments to redeemable partnership units — (24,401 ) Balance at December 31, 2015 15,073,563 $ 479,189 Redemption of operating partnership units (1,618,048 ) (64,169 ) Adjustments to redeemable partnership units — 176,081 Balance at December 31, 2016 13,455,515 $ 591,101 Net income is allocated to controlling interests and redeemable noncontrolling interests – operating partnership in accordance with the limited partnership agreement of the Operating Partnership. The following is a summary of net income attributable to controlling interests and transfers to redeemable noncontrolling interests – operating partnership for the years ended December 31, 2016 , 2015 and 2014 (dollars in thousands): Year ended December 31, 2016 2015 2014 Net income attributable to controlling interests $ 157,199 $ 1,907 $ 105,907 Transfers from noncontrolling interests: Net change in the Company’s common stock and additional paid in capital due to the redemption of OP units and other adjustments to redeemable noncontrolling interests – operating partnership (114,588 ) 1,439 (130,017 ) $ 42,611 $ 3,346 $ (24,110 )
Earnings Per Share of the REIT [Policy Text Block]	Earnings Per Share of DFT Basic earnings per share is calculated by dividing the net income attributable to common shares for the period by the weighted average number of common shares outstanding during the period using the two class method. Diluted earnings per share is calculated by dividing the net income attributable to common shares for the period by the weighted average number of common and dilutive securities outstanding during the period using the two class method.
Earnings Per Unit of the Operating Partnership [Policy Text Block]	Earnings Per Unit of the Operating Partnership Basic earnings per unit is calculated by dividing the net income attributable to common units for the period by the weighted average number of common units outstanding during the period using the two class method. Diluted earnings per unit is calculated by dividing the net income attributable to common units for the period by the weighted average number of common and dilutive securities outstanding during the period using the two class method.
Stock-based Compensation [Policy Text Block]	Stock-based Compensation We periodically award stock-based compensation to employees and members of our Board of Directors in the form of common stock, restricted common stock, options and performance units. For each common stock award granted by DFT, the OP issues an equivalent common unit, which may be referred to herein as a common share, common stock, or a common unit. We estimate the fair value of the awards and recognize this value over the requisite service period. The fair value of restricted stock-based compensation is based on the market value of DFT’s common stock on the date of the grant. The fair value of options to purchase common stock is based on the Black-Scholes model. The fair value of performance units is based on a Monte Carlo simulation. Forfeitures of all stock-based compensation awards are recognized as they occur. Compensation paid with Company common shares, which is included in general and administrative expense on our consolidated statements of operations, totaled $6.6 million , $5.3 million and $6.2 million for the years ended December 31, 2016 , 2015 and 2014 , respectively. We capitalized $0.9 million , $0.8 million and $0.7 million of compensation paid with Company common shares to our data centers under development for the years ended December 31, 2016 , 2015 and 2014 , respectively.
Foreign Currency Transactions and Translations Policy [Policy Text Block]	Foreign Currency The U.S. dollar is the functional currency of our consolidated operations in the United States. The functional currency of our consolidated entities that operate outside of the United States is the principal currency of the economic environment in which the entity primarily generates and expends cash. We translate the financial statements of consolidated entities whose functional currency is not the U.S. dollar into U.S. dollars. We translate assets and liabilities at the exchange rate in effect as of the financial statement date and translate income statement accounts using the weighted average exchange rate for the period. We include foreign currency translation adjustments and the effect of exchange rate changes on intercompany transactions of a long-term investment nature as a separate component of stockholders' equity or partners' capital. We report gains and losses from the effect of rate changes on intercompany receivables and payables that are not of a long-term investment nature, as well as gains and losses from remeasuring U.S. dollar transactions for non-U.S. functional currency entities, in other expenses on our consolidated statements of operations. For the year ended December 31, 2016 , we had less than $0.1 million of foreign currency transaction losses.
New Accounting Pronouncements, Policy [Policy Text Block]	Recently Issued Accounting Pronouncements Revenue Recognition - In May 2014, the Financial Accounting Standards Board, or FASB, issued Accounting Standard Update No. 2014-09, Revenue from Contracts with Customers (Topic 606). The standard’s core principle is that a company will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. We are required to apply the new standard in the first quarter of 2018 and expect to elect the modified retrospective method of application of the standard. Although the standard does not apply to leases, we have assessed the impact on our financial position and results of operations. The standard will change our method of recognizing revenue on service and installation contracts included in other revenue in the accompanying consolidated statements of operations from the completed contract method to a method that recognizes revenue over the course of the contract based on the goods or services transferred to date relative to the remaining goods or services promised under the contract. We do not expect that this change will have a material effect on our financial position or results of operations. In addition, we currently do not believe the standard will have a material impact on how we recognize revenues from tenants with respect to operating expense recoveries on our financial position or results of operations. Leases - In February 2016, the FASB issued Accounting Standards Update No. 2016-02 - Leases (Topic 842). We are required to apply the new standard in the first quarter of 2019. The Company’s leases consist of both lease components that will be accounted for under this standard and non-lease components such as operating expense recovery income that will be accounted for under ASU 2014-09, Revenue from Contracts with Customers. The standard does not fundamentally change the lessor accounting model, and we do not believe that the new standard will have a material impact on our financial position or results of operations. Financial Instruments - In June 2016, the FASB issued Accounting Standards Update No. 2016-13, Financial Instruments - Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments. Under this guidance, a company will be required to use a new forward-looking "expected loss" model for trade and other receivables that generally will result in the earlier recognition of allowances for losses. We are required to apply the new standard in the first quarter of 2020 and do not believe that the new standard will have a material effect on our financial position or results of operations. Statement of Cash Flows - In August 2016, the FASB issued Accounting Standards Update No. 2016-15, Statement of Cash Flows (Topic 230), Classification of Certain Cash Receipts and Cash Payments. The standard provides guidance on eight specific cash flow classification issues including debt prepayment or debt extinguishment costs, contingent consideration payments made after a business combination, and separately identifiable cash flows and application of the predominance principle. We are required to apply the new standard in the first quarter of 2018 and do not believe that the new standard will have a material effect on our financial position or results of operations. Statement of Cash Flows - Restricted Cash - In November 2016, the FASB issued Accounting Standards Update No. 2016-18 (Topic 230), Restricted Cash. The standard requires restricted cash to be included with cash and cash equivalents when reconciling the beginning and ending amounts in the statement of cash flows. We are required to apply the new standard in the first quarter of 2018 and do not believe that the new standard will have a material effect on our financial position or results of operations. Business Combinations - In January 2017, the FASB issued Accounting Standards Update No. 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business. The standard narrows the existing definition of a business and provides a framework for evaluating whether a transaction should be accounted for as an acquisition of assets or a business. The guidance is effective for public entities for fiscal years beginning after December 15, 2017 and interim periods within those years. However, we will early-adopt the standard effective January 1, 2017. As a result of this new guidance, acquisitions may now result in an asset purchase rather than a business combination. We do not believe that the new standard will have a material effect on our financial position or results of operations. Recently Adopted Accounting Pronouncements Going Concern - In August 2014, the FASB issued Accounting Standards Update No. 2014-15 - Presentation of Financial Statements - Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern. Under this guidance, management is required to perform a going concern evaluation similar to the auditor's evaluation required by standards issued by the Public Company Accounting Oversight Board and the American Institute of Certified Public Accountants. This evaluation is required for both annual and interim reporting periods. We adopted the new standard in the fourth quarter of 2016, and there was no material effect on our financial position or results of operations. Consolidation - In February 2015, the FASB issued Accounting Standards Update No. 2015-02 - Consolidation: Amendments to the Consolidation Analysis, which amends the criteria for determining variable interest entities (“VIEs”), amends the criteria for determining if a service provider possesses a variable interest in a VIE, and eliminates the presumption that a general partner should consolidate a limited partnership. We adopted this standard as of January 1, 2016, and there was no material effect on our financial position or results of operations. Stock Compensation - In March 2016, the FASB issued Accounting Standards Update No. 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. The new guidance affects two areas of our accounting. First, the guidance increases the amount an employer can withhold to cover income taxes on awards and still qualify for the exception to liability classification for shares used to satisfy the employer's statutory income tax withholding obligation. An employer is now allowed to withhold shares up to the amount of tax potentially owed using the maximum statutory tax rate in each jurisdiction. Second, companies now have the ability to make a policy election to account for forfeitures as they occur versus recording a forfeiture estimate. We early-adopted this standard as of January 1, 2016 and elected to account for forfeitures as they occur versus recording a forfeiture estimate. Per the guidance, we used a modified retrospective transition method of adoption, with a cumulative effect adjustment to accumulated deficit on our consolidated balance sheet as of December 31, 2015 totaling less than $0.1 million (see below). Change in Accounting Principle Stock Compensation - As required by Accounting Standards Update No. 2016-09 issued in March 2016, described above, we made a cumulative-effect adjustment to accumulated deficit to eliminate the forfeiture estimate recorded as of December 31, 2015, with a corresponding adjustment to additional paid in capital. The following table presents the prior period amounts that have been impacted by the new guidance and retrospectively adjusted on the consolidated balance sheet as of December 31, 2015 for DFT (dollars in thousands): As of December 31, 2015 As Previously Reported Impact of Change in Accounting Principle As Adjusted and Currently Reported Additional paid in capital $ 684,968 $ 74 $ 685,042 Accumulated deficit (79,871 ) (74 ) (79,945 ) Because the consolidated balance sheet for the Operating Partnership includes capital accounts for the general partner and the limited partners, which each include a combination of partner capital and retained earnings (accumulated deficit), there was no adjustment required for the consolidated balance sheet for the Operating Partnership as of December 31, 2015.

2. Significant Accounting Pol31

2. Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Schedule of Deferred Financing Costs [Table Text Block]	Balances of financing costs for our unsecured revolving credit facility (the "Unsecured Credit Facility"), net of accumulated amortization, which are presented within deferred costs, net in our accompanying consolidated balance sheets at December 31, 2016 and 2015 , are as follows (in thousands): December 31, Financing costs presented within deferred costs, net 2016 2015 Financing costs $ 12,352 $ 8,198 Accumulated amortization (6,376 ) (4,969 ) Financing costs, net $ 5,976 $ 3,229 Balances of financing costs for our other recognized debt liabilities, net of accumulated amortization, which are presented as a reduction of each of the respective recognized debt liabilities in our accompanying consolidated balance sheets at December 31, 2016 and 2015 , are as follows (in thousands): December 31, Financing costs presented as a reduction of debt liability balances 2016 2015 Financing costs $ 20,423 $ 20,531 Accumulated amortization (7,935 ) (5,618 ) Financing costs, net $ 12,488 $ 14,913
Schedule of Leasing Costs Incurred [Table Text Block]	Leasing costs incurred for the years ended December 31, 2016 , 2015 and 2014 are as follows (in thousands): Year ended December 31, 2016 2015 2014 Costs incurred for new leases $ 3,690 $ 2,096 $ 2,004 Costs incurred for renewals 202 1,188 153 Costs incurred for re-leases — 949 2,000 Total leasing costs incurred $ 3,892 $ 4,233 $ 4,157
Schedule of Deferred Leasing Costs [Table Text Block]	Balances, net of accumulated amortization, at December 31, 2016 and 2015 are as follows (in thousands): December 31, 2016 2015 Leasing costs $ 53,556 $ 50,503 Accumulated amortization (33,756 ) (29,958 ) Leasing costs, net $ 19,800 $ 20,545
Schedule of Lease Intangibles Above and Below Market Value [Table Text Block]	Balances, net of accumulated amortization, at December 31, 2016 and 2015 are as follows (in thousands): December 31, 2016 2015 Lease contracts above market value $ 20,500 $ 20,500 Accumulated amortization (15,362 ) (14,471 ) Lease contracts above market value, net $ 5,138 $ 6,029 Lease contracts below market value $ 24,175 $ 24,175 Accumulated amortization (21,345 ) (20,043 ) Lease contracts below market value, net $ 2,830 $ 4,132
Redeemable Noncontrolling Interest [Table Text Block]	The following is a summary of activity for redeemable noncontrolling interests – operating partnership for the years ended December 31, 2016 , 2015 and 2014 (dollars in thousands): OP Units Number Amount Balance at December 31, 2013 15,671,537 $ 387,244 Net income attributable to redeemable noncontrolling interests – operating partnership — 18,704 Distributions declared — (22,831 ) Redemption of operating partnership units (234,300 ) (6,100 ) Adjustments to redeemable noncontrolling interests – operating partnership — 136,117 Balance at December 31, 2014 15,437,237 $ 513,134 Net loss attributable to redeemable noncontrolling interests – operating partnership — (5,993 ) Distributions declared — (26,513 ) Redemption of operating partnership units (363,674 ) (9,544 ) Adjustments to redeemable noncontrolling interests – operating partnership — 8,105 Balance at December 31, 2015 15,073,563 $ 479,189 Net income attributable to redeemable noncontrolling interests – operating partnership — 24,248 Other comprehensive loss attributable to redeemable noncontrolling interests – operating partnership — (201 ) Distributions declared — (26,723 ) Redemption of operating partnership units (1,618,048 ) (64,169 ) Adjustments to redeemable noncontrolling interests – operating partnership — 178,757 Balance at December 31, 2016 13,455,515 $ 591,101
Redeemable Partnership Units [Table Text Block]	The following is a summary of activity for redeemable partnership units for the years ended December 31, 2016 , 2015 and 2014 (dollars in thousands): OP Units Number Amount Balance at December 31, 2013 15,671,537 $ 387,244 Redemption of operating partnership units (234,300 ) (6,100 ) Adjustments to redeemable partnership units — 131,990 Balance at December 31, 2014 15,437,237 $ 513,134 Redemption of operating partnership units (363,674 ) (9,544 ) Adjustments to redeemable partnership units — (24,401 ) Balance at December 31, 2015 15,073,563 $ 479,189 Redemption of operating partnership units (1,618,048 ) (64,169 ) Adjustments to redeemable partnership units — 176,081 Balance at December 31, 2016 13,455,515 $ 591,101
Schedule of Net Income Attributable to Controlling Interests and Transfers From Redeemable Noncontrolling Interests Operating Partnership [Table Text Block]	The following is a summary of net income attributable to controlling interests and transfers to redeemable noncontrolling interests – operating partnership for the years ended December 31, 2016 , 2015 and 2014 (dollars in thousands): Year ended December 31, 2016 2015 2014 Net income attributable to controlling interests $ 157,199 $ 1,907 $ 105,907 Transfers from noncontrolling interests: Net change in the Company’s common stock and additional paid in capital due to the redemption of OP units and other adjustments to redeemable noncontrolling interests – operating partnership (114,588 ) 1,439 (130,017 ) $ 42,611 $ 3,346 $ (24,110 )
New Accounting Pronouncement, Early Adoption [Table Text Block]	The following table presents the prior period amounts that have been impacted by the new guidance and retrospectively adjusted on the consolidated balance sheet as of December 31, 2015 for DFT (dollars in thousands): As of December 31, 2015 As Previously Reported Impact of Change in Accounting Principle As Adjusted and Currently Reported Additional paid in capital $ 684,968 $ 74 $ 685,042 Accumulated deficit (79,871 ) (74 ) (79,945 )

3. Real Estate Assets (Tables)

3. Real Estate Assets (Tables)	12 Months Ended
	Dec. 31, 2016
Real Estate [Abstract]
Schedule of Real Estate Properties [Table Text Block]	The following is a summary of our properties as of December 31, 2016 (dollars in thousands): Property Location Land Buildings and Improvements Construction in Progress and Land Held for Development Total Cost (2) ACC2 Ashburn, VA $ 2,500 $ 156,480 $ 158,980 ACC3 Ashburn, VA 1,071 96,080 97,151 ACC4 Ashburn, VA 6,600 538,869 545,469 ACC5 Ashburn, VA 6,443 299,016 305,459 ACC6 Ashburn, VA 5,518 216,829 222,347 ACC7 Ashburn, VA 9,753 332,970 342,723 CH1 Elk Grove Village, IL 23,611 359,171 382,782 CH2 Elk Grove Village, IL 14,392 256,539 270,931 SC1 Phases I-II Santa Clara, CA 20,202 433,099 453,301 VA3 Reston, VA 9,000 179,694 188,694 VA4 Bristow, VA 6,800 149,614 156,414 105,890 3,018,361 — 3,124,251 Construction in progress and land held for development (1) 330,983 330,983 $ 105,890 $ 3,018,361 $ 330,983 $ 3,455,234 (1) Properties located in Ashburn, VA (ACC8, ACC9, ACC10, and ACC11), Elk Grove Village, IL (CH3), Santa Clara, CA (SC1 Phase III, formerly referred to as SC2), Hillsboro, OR (OR1 and OR2) and Vaughan, ON (TOR1). (2) As of December 31, 2016, the total cost of long-lived assets located in the United States totaled $3,408.9 million , and the total costs of long-lived assets located in Canada totaled $46.3 million (TOR1 in Vaughan, ON).
Major Components Of Properties And Useful Lives [Table Text Block]	The following presents the major components of our properties and the useful lives over which they are depreciated: Component Component Life (years) Land N/A Building improvements 40 Electrical infrastructure—power distribution units 20 Electrical infrastructure—uninterrupted power supply 25 Electrical infrastructure—switchgear/transformers 30 Fire protection 40 Security systems 20 Mechanical infrastructure—heating, ventilating and air conditioning 20 Mechanical infrastructure—chiller pumps/building automation 25 Mechanical infrastructure—chilled water storage and pipes 30

4. Intangible Assets and Liab33

4. Intangible Assets and Liabilities (Tables)	12 Months Ended
	Dec. 31, 2016
Leasing Costs [Member]
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]	As of December 31, 2016 , these assets have a weighted average remaining life of 6.9 years with estimated future amortization as follows (in thousands): Year Ending December 31, 2017 $ 4,200 2018 3,854 2019 2,778 2020 2,235 2021 1,752 2022 and thereafter 4,981 $ 19,800
Lease Contracts [Member]
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]	As of December 31, 2016 , our net lease intangible assets have a weighted average remaining life of 6.9 years for above market leases and 3.5 years for below market leases with estimated net future amortization (as an increase (decrease) to rental income) as follows (in thousands): Year Ending December 31, 2017 $ 467 2018 35 2019 (480 ) 2020 (644 ) 2021 (570 ) 2022 and thereafter (1,116 ) $ (2,308 )
Tenant Origination Costs [Member]
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]	As of December 31, 2016 , these assets have a weighted average remaining life of 1.6 years with estimated future amortization as follows (in thousands): Year Ending December 31, 2017 $ 1,243 2018 746 $ 1,989

5. Leases (Tables)

5. Leases (Tables)	12 Months Ended
	Dec. 31, 2016
Leases [Abstract]
Schedule Of Customers Comprising More Than Ten Percent Of Consolidated Revenues [Table Text Block]	For the years ended December 31, 2016 , 2015 and 2014 , the following customers comprised more than 10.0% of our consolidated revenues: Microsoft Facebook Fortune 25 Investment Grade-Rated Company Year ended December 31, 2016 29.7 % 17.6 % 10.3 % Year ended December 31, 2015 25.2 % 16.9 % 6.5 % Year ended December 31, 2014 21.6 % 17.4 % 4.7 %
Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]	As of December 31, 2016 , future minimum lease payments to be received under noncancellable operating leases are as follows for the years ending December 31 (in thousands): 2017 $ 365,642 2018 358,439 2019 292,355 2020 239,842 2021 219,023 2022 and thereafter 751,080 $ 2,226,381

6. Debt (Tables)

6. Debt (Tables)	12 Months Ended
	Dec. 31, 2016
Debt Instrument [Line Items]
Schedule of Debt [Table Text Block]	Debt Summary as of December 31, 2016 and December 31, 2015 ($ in thousands) December 31, 2016 December 31, 2015 Amounts (1) % of Total Rates Maturities (years) Amounts (1) Secured $ 111,250 9 % 2.3 % 1.2 $ 115,000 Unsecured 1,150,926 91 % 4.9 % 5.1 1,100,000 Total $ 1,262,176 100 % 4.7 % 4.8 $ 1,215,000 Fixed Rate Debt: Unsecured Notes due 2021 $ 600,000 47 % 5.9 % 4.7 $ 600,000 Unsecured Notes due 2023 (2) 250,000 20 % 5.6 % 6.5 250,000 Fixed Rate Debt $ 850,000 67 % 5.8 % 5.2 $ 850,000 Floating Rate Debt: Unsecured Credit Facility 50,926 4 % 2.4 % 3.6 — Unsecured Term Loan 250,000 20 % 2.3 % 5.1 250,000 ACC3 Term Loan 111,250 9 % 2.3 % 1.2 115,000 Floating Rate Debt 412,176 33 % 2.3 % 3.8 365,000 Total $ 1,262,176 100 % 4.7 % 4.8 $ 1,215,000 (1) Principal amounts exclude deferred financing costs. (2) Principal amount shown excludes original issue discount of $1.7 million .
Schedule of Maturities of Long-term Debt [Table Text Block]	A summary of our debt repayment schedule as of December 31, 2016 is as follows: Debt Maturity as of December 31, 2016 ($ in thousands) Year Fixed Rate (1) Floating Rate (1) Total (1) % of Total Rates 2017 — 8,750 (4) 8,750 0.7 % 2.3 % 2018 — 102,500 (4) 102,500 8.1 % 2.3 % 2019 — — — — % — % 2020 — 50,926 (5) 50,926 4.1 % 2.4 % 2021 600,000 (2) — 600,000 47.5 % 5.9 % 2022 — 250,000 (6) 250,000 19.8 % 2.3 % 2023 250,000 (3) — 250,000 19.8 % 5.6 % Total $ 850,000 $ 412,176 $ 1,262,176 100 % 4.7 % (1) Principal amounts exclude deferred financing costs. (2) The 5.875% Unsecured Notes due 2021 mature on September 15, 2021 . (3) The 5.625% Unsecured Notes due 2023 mature on June 15, 2023 . Principal amount excludes original issue discount of $1.7 million as of December 31, 2016 . (4) The ACC3 Term Loan matures on March 27, 2018 with no extension option. Quarterly principal payments of $1.25 million began on April 1, 2016 , increase to $2.5 million on April 1, 2017 and continue through maturity. (5) The Unsecured Credit Facility matures on July 25, 2020 with a one-year extension option. (6) The Unsecured Term Loan matures on January 21, 2022 with no extension option.
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Schedule Of Line of Credit Interest Rate Margin Applicable By Indebtedness Level [Table Text Block]	Prior to our receiving an investment grade credit rating, the applicable margin added to LIBOR and the base rate is based on the table below. Applicable Margin Pricing Level Ratio of Total Indebtedness to Gross Asset Value LIBOR Rate Loans Base Rate Loans Level 1 Less than or equal to 35% 1.55 % 0.55 % Level 2 Greater than 35% but less than or equal to 40% 1.65 % 0.65 % Level 3 Greater than 40% but less than or equal to 45% 1.80 % 0.80 % Level 4 Greater than 45% but less than or equal to 52.5% 1.95 % 0.95 % Level 5 Greater than 52.5% 2.15 % 1.15 %
Schedule Of Credit Rating for Line of Credit [Table Text Block]	In the event we receive an investment grade credit rating, borrowings under the Unsecured Credit Facility will bear interest based on the table below. Applicable Margin Credit Rating Level Credit Rating LIBOR Rate Loans Base Rate Loans Level 1 Greater than or equal to A- by S&P or A3 by Moody’s 0.85 % 0.00 % Level 2 Greater than or equal to BBB+ by S&P or Baa1 by Moody’s 0.90 % 0.00 % Level 3 Greater than or equal to BBB by S&P or Baa2 by Moody’s 1.00 % 0.00 % Level 4 Greater than or equal to BBB- by S&P or Baa3 by Moody’s 1.20 % 0.20 % Level 5 Less than BBB- by S&P or Baa3 by Moody’s 1.55 % 0.55 %
Unsecured Term Loan [Member]
Debt Instrument [Line Items]
Schedule Of Term Loan Interest Rate Margin Applicable By Indebtedness Level [Table Text Block] [Table Text Block]	Prior to our receiving an investment grade credit rating, the applicable margin added to LIBOR and the base rate is based on the table below. Applicable Margin Pricing Level Ratio of Total Indebtedness to Gross Asset Value LIBOR Rate Loans Base Rate Loans Level 1 Less than or equal to 35% 1.50 % 0.50 % Level 2 Greater than 35% but less than or equal to 40% 1.60 % 0.60 % Level 3 Greater than 40% but less than or equal to 45% 1.75 % 0.75 % Level 4 Greater than 45% but less than or equal to 52.5% 1.90 % 0.90 % Level 5 Greater than 52.5% 2.10 % 1.10 %
Schedule Of Credit Rating For Unsecured Term Loan [Table Text Block] [Table Text Block]	The terms of the Unsecured Term Loan also provide that, in the event we receive an investment grade credit rating, borrowings under the loan will bear interest based on the table below. Applicable Margin Credit Rating Level Credit Rating LIBOR Rate Loans Base Rate Loans Level 1 Greater than or equal to A- by S&P or A3 by Moody’s 0.825 % 0.00 % Level 2 Greater than or equal to BBB+ by S&P or Baa1 by Moody’s 0.875 % 0.00 % Level 3 Greater than or equal to BBB by S&P or Baa2 by Moody’s 1.00 % 0.00 % Level 4 Greater than or equal to BBB- by S&P or Baa3 by Moody’s 1.25 % 0.25 % Level 5 Less than BBB- by S&P or Baa3 by Moody’s 1.65 % 0.65 %
Unsecured Notes due 2021 [Member]
Debt Instrument [Line Items]
Debt Instrument Redemption [Table Text Block]	The Unsecured Notes due 2021 may be redeemed at the Operating Partnership's option, in whole or in part, at any time, at the following redemption prices (expressed as percentages of the principal amount thereof) if redeemed during the 12-month period commencing September 15 of the years indicated below, in each case together with accrued and unpaid interest to the date of redemption: Year Redemption Price 2016 104.406 % 2017 102.938 % 2018 101.469 % 2019 and thereafter 100.000 %
Unsecured Notes due 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument Redemption [Table Text Block]	The Unsecured Notes due 2023 may be redeemed at the Operating Partnership's option, in whole or in part, at any time, on and after June 15, 2018 at the following redemption prices (expressed as percentages of the principal amount thereof) if redeemed during the 12-month period commencing June 15 of the years indicated below, in each case together with accrued and unpaid interest to the date of redemption: Year Redemption Price 2018 104.219 % 2019 102.813 % 2020 101.406 % 2021 and thereafter 100.000 %

10. Preferred Stock (Tables)

10. Preferred Stock (Tables)	12 Months Ended
	Dec. 31, 2016
Series A Preferred Stock [Member]
Preferred Stock Dividend [Line Items]
Schedule of Preferred Stock Dividend [Table Text Block]	For the year ended December 31, 2014 , DFT declared and paid the following cash dividends on its Series A Preferred Stock, of which the OP paid an equivalent distribution on its preferred units: Record Date Payment Date Cash Dividend Ordinary Taxable Dividend (Unaudited) Nontaxable Return of Capital Distributions (Unaudited) 4/4/2014 4/15/2014 $ 0.4921875 $ 0.4921875 $ 0.00 7/3/2014 7/15/2014 0.4921875 0.4921875 0.00 10/3/2014 10/15/2014 0.4921875 0.4921875 0.00 12/30/2014 1/15/2015 0.4921875 0.4921875 0.00 $ 1.9687500 $ 1.9687500 $ 0.00 For the year ended December 31, 2015 , DFT declared and paid the following cash dividends on its Series A Preferred Stock, of which the OP paid an equivalent distribution on its preferred units: Record Date Payment Date Cash Dividend Ordinary Taxable Dividend (Unaudited) Nontaxable Return of Capital Distributions (Unaudited) 4/2/2015 4/15/2015 $ 0.4921875 $ 0.4921875 $ 0.00 7/2/2015 7/15/2015 0.4921875 0.4921875 0.00 10/2/2015 10/15/2015 0.4921875 0.4921875 0.00 12/30/2015 1/15/2016 0.4921875 0.4921875 0.00 $ 1.9687500 $ 1.9687500 $ 0.00 For the year ended December 31, 2016 , DFT declared and paid a cash dividend on its Series A Preferred Stock, of which the OP paid an equivalent distribution on its preferred units: Record Date Payment Date Cash Dividend Ordinary Taxable Dividend (Unaudited) Nontaxable Return of Capital Distributions (Unaudited) 4/1/2016 4/15/2016 $ 0.4921875 $ 0.4921875 $ 0.00 $ 0.4921875 $ 0.4921875 $ 0.00
Series B Preferred Stock [Member]
Preferred Stock Dividend [Line Items]
Schedule of Preferred Stock Dividend [Table Text Block]	For the year ended December 31, 2015 , DFT declared and paid the following cash dividends on its Series B Preferred Stock, of which the OP paid an equivalent distribution on its preferred units: Record Date Payment Date Cash Dividend Ordinary Taxable Dividend (Unaudited) Nontaxable Return of Capital Distributions (Unaudited) 4/2/2015 4/15/2015 $ 0.4765625 $ 0.4765625 $ 0.00 7/2/2015 7/15/2015 0.4765625 0.4765625 0.00 10/2/2015 10/15/2015 0.4765625 0.4765625 0.00 12/30/2015 1/15/2016 0.4765625 0.4765625 0.00 $ 1.9062500 $ 1.9062500 $ 0.00 For the year ended December 31, 2016 , DFT declared and paid the following cash dividends on its Series B Preferred Stock, of which the OP paid an equivalent distribution on its preferred units: Record Date Payment Date Cash Dividend Ordinary Taxable Dividend (Unaudited) Nontaxable Return of Capital Distributions (Unaudited) 4/1/2016 4/15/2016 $ 0.4765625 $ 0.4765625 $ 0.00 7/1/2016 7/15/2016 0.4765625 0.4765625 0.00 $ 0.9531250 $ 0.9531250 $ 0.00 For the year ended December 31, 2014 , DFT declared and paid the following cash dividends on its Series B Preferred Stock, of which the OP paid an equivalent distribution on its preferred units: Record Date Payment Date Cash Dividend Ordinary Taxable Dividend (Unaudited) Nontaxable Return of Capital Distributions (Unaudited) 4/4/2014 4/15/2014 $ 0.4765625 $ 0.4765625 $ 0.00 7/3/2014 7/15/2014 0.4765625 0.4765625 0.00 10/3/2014 10/15/2014 0.4765625 0.4765625 0.00 12/30/2014 1/15/2015 0.4765625 0.4765625 0.00 $ 1.9062500 $ 1.9062500 $ 0.00
Series C Preferred Stock [Member]
Preferred Stock Dividend [Line Items]
Schedule of Preferred Stock Dividend [Table Text Block]	For the year ended December 31, 2016 , DFT declared the following cash dividends on its Series C Preferred Stock, of which the OP will pay or has paid an equivalent distribution on its preferred units: Record Date Payment Date Cash Dividend Ordinary Taxable Dividend (Unaudited) Nontaxable Return of Capital Distributions (Unaudited) 8/1/2016 8/15/2016 $ 0.4094618 $ 0.4094618 $ 0.00 11/1/2016 11/15/2016 0.4140625 0.4140625 0.00 $ 0.8235243 $ 0.8235243 $ 0.00

11. Stockholders Equity of th37

11. Stockholders Equity of the REIT and Partners Capital of the OP (Tables)	12 Months Ended
	Dec. 31, 2016
Stockholders’ Equity of the REIT and Partners’ Capital of the OP [Abstract]
Schedule Of Common Stock Dividend [Table Text Block]	For the year ended December 31, 2014 , DFT declared and paid the following cash dividends totaling $1.47 per share on its common stock, of which the OP paid equivalent distributions on OP units: Record Date Payment Date Cash Dividend Ordinary Taxable Dividend (Unaudited) Nontaxable Return of Capital Distributions (Unaudited) 04/04/2014 04/15/2014 $ 0.35 $ 0.35 $ — 07/03/2014 07/15/2014 0.35 0.35 — 10/03/2014 10/15/2014 0.35 0.35 — 12/30/2014 01/15/2015 0.42 0.39 — $ 1.47 $ 1.44 $ — For the year ended December 31, 2016 , DFT declared and paid the following cash dividends totaling $1.91 per share on its common stock, of which the OP paid equivalent distributions on OP units: Record Date Payment Date Cash Dividend Ordinary Taxable Dividend (Unaudited) Nontaxable Return of Capital Distributions (Unaudited) 04/01/2016 04/15/2016 $ 0.47 $ 0.26 $ 0.21 07/01/2016 07/15/2016 0.47 0.26 0.21 10/07/2016 10/17/2016 0.47 0.26 0.21 12/30/2016 01/17/2017 0.50 — — $ 1.91 $ 0.78 $ 0.63 For the year ended December 31, 2015 , DFT declared and paid the following cash dividends totaling $1.73 per share on its common stock, of which the OP paid equivalent distributions on OP units: Record Date Payment Date Cash Dividend Ordinary Taxable Dividend (Unaudited) Nontaxable Return of Capital Distributions (Unaudited) 04/02/2015 04/15/2015 $ 0.42 $ 0.42 $ — 07/02/2015 07/15/2015 0.42 0.42 — 10/02/2015 10/15/2015 0.42 0.42 — 12/30/2015 01/16/2016 0.47 0.33 — $ 1.73 $ 1.59 $ —

12. Equity Compensation Plan (T

12. Equity Compensation Plan (Tables)	12 Months Ended
	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Unvested Restricted Stock Units Roll Forward [Table Text Block]	The following table sets forth the number of unvested shares of restricted stock and the weighted average fair value of these shares at the date of grant: Shares of Restricted Stock Weighted Average Fair Value at Date of Grant Unvested balance at December 31, 2013 303,964 $ 22.89 Granted 149,608 $ 25.63 Vested (125,798 ) $ 23.02 Forfeited (3,785 ) $ 23.98 Unvested balance at December 31, 2014 323,989 $ 24.10 Granted 171,475 $ 32.12 Vested (138,585 ) $ 23.87 Forfeited (7,737 ) $ 28.71 Unvested balance at December 31, 2015 349,142 $ 28.02 Granted 175,410 $ 33.96 Vested (167,419 ) $ 25.66 Forfeited (47,958 ) $ 30.41 Unvested balance at December 31, 2016 309,175 $ 32.30
Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]	A summary of our stock option activity for the years ended December 31, 2016 , 2015 and 2014 is presented in the tables below. Number of Options Weighted Average Exercise Price Under option, December 31, 2013 2,099,910 $ 17.13 Granted — $ — Exercised (507,056 ) $ 10.95 Forfeited — $ — Under option, December 31, 2014 1,592,854 $ 19.09 Granted — $ — Exercised (362,642 ) $ 21.87 Forfeited — $ — Under option, December 31, 2015 1,230,212 $ 18.28 Granted — $ — Exercised (478,733 ) $ 22.12 Forfeited — $ — Under option, December 31, 2016 751,479 $ 15.83 Shares Subject to Option Total Unearned Compensation Weighted Average Vesting Period Weighted Average Remaining Contractual Term As of December 31, 2014 1,592,854 $ 0.7 million 0.5 years 6.2 years As of December 31, 2015 1,230,212 $ 0.1 million 0.2 years 4.9 years As of December 31, 2016 751,479 $ — 0.0 years 3.6 years
Schedule of Stock Options Roll Forward [Table Text Block]	The following table sets forth the number of unvested options as of December 31, 2016 , 2015 and 2014 and the weighted average fair value of these options at the grant date. Number of Options Weighted Average Fair Value at Date of Grant Unvested balance at December 31, 2013 684,111 $ 5.73 Granted — $ — Vested (381,787 ) $ 6.28 Forfeited — $ — Unvested balance at December 31, 2014 302,324 $ 5.05 Granted — $ — Vested (263,553 ) $ 5.10 Forfeited — $ — Unvested balance at December 31, 2015 38,771 $ 4.75 Granted — $ — Vested (38,771 ) $ 4.75 Forfeited — $ — Unvested balance at December 31, 2016 — $ —
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable [Table Text Block]	The following tables set forth the number of exercisable options as of December 31, 2016 , 2015 and 2014 and the weighted average fair value and exercise price of these options at the grant date. Number of Options Weighted Average Fair Value at Date of Grant Options Exercisable at December 31, 2013 1,415,799 $ 4.81 Vested 381,787 $ 6.28 Exercised (507,056 ) $ 3.54 Options Exercisable at December 31, 2014 1,290,530 $ 5.74 Vested 263,553 $ 5.10 Exercised (362,642 ) $ 6.34 Options Exercisable at December 31, 2015 1,191,441 $ 5.41 Vested 38,771 $ 4.75 Exercised (478,733 ) $ 6.46 Options Exercisable at December 31, 2016 751,479 $ 4.71 Exercisable Options Intrinsic Value Weighted Average Exercise Price Weighted Average Remaining Contractual Term As of December 31, 2014 1,290,530 $ 19.3 million $ 18.27 5.8 years As of December 31, 2015 1,191,441 $ 16.3 million $ 18.14 4.9 years As of December 31, 2016 751,479 $ 21.1 million $ 15.83 3.6 years
Schedule of Share-based Payment Award, Performance Units, Valuation Assumptions [Table Text Block]	The following table summarizes the assumptions used to value, and the resulting fair and maximum values of, the performance units granted during the years ended December 31, 2016 , 2015 and 2014 . 2016 2015 2014 Number of performance units granted 112,951 48,674 110,441 Expected volatility 24% 24% 30% Expected annual dividend 6% 5% 5% Risk-free rate 1.32% 1.06% 0.74% Performance unit fair value at date of grant $38.08 $38.34 $33.50 Total grant fair value at date of grant $4.3 million $1.9 million $3.7 million Maximum value of grant on vesting date based on closing price of DFT's stock at the date of grant $10.7 million $4.7 million $8.5 million
Share-based Compensation, Performance Shares Award Outstanding Activity [Table Text Block]	The following table sets forth the number of performance units outstanding and the fair value per unit at the date of grant as of December 31, 2016 . Grant Date Grant Date Fair Value per Unit Units Granted Units Vested Units Accelerated (1) Units Forfeited Units Outstanding Payout Total Shares Issued 2/23/2012 (2) $28.26 61,033 (49,936 ) — (11,097 ) — —% — 2/21/2013 (3) $25.59 60,468 (10,995 ) (38,479 ) (10,994 ) — 300% 148,422 2/21/2014 (4) $33.50 110,441 — (70,538 ) (1,785 ) 38,118 (4) 207,365 3/16/2015 $38.34 48,674 — (651 ) (2,440 ) 45,583 100% 651 1/5/2016 $38.08 112,951 — — — 112,951 393,567 (60,931 ) (109,668 ) (26,316 ) 196,652 356,438 (1) Represents accelerated vesting of performance units due to departure of certain executives. In connection with the departure of our former CEO in February 2015, 320,676 common shares were issued pursuant to the accelerated vesting of certain of his unvested performance units. $1.9 million was expensed during the first quarter of 2015 related to the accelerated vesting of these performance units. (2) For the performance units granted in 2012, based on DFT’s total stockholder return compared to the MSCI US REIT index return for the period from January 1, 2012 to January 1, 2015, no common shares were issued upon vesting on March 1, 2015. (3) For the performance units granted in 2013, 115,437 common shares were issued due to the accelerated vesting of certain unvested performance units, which represented a 300% payout. Based on DFT’s total stockholder return compared to the MSCI US REIT index return for the period from January 1, 2013 to January 1, 2016, 32,985 common shares were issued upon the vesting of these performance units on March 1, 2016, which represented a 300% payout. (4) For the performance units granted in 2014, 205,240 common shares were issued, which represented a 300% payout, and 2,125 common shares were issued, which represented a 100% payout, due to the accelerated vesting of certain unvested performance units. Based on DFT’s total stockholder return compared to the MSCI US REIT index return for half of the grant and an index of five comparable publicly traded data center companies for the other half of the grant for the period from January 1, 2014 to January 1, 2017, 57,177 common shares will be issued upon their vesting on March 1, 2017, which represents an aggregate payout of 150% .

13. Earnings Per Share of the39

13. Earnings Per Share of the REIT (Tables)	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	The following table sets forth the reconciliation of basic and diluted average shares outstanding used in the computation of earnings per share of common stock (in thousands except for share and per share amounts): Twelve months ended December 31, 2016 2015 2014 Basic and Diluted Shares Outstanding Weighted average common shares – basic 73,003,164 65,184,013 65,486,108 Effect of dilutive securities 835,872 — 600,271 Weighted average common shares – diluted 73,839,036 65,184,013 66,086,379 Calculation of Earnings per Share – Basic Net income (loss) attributable to common shares $ 123,965 $ (25,338 ) $ 78,662 Net income allocated to unvested restricted shares (628 ) (599 ) (484 ) Net income (loss) attributable to common shares, adjusted 123,337 (25,937 ) 78,178 Weighted average common shares – basic 73,003,164 65,184,013 65,486,108 Earnings (loss) per common share – basic $ 1.69 $ (0.40 ) $ 1.19 Calculation of Earnings per Share – Diluted Net income (loss) attributable to common shares, adjusted $ 123,337 $ (25,937 ) $ 78,178 Weighted average common shares – diluted 73,839,036 65,184,013 66,086,379 Earnings (loss) per common share – diluted $ 1.67 $ (0.40 ) $ 1.18
Schedule of exclusions from diluted earnings per share/unit [Table Text Block]	The following table sets forth the amount of stock options and performance units that have been excluded from the calculation of diluted earnings per share (in millions): Twelve months ended December 31, 2016 2015 2014 Stock Options — 0.6 — Performance Units 0.1 0.1 0.1

14. Earnings Per Unit of the 40

14. Earnings Per Unit of the Operating Partnership (Tables)	12 Months Ended
	Dec. 31, 2016
Earnings per unit of the Operating Partnership [Line Items]
Schedule of basic and diluted units outstanding [Table Text Block]	The following table sets forth the reconciliation of basic and diluted average shares outstanding used in the computation of earnings per share of common stock (in thousands except for share and per share amounts): Twelve months ended December 31, 2016 2015 2014 Basic and Diluted Shares Outstanding Weighted average common shares – basic 73,003,164 65,184,013 65,486,108 Effect of dilutive securities 835,872 — 600,271 Weighted average common shares – diluted 73,839,036 65,184,013 66,086,379 Calculation of Earnings per Share – Basic Net income (loss) attributable to common shares $ 123,965 $ (25,338 ) $ 78,662 Net income allocated to unvested restricted shares (628 ) (599 ) (484 ) Net income (loss) attributable to common shares, adjusted 123,337 (25,937 ) 78,178 Weighted average common shares – basic 73,003,164 65,184,013 65,486,108 Earnings (loss) per common share – basic $ 1.69 $ (0.40 ) $ 1.19 Calculation of Earnings per Share – Diluted Net income (loss) attributable to common shares, adjusted $ 123,337 $ (25,937 ) $ 78,178 Weighted average common shares – diluted 73,839,036 65,184,013 66,086,379 Earnings (loss) per common share – diluted $ 1.67 $ (0.40 ) $ 1.18
Schedule of exclusions from diluted earnings per share/unit [Table Text Block]	The following table sets forth the amount of stock options and performance units that have been excluded from the calculation of diluted earnings per share (in millions): Twelve months ended December 31, 2016 2015 2014 Stock Options — 0.6 — Performance Units 0.1 0.1 0.1
Subsidiaries [Member]
Earnings per unit of the Operating Partnership [Line Items]
Schedule of basic and diluted units outstanding [Table Text Block]	The following table sets forth the reconciliation of basic and diluted average units outstanding used in the computation of earnings per unit: Twelve months ended December 31, 2016 2015 2014 Basic and Diluted Units Outstanding Weighted average common units – basic (includes redeemable partnership units and units of general and limited partners) 87,284,564 80,599,199 81,053,127 Effect of dilutive securities 835,872 — 600,271 Weighted average common units – diluted 88,120,436 80,599,199 81,653,398 Calculation of Earnings per Unit – Basic Net income (loss) attributable to common units 148,213 (31,331 ) 97,366 Net income allocated to unvested restricted units (628 ) (599 ) (484 ) Net income (loss) attributable to common units, adjusted 147,585 (31,930 ) 96,882 Weighted average common units – basic 87,284,564 80,599,199 81,053,127 Earnings (loss) per common unit – basic $ 1.69 $ (0.40 ) $ 1.19 Calculation of Earnings per Unit – Diluted Net income (loss) attributable to common units, adjusted 147,585 (31,930 ) 96,882 Weighted average common units – diluted 88,120,436 80,599,199 81,653,398 Earnings per common unit – diluted $ 1.67 $ (0.40 ) $ 1.18
Schedule of exclusions from diluted earnings per share/unit [Table Text Block]	The following table sets forth the amount of stock options and performance units that have been excluded from the calculation of diluted earnings per unit (in millions): Twelve months ended December 31, 2016 2015 2014 Stock Options — 0.6 — Performance Units 0.1 0.1 0.1

17. Quarterly Financial Infor41

17. Quarterly Financial Information (Tables)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information [Table Text Block]	The table below reflects the selected quarterly information for the years ended December 31, 2016 and 2015 (in thousands except share data): Three months ended December 31, 2016 September 30, 2016 June 30, 2016 March 31, 2016 Total revenue $ 141,688 $ 134,326 $ 128,538 $ 124,149 Net income (1) 43,227 40,966 60,557 36,697 Net income attributable to common shares (1) 33,734 28,524 37,299 24,408 Net income attributable to common shares per common share-basic (1) 0.45 0.38 0.50 0.36 Net income attributable to common shares per common share-diluted (1) (2) 0.44 0.37 0.49 0.36 Three months ended December 31, 2015 September 30, 2015 June 30, 2015 March 31, 2015 Total revenue $ 115,923 $ 115,337 $ 113,826 $ 107,314 Net (loss) income (3) (91,953 ) 30,393 31,141 26,333 Net (loss) income attributable to common shares (3) (79,871 ) 19,062 19,668 15,803 Net (loss) income attributable to common shares per common share-basic (3) (1.23 ) 0.29 0.30 0.24 Net (loss) income attributable to common shares per common share-diluted (3) (1.23 ) 0.29 0.30 0.24 (1) Net income for the quarter ended June 30, 2016 includes a gain on sale of real estate of $22.8 million . (2) Amounts do not equal full year results due to rounding. (3) Net loss for the quarter ended December 31, 2015 includes an impairment on investment in real estate of $122.5 million .

18. Supplemental Consolidatin42

18. Supplemental Consolidating Financial Data for Subsidiary Guarantors of the Unsecured Notes (Tables)	12 Months Ended
	Dec. 31, 2016
Supplemental Consolidating Financial Data for Subsidiary Guarantors of the Unsecured Notes [Abstract]
Schedule of Supplemental Consolidating Balance Sheets [Table Text Block]	DUPONT FABROS TECHNOLOGY, L.P. SUPPLEMENTAL CONSOLIDATING BALANCE SHEETS (in thousands except share data) December 31, 2016 Operating Partnership Subsidiary Guarantors Subsidiary Non-Guarantors Eliminations Consolidated Total ASSETS Income producing property: Land $ — $ 80,673 $ 25,217 $ — $ 105,890 Buildings and improvements — 2,332,771 685,590 — 3,018,361 — 2,413,444 710,807 — 3,124,251 Less: accumulated depreciation — (605,488 ) (56,695 ) — (662,183 ) Net income producing property — 1,807,956 654,112 — 2,462,068 Construction in progress and land held for development — 88,836 242,147 — 330,983 Net real estate — 1,896,792 896,259 — 2,793,051 Cash and cash equivalents 31,781 — 2,628 — 34,409 Rents and other receivables 1,390 4,743 5,400 — 11,533 Deferred rent — 109,142 13,916 — 123,058 Lease contracts above market value, net — 5,138 — — 5,138 Deferred costs, net 6,066 11,632 8,078 — 25,776 Investment in affiliates 2,713,096 — — (2,713,096 ) — Prepaid expenses and other assets 3,463 27,341 10,480 — 41,284 Total assets $ 2,755,796 $ 2,054,788 $ 936,761 $ (2,713,096 ) $ 3,034,249 LIABILITIES AND PARTNERS’ CAPITAL Liabilities: Line of credit $ 50,926 $ — $ — $ — $ 50,926 Mortgage notes payable, net of deferred financing costs — — 110,733 — 110,733 Unsecured term loan, net of deferred financing costs 249,036 — — — 249,036 Unsecured notes payable, net of discount and deferred financing costs 837,323 — — — 837,323 Accounts payable and accrued liabilities 6,477 22,319 8,113 — 36,909 Construction costs payable — 10,159 46,269 — 56,428 Accrued interest payable 11,578 — 14 — 11,592 Distribution payable 46,352 — — — 46,352 Lease contracts below market value, net — 2,830 — — 2,830 Prepaid rents and other liabilities 216 58,599 19,417 — 78,232 Total liabilities 1,201,908 93,907 184,546 — 1,480,361 Redeemable partnership units 591,101 — — — 591,101 Commitments and contingencies — — — — — Limited Partners’ Capital: Series C cumulative redeemable perpetual preferred units, 8,050,000 issued and outstanding at December 31, 2016 201,250 — — — 201,250 Common units, 75,252,390 issued and outstanding at December 31, 2016 754,892 1,960,881 752,215 (2,713,096 ) 754,892 General partner’s capital, 662,373 common units issued and outstanding at December 31, 2016 6,645 — — — 6,645 Total partners’ capital 962,787 1,960,881 752,215 (2,713,096 ) 962,787 Total liabilities & partners’ capital $ 2,755,796 $ 2,054,788 $ 936,761 $ (2,713,096 ) $ 3,034,249 DUPONT FABROS TECHNOLOGY, L.P. SUPPLEMENTAL CONSOLIDATING BALANCE SHEETS (in thousands except share data) December 31, 2015 Operating Partnership Subsidiary Guarantors Subsidiary Non-Guarantors Eliminations Consolidated Total ASSETS Income producing property: Land $ — $ 84,258 $ 9,945 $ — $ 94,203 Buildings and improvements — 2,399,016 337,920 — 2,736,936 — 2,483,274 347,865 — 2,831,139 Less: accumulated depreciation — (522,096 ) (38,741 ) — (560,837 ) Net income producing property — 1,961,178 309,124 — 2,270,302 Construction in progress and land held for development — 25,545 275,394 — 300,939 Net real estate — 1,986,723 584,518 — 2,571,241 Cash and cash equivalents 21,697 — 5,318 — 27,015 Rents and other receivables 1,391 7,563 634 — 9,588 Deferred rent — 122,830 6,111 — 128,941 Lease contracts above market value, net — 6,029 — — 6,029 Deferred costs, net 3,236 14,250 6,288 — 23,774 Investment in affiliates 2,546,465 — — (2,546,465 ) — Prepaid expenses and other assets 3,025 39,642 2,022 — 44,689 Total assets $ 2,575,814 $ 2,177,037 $ 604,891 $ (2,546,465 ) $ 2,811,277 LIABILITIES AND PARTNERS’ CAPITAL Liabilities: Line of credit $ — $ — $ — $ — $ — Mortgage notes payable, net of deferred financing costs — — 114,075 — 114,075 Unsecured term loan, net of deferred financing costs 249,172 — — — 249,172 Unsecured notes payable, net of discount and deferred financing costs 834,963 — — — 834,963 Accounts payable and accrued liabilities 4,516 23,615 4,170 — 32,301 Construction costs payable 43 293 21,707 — 22,043 Accrued interest payable 11,815 — 6 — 11,821 Distribution payable 43,906 — — — 43,906 Lease contracts below market value, net — 4,132 — — 4,132 Prepaid rents and other liabilities 12 62,630 4,835 — 67,477 Total liabilities 1,144,427 90,670 144,793 — 1,379,890 Redeemable partnership units 479,189 — — — 479,189 Commitments and contingencies — — — — — Limited Partners’ Capital: Series A cumulative redeemable perpetual preferred units, 7,400,000 issued and outstanding at December 31, 2015 185,000 — — — 185,000 Series B cumulative redeemable perpetual preferred units, 6,650,000 issued and outstanding at December 31, 2015 166,250 — — — 166,250 Common units, 65,443,277 issued and outstanding at December 31, 2015 594,927 2,086,367 460,098 (2,546,465 ) 594,927 General partner’s capital, 662,373 common units issued and outstanding at December 31, 2015 6,021 — — — 6,021 Total partners’ capital 952,198 2,086,367 460,098 (2,546,465 ) 952,198 Total liabilities & partners’ capital $ 2,575,814 $ 2,177,037 $ 604,891 $ (2,546,465 ) $ 2,811,277
Schedule of Supplemental Consolidating Statements of Operations [Table Text Block]	Year ended December 31, 2016 Operating Partnership Subsidiary Guarantors Subsidiary Non-Guarantors Eliminations Consolidated Total Revenues: Base rent $ 18,164 $ 270,357 $ 74,727 $ (18,226 ) $ 345,022 Recoveries from tenants — 142,863 26,805 — 169,668 Other revenues — 1,668 12,388 (45 ) 14,011 Total revenues 18,164 414,888 113,920 (18,271 ) 528,701 Expenses: Property operating costs — 144,935 27,338 (18,209 ) 154,064 Real estate taxes and insurance — 16,916 3,264 — 20,180 Depreciation and amortization 100 88,321 19,360 — 107,781 General and administrative 22,009 52 982 — 23,043 Other expenses 1,564 45 10,234 (62 ) 11,781 Total expenses 23,673 250,269 61,178 (18,271 ) 316,849 Operating (loss) income (5,509 ) 164,619 52,742 — 211,852 Interest: Expense incurred (56,318 ) 1,270 6,754 — (48,294 ) Amortization of deferred financing costs (3,907 ) 79 116 — (3,712 ) Gain on sale of real estate 21,643 — 1,190 — 22,833 Loss on early extinguishment of debt (1,232 ) — — — (1,232 ) Equity in earnings 226,770 — — (226,770 ) — Net income (loss) 181,447 165,968 60,802 (226,770 ) 181,447 Preferred unit distributions (20,739 ) — — — (20,739 ) Issuance costs associated with redeemed preferred units (12,495 ) — — — (12,495 ) Net income (loss) attributable to common units $ 148,213 $ 165,968 $ 60,802 $ (226,770 ) $ 148,213 Year ended December 31, 2015 Operating Partnership Subsidiary Guarantors Subsidiary Non-Guarantors Eliminations Consolidated Total Revenues: Base rent $ 18,061 $ 268,433 $ 30,302 $ (18,211 ) $ 298,585 Recoveries from tenants — 127,877 11,660 — 139,537 Other revenues — 1,787 12,621 (130 ) 14,278 Total revenues 18,061 398,097 54,583 (18,341 ) 452,400 Expenses: Property operating costs — 131,644 16,598 (18,191 ) 130,051 Real estate taxes and insurance — 19,942 1,393 — 21,335 Depreciation and amortization 43 94,371 9,630 — 104,044 General and administrative 17,574 57 433 — 18,064 Impairment on investment in real estate — 119,267 3,205 — 122,472 Other expenses 6,151 133 10,725 (150 ) 16,859 Total expenses 23,768 365,414 41,984 (18,341 ) 412,825 Operating (loss) income (5,707 ) 32,683 12,599 — 39,575 Interest: Expense incurred (50,021 ) 1,327 8,184 — (40,510 ) Amortization of deferred financing costs (3,454 ) 107 196 — (3,151 ) Equity in earnings 55,096 — — (55,096 ) — Net (loss) income (4,086 ) 34,117 20,979 (55,096 ) (4,086 ) Preferred unit distributions (27,245 ) — — — (27,245 ) Net (loss) income attributable to common units $ (31,331 ) $ 34,117 $ 20,979 $ (55,096 ) $ (31,331 ) Year ended December 31, 2014 Operating Partnership Subsidiary Guarantors Subsidiary Non-Guarantors Eliminations Consolidated Total Revenues: Base rent $ 17,499 $ 267,454 $ 18,413 $ (17,650 ) $ 285,716 Recoveries from tenants — 115,185 9,668 — 124,853 Other revenues — 1,657 5,489 (123 ) 7,023 Total revenues 17,499 384,296 33,570 (17,773 ) 417,592 Expenses: Property operating costs — 123,140 11,822 (17,623 ) 117,339 Real estate taxes and insurance — 13,323 872 — 14,195 Depreciation and amortization 63 90,770 5,947 — 96,780 General and administrative 16,159 82 940 — 17,181 Other expenses 3,508 1,526 4,338 (150 ) 9,222 Total expenses 19,730 228,841 23,919 (17,773 ) 254,717 Operating (loss) income (2,231 ) 155,455 9,651 — 162,875 Interest: Expense incurred (41,107 ) 4,323 3,201 — (33,583 ) Amortization of deferred financing costs (3,173 ) 273 (80 ) — (2,980 ) Loss on early extinguishment of debt (1,701 ) — — — (1,701 ) Equity in earnings 172,823 — — (172,823 ) — Net income 124,611 160,051 12,772 (172,823 ) 124,611 Preferred unit distributions (27,245 ) — — — (27,245 ) Net income attributable to common units $ 97,366 $ 160,051 $ 12,772 $ (172,823 ) $ 97,366
Schedule of Supplemental Consolidating Statements Of Cash Flows [Table Text Block]	DUPONT FABROS TECHNOLOGY, L.P. SUPPLEMENTAL CONSOLIDATING STATEMENTS OF CASH FLOWS (in thousands) Year ended December 31, 2016 Operating Partnership Subsidiary Guarantors Subsidiary Non-Guarantors Eliminations Consolidated Total Cash flow from operating activities Net cash (used in) provided by operating activities $ (60,010 ) $ 265,244 $ 84,728 $ — $ 289,962 Return on investment in subsidiaries 349,972 — — (349,972 ) — Net cash provided by operating activities 289,962 265,244 84,728 (349,972 ) 289,962 Cash flow from investing activities Proceeds from the sale of real estate — 120,086 3,459 — 123,545 Investments in real estate – development — (62,343 ) (232,421 ) — (294,764 ) Acquisition of real estate — — (53,105 ) — (53,105 ) Acquisition of real estate – related party — — (20,168 ) — (20,168 ) Investments in subsidiaries (384,605 ) — — 384,605 — Return of investment in subsidiaries 123,545 — — (123,545 ) — Interest capitalized for real estate under development (2 ) (1,269 ) (9,109 ) — (10,380 ) Improvements to real estate — (4,739 ) (104 ) — (4,843 ) Additions to non real estate property (1,008 ) (220 ) (42 ) — (1,270 ) Net cash (used in) provided by investing activities (262,070 ) 51,515 (311,490 ) 261,060 (260,985 ) Cash flow from financing activities Line of credit: Proceeds 135,899 — — — 135,899 Repayments (85,000 ) — — — (85,000 ) Mortgage notes payable: Repayments — — (3,750 ) — (3,750 ) Payments of financing costs (5,841 ) — (25 ) — (5,866 ) Issuance of common units, net of offering costs 275,470 — — — 275,470 Issuance of preferred units, net of offering costs 194,252 — — — 194,252 Redemption of preferred units (351,250 ) — — — (351,250 ) Equity compensation proceeds 7,623 — — — 7,623 Parent financing — 68,571 316,034 (384,605 ) — Distribution to parent — (385,330 ) (88,187 ) 473,517 — Distributions (188,961 ) — — — (188,961 ) Net cash (used in) provided by financing activities (17,808 ) (316,759 ) 224,072 88,912 (21,583 ) Net increase (decrease) in cash and cash equivalents 10,084 — (2,690 ) — 7,394 Cash and cash equivalents, beginning of period 21,697 — 5,318 — 27,015 Cash and cash equivalents, ending of period $ 31,781 $ — $ 2,628 $ — $ 34,409 DUPONT FABROS TECHNOLOGY, L.P. SUPPLEMENTAL CONSOLIDATING STATEMENTS OF CASH FLOWS (in thousands) Year ended December 31, 2015 Operating Partnership Subsidiary Guarantors Subsidiary Non-Guarantors Eliminations Consolidated Total Cash flow from operating activities Net cash (used in) provided by operating activities $ (55,999 ) $ 278,557 $ 32,466 $ — $ 255,024 Cash flow from investing activities Investments in real estate – development (415 ) (8,996 ) (207,928 ) — (217,339 ) Acquisition of real estate — — (8,600 ) — (8,600 ) Investments in subsidiaries 68,074 (264,211 ) 196,137 — — Interest capitalized for real estate under development (27 ) (1,327 ) (10,210 ) — (11,564 ) Improvements to real estate — (3,401 ) (58 ) — (3,459 ) Additions to non real estate property (93 ) (622 ) (38 ) — (753 ) Net cash provided by (used in) investing activities 67,539 (278,557 ) (30,697 ) — (241,715 ) Cash flow from financing activities Line of credit: Proceeds 120,000 — — — 120,000 Repayments (180,000 ) — — — (180,000 ) Unsecured notes payable: Proceeds 248,012 — — — 248,012 Payments of financing costs (4,715 ) — (25 ) — (4,740 ) Equity compensation proceeds 249 — — — 249 OP unit repurchases (31,912 ) — — — (31,912 ) Distributions (163,283 ) — — — (163,283 ) Net cash (used in) financing activities (11,649 ) — (25 ) — (11,674 ) Net (decrease) increase in cash and cash equivalents (109 ) — 1,744 — 1,635 Cash and cash equivalents, beginning of period 21,806 — 3,574 — 25,380 Cash and cash equivalents, ending of period $ 21,697 $ — $ 5,318 $ — $ 27,015 Year ended December 31, 2014 Operating Partnership Subsidiary Guarantors Subsidiary Non-Guarantors Eliminations Consolidated Total Cash flow from operating activities Net cash (used in) provided by operating activities $ (40,234 ) $ 264,409 $ 20,339 $ — $ 244,514 Cash flow from investing activities Investments in real estate – development (404 ) (111,791 ) (153,179 ) — (265,374 ) Investments in subsidiaries 5,654 (146,188 ) 140,534 — — Interest capitalized for real estate under development (10 ) (4,323 ) (5,311 ) — (9,644 ) Improvements to real estate — (1,850 ) (66 ) — (1,916 ) Additions to non real estate property (20 ) (257 ) (39 ) — (316 ) Net cash provided by (used) in investing activities 5,220 (264,409 ) (18,061 ) — (277,250 ) Cash flow from financing activities Line of credit: Proceeds 60,000 — — — 60,000 Unsecured term loan: Proceeds 96,000 — — — 96,000 Payments of financing costs (3,514 ) — (315 ) — (3,829 ) Equity compensation proceeds 4,363 — — — 4,363 Distributions (132,932 ) — — — (132,932 ) Net cash provided by (used in) financing activities 23,917 — (315 ) — 23,602 Net (decrease) increase in cash and cash equivalents (11,097 ) — 1,963 — (9,134 ) Cash and cash equivalents, beginning of period 32,903 — 1,611 — 34,514 Cash and cash equivalents, ending of period $ 21,806 $ — $ 3,574 $ — $ 25,380

Schedule II - Consolidated Al43

Schedule II - Consolidated Allowance for Doubtful Accounts (Tables)	12 Months Ended
	Dec. 31, 2016
Valuation and Qualifying Accounts Disclosure [Line Items]
Schedule of Valuation and Qualifying Accounts Disclosure [Text Block]	Balance at Beginning of Period Charged to Operations (1) Other Accounts (2) Deductions Balance at End of Period Allowance for doubtful accounts: Twelve months ended December 31, 2016 $ 5,241 $ (108 ) $ 18,486 $ — $ 23,619 Twelve months ended December 31, 2015 8,520 372 — (3,651 ) 5,241 Twelve months ended December 31, 2014 3,700 4,829 — (9 ) 8,520 (1) Amounts charged to operations are net of recoveries. (2) Relates to an allowance on a $25.0 million note receivable which resulted from the settlement of our claim in a former customer's bankruptcy proceedings in the fourth quarter of 2016 (see Footnote 2 to consolidated financial statements).
Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Schedule of Valuation and Qualifying Accounts Disclosure [Text Block]	Balance at Beginning of Period Charged to Operations (1) Other Accounts (2) Deductions Balance at End of Period Allowance for doubtful accounts: Twelve months ended December 31, 2016 $ 5,241 $ (108 ) $ 18,486 $ — $ 23,619 Twelve months ended December 31, 2015 8,520 372 — (3,651 ) 5,241 Twelve months ended December 31, 2014 3,700 4,829 — (9 ) 8,520 (1) Amounts charged to operations are net of recoveries. (2) Relates to an allowance on a $25.0 million note receivable which resulted from the settlement of our claim in a former customer's bankruptcy proceedings in the fourth quarter of 2016 (see Footnote 2 to consolidated financial statements).

Schedule III - Consolidated R44

Schedule III - Consolidated Real Estate and Accumulated Depreciation (Tables)	12 Months Ended
	Dec. 31, 2016
Real Estate and Accumulated Depreciation [Line Items]
Schedule Of Real Estate And Accumulated Depreciation [Table Text Block]	Encum-brances Initial Cost at Costs Capitalized Gross Carry Amount at Accumulated Year Year Life on which depreciation in latest income statements is computed Land Building and improvements / Construction in progress Buildings & Land Building and improvements / Construction in progress Total Operating Properties ACC2 (1) $ — $ 2,500 $ 157,100 $ (620 ) $ 2,500 $ 156,480 $ 158,980 $ (57,184 ) 2005 2001 28.5 ACC3 (2) 111,250 1,071 92,631 3,449 $ 1,071 96,080 97,151 (36,136 ) 2006 2001 29.8 ACC4 (1) — 6,600 535,526 3,343 $ 6,600 538,869 545,469 (176,477 ) 2007 2006 30.8 ACC5 (1) — 6,443 292,369 6,647 $ 6,443 299,016 305,459 (71,347 ) 2009-2010 2007 29.7 ACC6 (1) — 5,518 215,235 1,594 $ 5,518 216,829 222,347 (35,197 ) 2011-2013 2007 30.7 ACC7 — 9,753 328,520 4,450 $ 9,753 332,970 342,723 (13,320 ) 2014-2016 2011 32.5 CH1 (1) — 23,611 357,194 1,977 $ 23,611 359,171 382,782 (82,947 ) 2008-2012 2007 30.5 CH2 — 14,392 255,593 946 $ 14,392 256,539 270,931 (7,239 ) 2015-2016 2013 30.7 SC1 Phases I-II (1) — 20,202 429,572 3,527 $ 20,202 433,099 453,301 (53,697 ) 2011-2015 2007 31.7 VA3 (1) — 9,000 172,881 6,813 $ 9,000 179,694 188,694 (72,725 ) 2003 2003 30.5 VA4 (1) — 6,800 140,575 9,039 $ 6,800 149,614 156,414 (55,914 ) 2005 2005 31.1 Subtotal 111,250 105,890 2,977,196 41,165 105,890 3,018,361 3,124,251 (662,183 ) Development Properties ACC8 — 3,786 466 — 3,786 466 4,252 — 2007 ACC9 — 8,469 138,561 — 8,469 138,561 147,030 — 2016 ACC10 — 7,343 1,872 — 7,343 1,872 9,215 — 2016 ACC11 — 4,773 6 — 4,773 6 4,779 — 2016 CH3 — 8,578 8,740 — 8,578 8,740 17,318 — 2015 OR1 — 5,775 1,328 — 5,775 1,328 7,103 — 2016 OR2 — 5,775 301 — 5,775 301 6,076 — 2016 SC1 Phase III (1) — 5,232 83,604 — 5,232 83,604 88,836 — 2007 TOR1 — 42,128 4,246 — 42,128 4,246 46,374 — 2016 Subtotal — 91,859 239,124 — 91,859 239,124 330,983 — Grand Total (3) $ 111,250 $ 197,749 $ 3,216,320 $ 41,165 $ 197,749 $ 3,257,485 $ 3,455,234 $ (662,183 ) (1) The subsidiaries that own these data centers and development properties are guarantors of the Unsecured Notes due 2021 and 2023, the Unsecured Credit Facility and the Unsecured Term Loan. (2) The subsidiary that owns this data center is encumbered by our ACC3 Term Loan. (3) The aggregate gross cost of our properties for federal income tax purposes was $2.78 billion (unaudited) as of December 31, 2016 .
Schedule of Reconciliation Of Real Estate Assets and Accumulated Depreciation [Table Text Block]	2016 2015 2014 Real estate assets Balance, beginning of period $ 3,132,078 $ 3,066,297 $ 2,799,010 Additions - property acquisitions 73,273 8,600 — Additions - improvements 344,960 221,588 267,357 Deductions - write-offs, sales, impairments (95,077 ) (164,407 ) (70 ) Balance, end of period $ 3,455,234 $ 3,132,078 $ 3,066,297 Accumulated depreciation Balance, beginning of period $ 560,837 $ 504,869 $ 413,394 Additions - depreciation 102,614 97,988 91,545 Deductions - write-offs, sales (1,268 ) (42,020 ) (70 ) Balance, end of period $ 662,183 $ 560,837 $ 504,869

1. Description of Business (Det

1. Description of Business (Details)	12 Months Ended
	Dec. 31, 2016
Subsidiary or Equity Method Investee [Line Items]
Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Ownership Interest	84.90%
Limited Liability Company (LLC) or Limited Partnership (LP), Managing Member or General Partner, Ownership Interest	0.90%

2. Significant Accounting Pol46

2. Significant Accounting Policies Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Significant Accounting Policies [Line Items]
Cash at Bank Held by Parent Company not Part of Operating Partnership	$ 4,200
Capitalized Interest and Deferred Financing Cost Amortization	11,000	$ 12,300	$ 10,200
Capitalized Internal Leasing And Development Costs	8,000	7,500	4,500
Depreciation	103,500	98,800	92,300
Asset Impairment Charges	0	122,500	0
Gain (Loss) on Disposition of Property Plant Equipment	22,833	0	0
Loss on early extinguishment of debt	(1,232)	0	(1,701)
Write off of Deferred Debt Issuance Cost	1,232	0	1,701
Write off of Unamortized Leasing Costs		700
Amortization of Deferred Leasing Fees	4,200	4,900	4,100
Fuel Inventory	4,200	4,500
Write Off of Unreserved Straight-Line Rents Receivable		400
Write off of Unamortized Lease Inducements		100
Write off of Unamortized Lease Intangibles		1,000
Notes Receivable, Gross	25,000	6,500
Account receivable reserve	23,600	5,100
Notes Receivable, Net	1,400	1,400
DeferredRentReceivablesAllowance	0	100
Income Tax Expense (Benefit)	100	0	100
Deferred Income Tax Expense (Benefit)		(200)
Deferred Tax Assets, Gross	200	4,600
Deferred Tax Liabilities, Gross	0	2,300
Deferred Tax Assets, Net	200	2,300
Operating Loss Carryforwards	200
Allocated Share-based Compensation Expense	6,600	5,300	6,200
Employee Service Share-based Compensation, Allocation of Recognized Period Costs, Capitalized Amount	900	800	700
Foreign Currency Transaction Gain (Loss), before Tax	100
Retained Earnings (Accumulated Deficit)	$ 0	$ (79,945)
Building and Building Improvements [Member]
Significant Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life	40 years
Minimum [Member] | Building and Building Improvements [Member]
Significant Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life	10 years
Minimum [Member] | Personal Property [Member]
Significant Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Maximum [Member] | Building and Building Improvements [Member]
Significant Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life	40 years
Maximum [Member] | Personal Property [Member]
Significant Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life	7 years
Revolving Credit Facility [Member]
Significant Accounting Policies [Line Items]
Loss on early extinguishment of debt	$ 1,232
Write off of Deferred Debt Issuance Cost	$ 500		300
Unsecured Term Loan [Member]
Significant Accounting Policies [Line Items]
Loss on early extinguishment of debt			1,400
Write off of Deferred Debt Issuance Cost			$ 700

2. Significant Accounting Pol47

2. Significant Accounting Policies Schedule of Deferred Financing Costs (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Assets [Member]
Significant Accounting Policies [Line Items]
Financing costs	$ 12,352	$ 8,198
Accumulated amortization	(6,376)	(4,969)
Financing costs, net	5,976	3,229
Liability [Member]
Significant Accounting Policies [Line Items]
Financing costs	20,423	20,531
Accumulated amortization	(7,935)	(5,618)
Financing costs, net	$ 12,488	$ 14,913

2. Significant Accounting Pol48

2. Significant Accounting Policies Schedule of Leasing Costs Incurred (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Schedule of Leasing Costs Incurred [Line Items]
Payments for Leasing Costs	$ 3,900	$ 4,200	$ 4,200
Costs incurred for new leases
Schedule of Leasing Costs Incurred [Line Items]
Payments for Leasing Costs	3,690	2,096	2,000
Costs incurred for renewals
Schedule of Leasing Costs Incurred [Line Items]
Payments for Leasing Costs	202	1,188	200
Costs incurred for re-leases
Schedule of Leasing Costs Incurred [Line Items]
Payments for Leasing Costs	$ 0	$ 900	$ 2,000

2. Significant Accounting Pol49

2. Significant Accounting Policies Schedule of Deferred Leasing Costs (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Accounting Policies [Abstract]
Leasing costs	$ 53,556	$ 50,503
Accumulated amortization	(33,756)	(29,958)
Total	$ 19,800	$ 20,545

2. Significant Accounting Pol50

2. Significant Accounting Policies Schedule of Above and Below Market Lease Intangibles (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Accounting Policies [Abstract]
Lease contracts above market value	$ 20,500	$ 20,500
Accumulated amortization	(15,362)	(14,471)
Lease contracts above market value, net	5,138	6,029
Lease contracts below market value	24,175	24,175
Accumulated Amortization	(21,345)	(20,043)
Lease contracts below market value, net	$ 2,830	$ 4,132

2. Significant Accounting Pol51

2. Significant Accounting Policies Schedule of Redeemable Noncontrolling Interests - Operating Partnership (Details) - USD ($) $ in Thousands	2 Months Ended	12 Months Ended
	Feb. 23, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accounting Policies [Abstract]
Beginning Balance, units	13,455,515	15,073,563	15,437,237	15,671,537
Beginning Balance	$ 591,101	$ 479,189	$ 513,134	$ 387,244
Net income attributable to redeemable noncontrolling interests - operating partnership		24,248	(5,993)	18,704
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Noncontrolling Interest		201	0	0
Distributions declared		$ (26,723)	$ (26,513)	$ (22,831)
Redemption of operating partnership units, shares	(1,409,147)	(1,618,048)	(363,674)	(234,300)
Redemption of operating partnership units		$ (64,169)	$ (9,544)	$ (6,100)
Adjustments to redeemable noncontrolling interests – operating partnership		$ 178,757	$ 8,105	$ 136,117
Ending Balance, units		13,455,515	15,073,563	15,437,237
Ending Balance		$ 591,101	$ 479,189	$ 513,134

2. Significant Accounting Pol52

2. Significant Accounting Policies Schedule of Redeemable Partnership Units (Details) - USD ($) $ in Thousands	2 Months Ended	12 Months Ended
	Feb. 23, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Significant Accounting Policies [Line Items]
Beginning Balance, units	13,455,515	15,073,563	15,437,237	15,671,537
Beginning Balance	$ 591,101	$ 479,189	$ 513,134	$ 387,244
Redemption of operating partnership units, shares	(1,409,147)	(1,618,048)	(363,674)	(234,300)
Redemption of operating partnership units		$ (64,169)	$ (9,544)	$ (6,100)
Ending Balance, units		13,455,515	15,073,563	15,437,237
Ending Balance		$ 591,101	$ 479,189	$ 513,134
Subsidiaries [Member]
Significant Accounting Policies [Line Items]
Beginning Balance, units	13,455,515	15,073,563	15,437,237	15,671,537
Beginning Balance	$ 591,101	$ 479,189	$ 513,134	$ 387,244
Redemption of operating partnership units, shares		(1,618,048)	(363,674)	(234,300)
Redemption of operating partnership units		$ (64,169)	$ (9,544)	$ (6,100)
Adjustments to redeemable partnership units		$ 176,081	$ (24,401)	$ 131,990
Ending Balance, units		13,455,515	15,073,563	15,437,237
Ending Balance		$ 591,101	$ 479,189	$ 513,134

2. Significant Accounting Pol53

2. Significant Accounting Policies Schedule of Net Income Attributable to Controlling Interests and Transfers to Redeemable Noncontrolling Interests – Operating Partnership (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accounting Policies [Abstract]
Net income attributable to controlling interests	$ 157,199	$ 1,907	$ 105,907
Net change in the Company’s common stock and additional paid in capital due to the redemption of OP units and other adjustments to redeemable noncontrolling interests – operating partnership	(114,588)	1,439	(130,017)
Net Income Attributable to Controlling Interests and Transfers from Redeemable Noncontrolling Interests Operating Partnership	$ 42,611	$ 3,346	$ (24,110)

2. Significant Accounting Pol54

2. Significant Accounting Policies Schedule of New Accounting Pronouncement, Early Adoption (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
New Accounting Pronouncement, Early Adoption [Line Items]
Additional paid in capital	$ 766,732	$ 685,042
Retained Earnings (Accumulated Deficit)	$ 0	(79,945)
Adjustments for New Accounting Principle, Early Adoption [Member]
New Accounting Pronouncement, Early Adoption [Line Items]
Additional paid in capital		684,968
Retained Earnings (Accumulated Deficit)		(79,871)
New Accounting Pronouncement, Early Adoption, Effect [Member]
New Accounting Pronouncement, Early Adoption [Line Items]
Additional paid in capital		74
Retained Earnings (Accumulated Deficit)		$ (74)

3. Real Estate Assets Summary o

3. Real Estate Assets Summary of Properties (Details) $ in Thousands, CAD in Millions	12 Months Ended
	Dec. 31, 2016USD ($)a		Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2016CADa	Dec. 31, 2013USD ($)
Real Estate Assets [Line Items]
Land	$ 105,890		$ 94,203
Buildings and improvements	3,018,361		2,736,936
Construction in progress and land held for development	330,983	[1]	300,939
Income producing property	3,124,251		2,831,139
Real Estate, Gross	3,455,234		3,132,078	$ 3,066,297		$ 2,799,010
Gross proceeds from sale of NJ1	125,000
Gain (Loss) on Disposition of Property Plant Equipment	22,833		0	0
Asset Impairment Charges	0		$ 122,500	$ 0
ACC2 [Member]
Real Estate Assets [Line Items]
Land	2,500
Buildings and improvements	156,480
Construction in progress and land held for development
Income producing property	158,980
ACC3 [Member]
Real Estate Assets [Line Items]
Land	1,071
Buildings and improvements	96,080
Construction in progress and land held for development
Income producing property	97,151
ACC4 [Member]
Real Estate Assets [Line Items]
Land	6,600
Buildings and improvements	538,869
Construction in progress and land held for development
Income producing property	545,469
ACC5 [Member]
Real Estate Assets [Line Items]
Land	6,443
Buildings and improvements	299,016
Construction in progress and land held for development
Income producing property	305,459
ACC6 [Member]
Real Estate Assets [Line Items]
Land	5,518
Buildings and improvements	216,829
Construction in progress and land held for development
Income producing property	222,347
ACC7 [Member]
Real Estate Assets [Line Items]
Land	9,753
Buildings and improvements	332,970
Construction in progress and land held for development
Income producing property	342,723
CH1 [Member]
Real Estate Assets [Line Items]
Land	23,611
Buildings and improvements	359,171
Construction in progress and land held for development
Income producing property	382,782
CH2 [Member]
Real Estate Assets [Line Items]
Land	14,392
Buildings and improvements	256,539
Construction in progress and land held for development
Income producing property	270,931
SC1 [Member]
Real Estate Assets [Line Items]
Land	20,202
Buildings and improvements	433,099
Construction in progress and land held for development
Income producing property	453,301
VA3 [Member]
Real Estate Assets [Line Items]
Land	9,000
Buildings and improvements	179,694
Construction in progress and land held for development
Income producing property	188,694
VA4 [Member]
Real Estate Assets [Line Items]
Land	6,800
Buildings and improvements	149,614
Construction in progress and land held for development
Income producing property	$ 156,414
ACC9 [Member]
Real Estate Assets [Line Items]
Area of Land | a	35.4				35.4
Land Available for Development	$ 15,600
ACC11 or Powered-base shell [Member]
Real Estate Assets [Line Items]
Area of Land | a	8.6				8.6
Land Available for Development	$ 4,600
OR1 and OR2 [Member]
Real Estate Assets [Line Items]
Area of Land | a	46.7				46.7
Land Available for Development	$ 11,200
TOR1 [Member]
Real Estate Assets [Line Items]
Land Available for Development	41,600				CAD 54.3
UNITED STATES
Real Estate Assets [Line Items]
Income producing property	3,408,900
CANADA
Real Estate Assets [Line Items]
Income producing property	$ 46,300
[1]	(1)Properties located in Ashburn, VA (ACC8, ACC9, ACC10, and ACC11), Elk Grove Village, IL (CH3), Santa Clara, CA (SC1 Phase III, formerly referred to as SC2), Hillsboro, OR (OR1 and OR2) and Vaughan, ON (TOR1).

3. Real Estate Assets Schedule

3. Real Estate Assets Schedule of Major Components of Properties and Useful Lives (Details)	12 Months Ended
	Dec. 31, 2016
Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	40 years
Electrical Structure Power Distribution Units [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	20 years
Electrical Structure Uninterrupted Power Supply [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	25 years
Electrical Structure Switchgear Or Transformers [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	30 years
Fire Protection [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	40 years
Security Systems [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	20 years
Mechanical Structure Heating Ventilating And Air Conditioning [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	20 years
Mechanical Structure Chiller Pumps Or Building Automation [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	25 years
Mechanical Structure Chilled Water Storage And Pipes [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	30 years

4. Intangible Assets and Liab57

4. Intangible Assets and Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Total	$ 19,800	$ 20,545
Leasing Costs [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Life	6 years 329 days
2,017	$ 4,200
2,018	3,854
2,019	2,778
2,020	2,235
2,021	1,752
2022 and thereafter	4,981
Total	19,800
Lease Contracts
Finite-Lived Intangible Assets [Line Items]
2,017	467
2,018	35
2,019	(480)
2,020	(644)
2,021	(570)
2022 and thereafter	(1,116)
Total	$ (2,308)
Tenant Origination Costs [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Life	1 year 219 days
2,017	$ 1,243
2,018	746
Total	$ 1,989
Above Market Leases [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Life	6 years 329 days
Below Market Leases [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Life	3 years 183 days

5. Leases (Details)

5. Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Capital Leased Assets [Line Items]
Deferred rent, net	$ 123,058	$ 128,941
Microsoft [Member]
Capital Leased Assets [Line Items]
Deferred rent, net	(2,000)	(5,200)
Prepaid rents	13,500	9,800
Facebook [Member]
Capital Leased Assets [Line Items]
Deferred rent, net	38,500	42,500
Prepaid rents	8,400	6,800
Fortune 25 Investment Grade-Rated Company [Member]
Capital Leased Assets [Line Items]
Deferred rent, net	11,700	8,500
Prepaid rents	$ 5,200	$ 3,200

5. Leases Schedule of Customers

5. Leases Schedule of Customers Comprising More Than 10% Of Consolidated Revenues (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Microsoft [Member]
Property Subject to or Available for Operating Lease [Line Items]
Customers Comprising More Than Ten Percentage Of Consolidated Revenues	0.297	0.252	0.216
Facebook [Member]
Property Subject to or Available for Operating Lease [Line Items]
Customers Comprising More Than Ten Percentage Of Consolidated Revenues	0.176	0.169	0.174
Fortune 25 Investment Grade-Rated Company [Member]
Property Subject to or Available for Operating Lease [Line Items]
Customers Comprising More Than Ten Percentage Of Consolidated Revenues	0.103	0.065	0.047
Minimum [Member]
Property Subject to or Available for Operating Lease [Line Items]
Customers Comprising More Than Ten Percentage Of Consolidated Revenues	0.100

5. Leases Schedule of Operating

5. Leases Schedule of Operating Lease Future Minimum Lease Payments (Details) $ in Thousands	Dec. 31, 2016USD ($)
Schedule of Operating Lease Future Minimum Lease Payments [Line Items]
2,017	$ 365,642
2,018	358,439
2,019	292,355
2,020	239,842
2,021	219,023
2022 and thereafter	751,080
Total	$ 2,226,381

6. Debt Summary (Details)

6. Debt Summary (Details) $ in Thousands	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Debt Instrument [Line Items]
Mortgage notes payable	$ 110,733	$ 114,075
Unsecured Term Loan	249,036	249,172
Unsecured notes payable	837,323	834,963
Unsecured Credit Facility	50,926	0
Long-term Debt, Gross	$ 1,262,176	1,215,000
Total Debt in Percentage	100.00%
Debt, Weighted Average Interest Rate	4.70%
Long Term Debt, Weighted Average Maturity in Years	4.8
Fixed Rate Debt [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Fixed Interest, Amount	$ 850,000	850,000
Percentage of Total Debt	67.00%
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate	5.80%
FixedInterestDebtMaturityInYears	5.2
Unsecured Notes due 2021 [Member]
Debt Instrument [Line Items]
Unsecured notes payable		600,000
Percentage of Total Debt	47.00%
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate	5.875%
Unsecured Debt Maturity, in Years	4.7
Unsecured Notes due 2023 [Member]
Debt Instrument [Line Items]
Unsecured notes payable	$ 250,000	250,000
Percentage of Total Debt	20.00%
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate	5.625%
Unsecured Debt Maturity, in Years	6.5
Floating Rate Debt [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Amount	$ 412,176	365,000
Percentage of Total Debt	33.00%
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate	2.30%
VariableInterestDebtMaturityInYears	3.8
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Unsecured Credit Facility	$ 50,926	0
Percentage of Total Debt	4.00%
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate	2.40%
Unsecured Debt Maturity, in Years	3.6
Unsecured Term Loan [Member]
Debt Instrument [Line Items]
Unsecured Term Loan	$ 250,000	250,000
Percentage of Total Debt	20.00%
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate	2.30%
Unsecured Debt Maturity, in Years	5.1
AccThreeTermLoan [Member]
Debt Instrument [Line Items]
Term Loan	$ 111,250	115,000
Percentage of Total Debt	9.00%
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate	2.30%
Secured Debt Maturity, in Years	1.2
Secured Debt [Member]
Debt Instrument [Line Items]
Mortgage notes payable	$ 111,250	115,000
Percentage of Total Debt	9.00%
Long-Term Debt, Secured Interest Rate	2.30%
Secured Debt Maturity, in Years	1.2
Unsecured Debt [Member]
Debt Instrument [Line Items]
Unsecured Term Loan	$ 1,150,926	$ 1,100,000
Percentage of Total Debt	91.00%
Long-Term Debt, Unsecured Interest Rate	4.90%
Unsecured Debt Maturity, in Years	5.1
Unsecured Notes due 2023 [Member]
Debt Instrument [Line Items]
Unsecured notes payable	$ 250,000
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate	5.625%
Debt Instrument, Unamortized Discount	$ 1,700

6. Debt Unsecured Credit Facili

6. Debt Unsecured Credit Facility (Details) $ in Thousands, CAD in Millions	12 Months Ended
	Dec. 31, 2016USD ($)	Feb. 23, 2017USD ($)	Feb. 23, 2017CAD	Dec. 31, 2016CAD	Dec. 31, 2015USD ($)
Debt Instrument [Line Items]
Unsecured Credit Facility	$ 50,926				$ 0
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity	750,000
Line of Credit Facility, Maximum Borrowing Capacity	$ 1,250,000
Debt Instrument, Maturity Date	Jul. 25, 2020
Facility amount available for Letters of Credit	$ 35,000
Letters of Credit Outstanding, Amount	0
Unsecured Credit Facility	$ 50,900
Revolving Credit Facility [Member] | Maximum [Member]
Debt Instrument [Line Items]
Unsecured Debt To Unencumbered Assets	60.00%
UnsecuredDebtToUnencumberedAssetsAfterMaterialAcquistion	65.00%
Ratio of Total Indebtedness To Gross Assets Value	60.00%
Consolidated Total Indebtedness To Gross Assets Value Ratio After Material Acquisition	65.00%
Unhedged Variable Rate Debt To Gross Asset Value Ratio	30.00%
Revolving Credit Facility [Member] | Minimum [Member]
Debt Instrument [Line Items]
Income from Unencumbered Assets To Unsecured Debt	12.50%
Income from Unencumbered Assets To Unsecured Debt After Material Acquisition	10.00%
Fixed Charge Coverage Ratio	1.70
Tangible Net Worth Amount	$ 2,300,000
Percentage Of Equity Offerings And Interests In Operating Partnerships To Be Added To Tangible Net Worth Threshold	75.00%
Subsequent Event [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Unsecured Credit Facility		$ 107,100
Domestic Line of Credit [Member]
Debt Instrument [Line Items]
Unsecured Credit Facility	$ 10,000
Domestic Line of Credit [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Unsecured Credit Facility		$ 60,000
Foreign Line of Credit [Member]
Debt Instrument [Line Items]
Unsecured Credit Facility | CAD				CAD 55
Foreign Line of Credit [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity	$ 185,000			CAD 250
Foreign Line of Credit [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Unsecured Credit Facility | CAD			CAD 62

6. Debt Applicable Margin of Un

6. Debt Applicable Margin of Unsecured Credit Facility (Details) - Revolving Credit Facility [Member]	12 Months Ended
	Dec. 31, 2016
Maximum [Member]
Debt Instrument [Line Items]
Ratio of Total Indebtedness To Gross Assets Value	60.00%
Pricing Level 1 [Member] | Maximum [Member]
Debt Instrument [Line Items]
Ratio of Total Indebtedness To Gross Assets Value	35.00%
Pricing Level 2 [Member] | Maximum [Member]
Debt Instrument [Line Items]
Ratio of Total Indebtedness To Gross Assets Value	40.00%
Pricing Level 2 [Member] | Minimum [Member]
Debt Instrument [Line Items]
Ratio of Total Indebtedness To Gross Assets Value	35.00%
Pricing Level 3 [Member] | Maximum [Member]
Debt Instrument [Line Items]
Ratio of Total Indebtedness To Gross Assets Value	45.00%
Pricing Level 3 [Member] | Minimum [Member]
Debt Instrument [Line Items]
Ratio of Total Indebtedness To Gross Assets Value	40.00%
Pricing Level 4 [Member] | Maximum [Member]
Debt Instrument [Line Items]
Ratio of Total Indebtedness To Gross Assets Value	52.50%
Pricing Level 4 [Member] | Minimum [Member]
Debt Instrument [Line Items]
Ratio of Total Indebtedness To Gross Assets Value	45.00%
Pricing Level 5 [Member] | Minimum [Member]
Debt Instrument [Line Items]
Ratio of Total Indebtedness To Gross Assets Value	52.50%
London Interbank Offered Rate (LIBOR) [Member] | Pricing Level 1 [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.55%
London Interbank Offered Rate (LIBOR) [Member] | Pricing Level 2 [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.65%
London Interbank Offered Rate (LIBOR) [Member] | Pricing Level 3 [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.80%
London Interbank Offered Rate (LIBOR) [Member] | Pricing Level 4 [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.95%
London Interbank Offered Rate (LIBOR) [Member] | Pricing Level 5 [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	2.15%
Base Rate [Member] | Pricing Level 1 [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.55%
Base Rate [Member] | Pricing Level 2 [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.65%
Base Rate [Member] | Pricing Level 3 [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.80%
Base Rate [Member] | Pricing Level 4 [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.95%
Base Rate [Member] | Pricing Level 5 [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.15%

6. Debt Credit Rating for Unsec

6. Debt Credit Rating for Unsecured Credit Facility (Details) - Revolving Credit Facility [Member]	12 Months Ended
	Dec. 31, 2016
London Interbank Offered Rate (LIBOR) [Member] | Credit Rating Level 1 [Member] | Moody's, A3 Rating [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.85%
London Interbank Offered Rate (LIBOR) [Member] | Credit Rating Level 2 [Member] | Moody's, Baa1 Rating [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.90%
London Interbank Offered Rate (LIBOR) [Member] | Credit Rating Level 3 [Member] | Moody's, Baa2 Rating [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.00%
London Interbank Offered Rate (LIBOR) [Member] | Credit Rating Level 4 [Member] | Moody's, Baa3 Rating [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.20%
London Interbank Offered Rate (LIBOR) [Member] | Credit Rating Level 5 [Member] | Moody's, Baa3 Rating [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.55%
Base Rate [Member] | Credit Rating Level 1 [Member] | Moody's, A3 Rating [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.00%
Base Rate [Member] | Credit Rating Level 2 [Member] | Moody's, Baa1 Rating [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.00%
Base Rate [Member] | Credit Rating Level 3 [Member] | Moody's, Baa2 Rating [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.00%
Base Rate [Member] | Credit Rating Level 4 [Member] | Moody's, Baa3 Rating [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.20%
Base Rate [Member] | Credit Rating Level 5 [Member] | Moody's, Baa3 Rating [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.55%

6. Debt Unsecured Term Loan (De

6. Debt Unsecured Term Loan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Unsecured Term Loan	$ 249,036	$ 249,172
Unsecured Term Loan [Member]
Debt Instrument [Line Items]
Unsecured Term Loan	$ 250,000
Debt Instrument, Maturity Date	Jan. 21, 2022
Unsecured Term Loan [Member] | Maximum [Member]
Debt Instrument [Line Items]
Unsecured Debt To Unencumbered Assets	60.00%
UnsecuredDebtToUnencumberedAssetsAfterMaterialAcquistion	65.00%
Ratio of Total Indebtedness To Gross Assets Value	60.00%
Consolidated Total Indebtedness To Gross Assets Value Ratio After Material Acquisition	65.00%
Unhedged Variable Rate Debt To Gross Asset Value Ratio	30.00%
Unsecured Term Loan [Member] | Minimum [Member]
Debt Instrument [Line Items]
Income from Unencumbered Assets To Unsecured Debt	12.50%
Income from Unencumbered Assets To Unsecured Debt After Material Acquisition	10.00%
Fixed Charge Coverage Ratio	1.70
Tangible Net Worth Amount	$ 2,300,000
Percentage Of Equity Offerings And Interests In Operating Partnerships To Be Added To Tangible Net Worth Threshold	75.00%

6. Debt Applicable Margin of 66

6. Debt Applicable Margin of Unsecured Term Loan (Details) - Unsecured Term Loan [Member]	12 Months Ended
	Dec. 31, 2016
Maximum [Member]
Debt Instrument [Line Items]
Ratio of Total Indebtedness To Gross Assets Value	60.00%
Maximum [Member] | Pricing Level 1 [Member]
Debt Instrument [Line Items]
Ratio of Total Indebtedness To Gross Assets Value	35.00%
Maximum [Member] | Pricing Level 2 [Member]
Debt Instrument [Line Items]
Ratio of Total Indebtedness To Gross Assets Value	40.00%
Maximum [Member] | Pricing Level 3 [Member]
Debt Instrument [Line Items]
Ratio of Total Indebtedness To Gross Assets Value	45.00%
Maximum [Member] | Pricing Level 4 [Member]
Debt Instrument [Line Items]
Ratio of Total Indebtedness To Gross Assets Value	52.50%
Minimum [Member] | Pricing Level 2 [Member]
Debt Instrument [Line Items]
Ratio of Total Indebtedness To Gross Assets Value	35.00%
Minimum [Member] | Pricing Level 3 [Member]
Debt Instrument [Line Items]
Ratio of Total Indebtedness To Gross Assets Value	40.00%
Minimum [Member] | Pricing Level 4 [Member]
Debt Instrument [Line Items]
Ratio of Total Indebtedness To Gross Assets Value	45.00%
Minimum [Member] | Pricing Level 5 [Member]
Debt Instrument [Line Items]
Ratio of Total Indebtedness To Gross Assets Value	52.50%
London Interbank Offered Rate (LIBOR) [Member] | Pricing Level 1 [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.50%
London Interbank Offered Rate (LIBOR) [Member] | Pricing Level 2 [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.60%
London Interbank Offered Rate (LIBOR) [Member] | Pricing Level 3 [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.75%
London Interbank Offered Rate (LIBOR) [Member] | Pricing Level 4 [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.90%
London Interbank Offered Rate (LIBOR) [Member] | Pricing Level 5 [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	2.10%
Base Rate [Member] | Pricing Level 1 [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.50%
Base Rate [Member] | Pricing Level 2 [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.60%
Base Rate [Member] | Pricing Level 3 [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.75%
Base Rate [Member] | Pricing Level 4 [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.90%
Base Rate [Member] | Pricing Level 5 [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.10%

6. Debt Credit Rating for Uns67

6. Debt Credit Rating for Unsecured Term Loan (Details) - Unsecured Term Loan [Member]	12 Months Ended
	Dec. 31, 2016
London Interbank Offered Rate (LIBOR) [Member] | Credit Rating Level 1 [Member] | Moody's, A3 Rating [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.825%
London Interbank Offered Rate (LIBOR) [Member] | Credit Rating Level 2 [Member] | Moody's, Baa1 Rating [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.875%
London Interbank Offered Rate (LIBOR) [Member] | Credit Rating Level 3 [Member] | Moody's, Baa2 Rating [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.00%
London Interbank Offered Rate (LIBOR) [Member] | Credit Rating Level 4 [Member] | Moody's, Baa3 Rating [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.25%
London Interbank Offered Rate (LIBOR) [Member] | Credit Rating Level 5 [Member] | Moody's, Baa3 Rating [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.65%
Base Rate [Member] | Credit Rating Level 1 [Member] | Moody's, A3 Rating [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.00%
Base Rate [Member] | Credit Rating Level 2 [Member] | Moody's, Baa1 Rating [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.00%
Base Rate [Member] | Credit Rating Level 3 [Member] | Moody's, Baa2 Rating [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.00%
Base Rate [Member] | Credit Rating Level 4 [Member] | Moody's, Baa3 Rating [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.25%
Base Rate [Member] | Credit Rating Level 5 [Member] | Moody's, Baa3 Rating [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.65%

6. Debt ACC3 Term Loan (Details

6. Debt ACC3 Term Loan (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Debt Instrument [Line Items]
Mortgage notes payable	$ 110,733	$ 114,075
AccThreeTermLoan [Member]
Debt Instrument [Line Items]
Mortgage notes payable	$ 111,250
Debt Instrument, Maturity Date	Mar. 27, 2018
AccThreeTermLoan [Member] | Maximum [Member]
Debt Instrument [Line Items]
Ratio of Total Indebtedness To Gross Assets Value	60.00%
AccThreeTermLoan [Member] | Minimum [Member]
Debt Instrument [Line Items]
Fixed Charge Coverage Ratio	1.70
Tangible Net Worth Amount	$ 1,300,000
Percentage Of Equity Offerings And Interests In Operating Partnerships To Be Added To Tangible Net Worth Threshold	80.00%
Debt Service Coverage Ratio	1.50
London Interbank Offered Rate (LIBOR) [Member] | AccThreeTermLoan [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.55%
Base Rate [Member] | AccThreeTermLoan [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.55%

6. Debt Unsecured Notes due 202

6. Debt Unsecured Notes due 2021 (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Unsecured notes payable	$ 837,323	$ 834,963
Unsecured Notes due 2021 [Member]
Debt Instrument [Line Items]
Debt Instrument, Issuance Date	Sep. 24, 2013
Unsecured notes payable	$ 600,000
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate	5.875%
Debt Instrument, Maturity Date	Sep. 15, 2021
Unencumbered Assets to Unsecured Debt	150.00%
Unsecured Notes due 2021 [Member] | Debt Instrument, Redemption, Period Two [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage	104.406%
Unsecured Notes due 2021 [Member] | Debt Instrument, Redemption, Period Three [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage	102.938%
Unsecured Notes due 2021 [Member] | Debt Instrument, Redemption, Period Four [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage	101.469%
Unsecured Notes due 2021 [Member] | Debt Instrument, Redemption, Period Five [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage	100.00%
Unsecured Notes due 2021 [Member] | Change in Control [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage	101.00%
Unsecured Notes due 2021 [Member] | Asset Sales [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage	100.00%

6. Debt Unsecured Notes due 270

6. Debt Unsecured Notes due 2023 (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Unsecured notes payable	$ 837,323	$ 834,963
Unsecured Notes due 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Issuance Date	Jun. 9, 2015
Unsecured notes payable	$ 250,000
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate	5.625%
Public offering price per note	99.205%
Debt Instrument, Maturity Date	Jun. 15, 2023
Unencumbered Assets to Unsecured Debt	150.00%
Unsecured Notes due 2023 [Member] | Debt Instrument, Redemption, Period One [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage	100.00%
Unsecured Notes due 2023 [Member] | Debt Instrument, Redemption, Period Two [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage	104.219%
Unsecured Notes due 2023 [Member] | Debt Instrument, Redemption, Period Three [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage	102.813%
Unsecured Notes due 2023 [Member] | Debt Instrument, Redemption, Period Four [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage	101.406%
Unsecured Notes due 2023 [Member] | Debt Instrument, Redemption, Period Five [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage	100.00%
Unsecured Notes due 2023 [Member] | Change in Control [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage	101.00%
Unsecured Notes due 2023 [Member] | Asset Sales [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage	100.00%

6. Debt Maturity Summary (Detai

6. Debt Maturity Summary (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 1,262,176	$ 1,215,000
Total Debt in Percentage	100.00%
Debt, Weighted Average Interest Rate	4.70%
2017 [Member]
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Principal	$ 8,750
Percentage of Total Debt	0.70%
Debt, Weighted Average Interest Rate	2.30%
2018 [Member]
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Principal	$ 102,500
Percentage of Total Debt	8.10%
Debt, Weighted Average Interest Rate	2.30%
2019 [Member]
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Principal	$ 0
Percentage of Total Debt	0.00%
Debt, Weighted Average Interest Rate	0.00%
2020 [Member]
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Principal	$ 50,926
Percentage of Total Debt	4.10%
Debt, Weighted Average Interest Rate	2.40%
2021 [Member]
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Principal	$ 600,000
Percentage of Total Debt	47.50%
Debt, Weighted Average Interest Rate	5.90%
2022 [Member]
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Principal	$ 250,000
Percentage of Total Debt	19.80%
Debt, Weighted Average Interest Rate	2.30%
2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Principal	$ 250,000
Percentage of Total Debt	19.80%
Debt, Weighted Average Interest Rate	5.60%
Unsecured Notes due 2021 [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate	5.875%
Debt Instrument, Maturity Date	Sep. 15, 2021
Unsecured Notes due 2023 [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate	5.625%
Debt Instrument, Maturity Date	Jun. 15, 2023
Debt Instrument, Unamortized Discount	$ 1,700
AccThreeTermLoan [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	Mar. 27, 2018
AccThreeTermLoan [Member] | BeginningAprilOneTwoThousandSixteen [Member]
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Principal	$ 1,250
Debt Instrument, Date of First Required Payment	Apr. 1, 2016
AccThreeTermLoan [Member] | BeginningAprilOneTwoThousandSeventeen [Member]
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Principal	$ 2,500
Debt Instrument, Date of Increased Required Payment	Apr. 1, 2017
Unsecured Term Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	Jan. 21, 2022
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	Jul. 25, 2020
Fixed Rate Debt [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Fixed Interest, Amount	$ 850,000	850,000
Percentage of Total Debt	67.00%
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate	5.80%
Fixed Rate Debt [Member] | 2017 [Member]
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Principal	$ 0
Fixed Rate Debt [Member] | 2018 [Member]
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Principal	0
Fixed Rate Debt [Member] | 2019 [Member]
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Principal	0
Fixed Rate Debt [Member] | 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Principal	0
Fixed Rate Debt [Member] | 2021 [Member]
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Principal	600,000
Fixed Rate Debt [Member] | 2022 [Member]
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Principal	0
Fixed Rate Debt [Member] | 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Principal	250,000
Floating Rate Debt [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Amount	$ 412,176	$ 365,000
Percentage of Total Debt	33.00%
Floating Rate Debt [Member] | 2017 [Member]
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Principal	$ 8,750
Floating Rate Debt [Member] | 2018 [Member]
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Principal	102,500
Floating Rate Debt [Member] | 2019 [Member]
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Principal	0
Floating Rate Debt [Member] | 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Principal	50,926
Floating Rate Debt [Member] | 2021 [Member]
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Principal	0
Floating Rate Debt [Member] | 2022 [Member]
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Principal	250,000
Floating Rate Debt [Member] | 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Principal	$ 0

7. Related Party Transactions72

7. Related Party Transactions (Details) $ in Millions	12 Months Ended
	Dec. 31, 2016USD ($)aRate	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party | $	$ 0.3	$ 0.4	$ 0.4
Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Ownership Interest	84.90%
Executive Vice President [Member]
Related Party Transaction [Line Items]
Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Ownership Interest	1.00%
ACC9 [Member]
Related Party Transaction [Line Items]
Area of Land | a	35.4
Land Available for Development | $	$ 15.6
Due from Other Related Parties | $	$ 0.3
ACC9 [Member] | Board of Directors Chairman [Member]
Related Party Transaction [Line Items]
Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Ownership Interest	7.00%
ACC9 [Member] | Former CEO [Member]
Related Party Transaction [Line Items]
Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Ownership Interest	1.00%
ACC11 or Powered-base shell [Member]
Related Party Transaction [Line Items]
Area of Land | a	8.6
Land Available for Development | $	$ 4.6
ACC11 or Powered-base shell [Member] | Board of Directors Chairman [Member]
Related Party Transaction [Line Items]
Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Ownership Interest	23.00%
ACC11 or Powered-base shell [Member] | Former CEO [Member]
Related Party Transaction [Line Items]
Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Ownership Interest	18.00%
ACC11 or Powered-base shell [Member] | Director [Member]
Related Party Transaction [Line Items]
Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Ownership Interest	4.00%

8. Commitments and Contingenc73

8. Commitments and Contingencies (Details) $ in Millions	12 Months Ended
	Dec. 31, 2016USD ($)
Long-term Purchase Commitment [Line Items]
Percentage Of Built In Gain That Can Be Recognized Without Triggering Tax Protection Provisions	100.00%
Initial Built In Gain	$ 667
Increase in Percentage of Built In Gain That Can Be Recognized Each Year Without Triggering Tax Protection Provisions	10.00%
Percentage Of Built In Gain That Can Be Recognized In Two Thousand Seventeen Without Triggering Tax Protection Provisions	100.00%
Built in Gain Amount Tax Protected, No Guarantee on Secured Loan	$ 57
Percentage of Disinterested Members of Board for Approving Sales Resulting in Payments to Executives or Directors	75.00%
ACC7 Phase IV [Member]
Long-term Purchase Commitment [Line Items]
Estimated Control Cost	$ 33.3
Amount of Control Estimate Incurred	31.7
Total Commitments For Purchase of Equipment And Labor Related to Development	0.1
ACC9 Phase I [Member]
Long-term Purchase Commitment [Line Items]
Estimated Control Cost	168.4
Amount of Control Estimate Incurred	126.9
Total Commitments For Purchase of Equipment And Labor Related to Development	23.5
ACC9 Phase II [Member]
Long-term Purchase Commitment [Line Items]
Estimated Control Cost	63.9
Amount of Control Estimate Incurred	5.2
Total Commitments For Purchase of Equipment And Labor Related to Development	31
SC1 Phase III [Member]
Long-term Purchase Commitment [Line Items]
Estimated Control Cost	149
Amount of Control Estimate Incurred	78.6
Total Commitments For Purchase of Equipment And Labor Related to Development	17.1
CH3 Phase I [Member]
Long-term Purchase Commitment [Line Items]
Estimated Control Cost	190.7
Amount of Control Estimate Incurred	6
Total Commitments For Purchase of Equipment And Labor Related to Development	35.4
ACC10 [Member]
Long-term Purchase Commitment [Line Items]
Estimated Control Cost	52.1
Amount of Control Estimate Incurred	0.1
Total Commitments For Purchase of Equipment And Labor Related to Development	$ 2.3

9. Redeemable noncontrolling 74

9. Redeemable noncontrolling interests operating partnership / Redeemable partnership units (Details) - USD ($) $ / shares in Units, $ in Thousands	2 Months Ended	12 Months Ended
	Feb. 23, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Redeemable noncontrolling interests – operating partnership / Redeemable partnership units [Line Items]
Redeemable noncontrolling interests - operating partnership		$ 591,101	$ 479,189
Share Price		$ 43.93	$ 31.79
Redemption of operating partnership units, shares	1,409,147	1,618,048	363,674	234,300

10. Preferred Stock Preferred S

10. Preferred Stock Preferred Stock Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	Jul. 15, 2016	Jun. 09, 2016	May 27, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Jan. 31, 2012	Oct. 31, 2010
Preferred Stock [Line Items]
Proceeds from Issuance of Redeemable Preferred Stock				$ 194,252	$ 0	$ 0
Series A cumulative redeemable perpetual preferred stock [Member]
Preferred Stock [Line Items]
Preferred stock, shares issued				0	7,400,000			7,400,000
Preferred Stock, Dividend Rate, Percentage				7.875%
Preferred stock, $.001 par value, 50,000,000 shares authorized				$ 0	$ 185,000			$ 185,000
Preferred Stock, Redemption Date		Jun. 9, 2016	May 27, 2016
Stock Redeemed or Called During Period, Shares		4,000,000	3,400,000
Preferred Stock, Redemption Price Per Share				$ 25
Preferred Stock Redemption Premium				$ 6,400
Series B cumulative redeemable perpetual preferred stock [Member]
Preferred Stock [Line Items]
Preferred stock, shares issued				0	6,650,000		6,650,000
Preferred Stock, Dividend Rate, Percentage				7.625%
Preferred stock, $.001 par value, 50,000,000 shares authorized				$ 0	$ 166,250		$ 166,250
Preferred Stock, Redemption Date	Jul. 15, 2016	Jun. 9, 2016
Stock Redeemed or Called During Period, Shares	4,000,000	2,650,000
Preferred Stock, Redemption Price Per Share				$ 25
Preferred Stock Redemption Premium				$ 6,100
Series C cumulative redeemable perpetual preferred stock [Member]
Preferred Stock [Line Items]
Preferred stock, shares issued				8,050,000	0
Preferred Stock, Dividend Rate, Percentage				6.625%
Preferred stock, $.001 par value, 50,000,000 shares authorized				$ 201,250	$ 0
Preferred Stock, Liquidation Preference Per Share				$ 25
Proceeds from Issuance of Redeemable Preferred Stock				$ 194,252
Share Cap to Determine Redemption Price in Change in Control				1.1723

10. Preferred Stock Preferred76

10. Preferred Stock Preferred Stock Schedule of Preferred Stock Dividend (Details) - $ / shares	3 Months Ended												12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Series A Preferred Stock [Member]
Preferred Stock Dividend [Line Items]
Record Date				Apr. 1, 2016	Dec. 30, 2015	Oct. 2, 2015	Jul. 2, 2015	Apr. 2, 2015	Dec. 30, 2014	Oct. 3, 2014	Jul. 3, 2014	Apr. 4, 2014
Payment Date				Apr. 15, 2016	Jan. 15, 2016	Oct. 15, 2015	Jul. 15, 2015	Apr. 15, 2015	Jan. 15, 2015	Oct. 15, 2014	Jul. 15, 2014	Apr. 15, 2014
Cash Dividend				$ 0.4921875	$ 0.4921875	$ 0.4921875	$ 0.4921875	$ 0.4921875	$ 0.4921875	$ 0.4921875	$ 0.4921875	$ 0.4921875	$ 0.4921875	$ 1.9687500	$ 1.9687500
Ordinary Taxable Dividend				0.4921875	0.4921875	0.4921875	0.4921875	0.4921875	0.4921875	0.4921875	0.4921875	0.4921875	0.4921875	1.9687500	1.9687500
Nontaxable Return of Capital Distributions				$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	0	0	0
Series B Preferred Stock [Member]
Preferred Stock Dividend [Line Items]
Record Date			Jul. 1, 2016	Apr. 1, 2016	Dec. 30, 2015	Oct. 2, 2015	Jul. 2, 2015	Apr. 2, 2015	Dec. 30, 2014	Oct. 3, 2014	Jul. 3, 2014	Apr. 4, 2014
Payment Date			Jul. 15, 2016	Apr. 15, 2016	Jan. 15, 2016	Oct. 15, 2015	Jul. 15, 2015	Apr. 15, 2015	Jan. 15, 2015	Oct. 15, 2014	Jul. 15, 2014	Apr. 15, 2014
Cash Dividend			$ 0.4765625	$ 0.4765625	$ 0.4765625	$ 0.4765625	$ 0.4765625	$ 0.4765625	$ 0.4765625	$ 0.4765625	$ 0.4765625	$ 0.4765625	0.9531250	1.9062500	1.9062500
Ordinary Taxable Dividend			0.4765625	0.4765625	0.4765625	0.4765625	0.4765625	0.4765625	0.4765625	0.4765625	0.4765625	0.4765625	0.9531250	1.9062500	1.9062500
Nontaxable Return of Capital Distributions			$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	0	$ 0	$ 0
Series C Preferred Stock [Member]
Preferred Stock Dividend [Line Items]
Record Date		Nov. 1, 2016	Aug. 1, 2016
Payment Date		Nov. 15, 2016	Aug. 15, 2016
Cash Dividend	$ 0.4140625	$ 0.4094618											0.8235243
Ordinary Taxable Dividend	0.4140625	0.4094618											0.8235243
Nontaxable Return of Capital Distributions	$ 0	$ 0											$ 0

11. Stockholders Equity of th77

11. Stockholders Equity of the REIT and Partners Capital of the OP Stockholders Equity of the REIT and Partners Capital of the OP Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	2 Months Ended	3 Months Ended												12 Months Ended
	Feb. 23, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Stockholders’ Equity of the REIT and Partners’ Capital of the OP [Line Items]
Issuance of stock awards, shares														227,430	565,162	163,187
Redemption of operating partnership units, shares	1,409,147													1,618,048	363,674	234,300
Stock Repurchase Program, Authorized Amount						$ 120,000									$ 120,000
Common stock repurchase, shares															1,002,610
Stock Repurchased and Retired During Period, Value															$ 31,912
Stock Issued During Period, Shares, New Issues														7,613,000
Shares Issued, Price Per Share		$ 37.75												$ 37.75
Issuance of common stock, full exercise of underwriters' option														993,000
Stock Issued During Period, Value, New Issues														$ 275,470
Common Stock [Member]
Stockholders’ Equity of the REIT and Partners’ Capital of the OP [Line Items]
Cash Dividend		0.50	$ 0.47	$ 0.47	$ 0.47	$ 0.47	$ 0.42	$ 0.42	$ 0.42	$ 0.42	$ 0.35	$ 0.35	$ 0.35	$ 1.91	$ 1.73	$ 1.47
Ordinary Taxable Dividend		$ 0	$ 0.26	$ 0.26	$ 0.26	$ 0.33	$ 0.42	$ 0.42	$ 0.42	$ 0.390	$ 0.350	$ 0.350	$ 0.350	$ 0.78	$ 1.59	$ 1.440
Stock Issued During Period, Shares, New Issues														7,613,000
January Two Zero One Six [Member] | Common Stock [Member]
Stockholders’ Equity of the REIT and Partners’ Capital of the OP [Line Items]
Ordinary Taxable Dividend														$ 0.14
January Two Zero One Five [Member] | Common Stock [Member]
Stockholders’ Equity of the REIT and Partners’ Capital of the OP [Line Items]
Ordinary Taxable Dividend														$ 0.03

11. Stockholders Equity of th78

11. Stockholders Equity of the REIT and Partners Capital of the OP Stockholders Equity of the REIT and Partners Capital of the OP Schedule of Common Stock Dividend (Details) - Common Stock [Member] - $ / shares	3 Months Ended												12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Class of Stock [Line Items]
Record Date	Dec. 30, 2016	Oct. 7, 2016	Jul. 1, 2016	Apr. 1, 2016	Dec. 30, 2015	Oct. 2, 2015	Jul. 2, 2015	Apr. 2, 2015	Dec. 30, 2014	Oct. 3, 2014	Jul. 3, 2014	Apr. 4, 2014
Payment Date	Jan. 17, 2017	Oct. 17, 2016	Jul. 15, 2016	Apr. 15, 2016	Jan. 16, 2016	Oct. 15, 2015	Jul. 15, 2015	Apr. 15, 2015	Jan. 15, 2015	Oct. 15, 2014	Jul. 15, 2014	Apr. 15, 2014
Cash Dividend	$ 0.50	$ 0.47	$ 0.47	$ 0.47	$ 0.47	$ 0.42	$ 0.42	$ 0.42	$ 0.42	$ 0.35	$ 0.35	$ 0.35	$ 1.91	$ 1.73	$ 1.47
Ordinary Taxable Dividend	0	0.26	0.26	0.26	0.33	0.42	0.42	0.42	0.390	0.350	0.350	0.350	0.78	1.59	1.440
Nontaxable Return of Capital Distributions	$ 0	$ 0.21	$ 0.21	$ 0.21	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0.63	$ 0	$ 0

12. Equity Compensation Plan Na

12. Equity Compensation Plan Narrative (Details) $ / shares in Units, $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2017shares	Dec. 31, 2016USD ($)$ / sharesRateshares	Dec. 31, 2015USD ($)$ / sharesRateshares	Dec. 31, 2014USD ($)$ / sharesshares
Equity Compensation Plan [Line Items]
Maximum Number of Share Equivalents Authorized		6,300,000
Share equivalent ratio, other than stock options and SARs		2.36
Cumulative Share Equivalents Issued From The Plan		3,913,287
Share Equivalents Remaining Available		2,386,713
Shares of restricted stock, Granted		175,410	171,475	149,608
Value of Restricted Stock Awarded during period | $		$ 6	$ 5.5	$ 3.8
Shares of restricted stock, Vested		167,419	138,585	125,798
Value of Restricted Stock on Vesting Date | $		$ 6.2	$ 4.3	$ 3.4
Unearned Compensation on Restricted Stock | $		$ 6.4
Weighted Average Vesting Period		1 year 37 days
Granted		0	0	0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercised, Intrinsic Value | $		$ 5.2	$ 3.7	$ 7.7
Performance units, forfeited		47,958	7,737	3,785
Weighted Average Grant Date Fair Value, Forfeited | $ / shares		$ 30.41	$ 28.71	$ 23.98
Stock Options [Member]
Equity Compensation Plan [Line Items]
Weighted Average Vesting Period		1 day	73 days	183 days
Performance Shares [Member]
Equity Compensation Plan [Line Items]
Shares of restricted stock, Granted		112,951	48,674	110,441
Unearned Compensation on Restricted Stock | $		$ 3.7
Share-based Compensation Arrangement by Share-based Payment Award, Accelerated Vesting, Number			320,676
Share-based Compensation Arrangement by Share-based Payment Award Accelerated Compensation Cost | $			$ 1.9
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period	57,177
Performance units, forfeited		0	4,225	0
Weighted Average Grant Date Fair Value, Forfeited | $ / shares			$ 36.30
Minimum [Member]
Equity Compensation Plan [Line Items]
Potential Number Of Shares Issued At Vesting Of Performance Units		0.00%
Maximum [Member]
Equity Compensation Plan [Line Items]
Performance Units Payout Percentage		150.00%
Potential Number Of Shares Issued At Vesting Of Performance Units			300.00%
Performance Units Granted 2/23/2012 [Member] | Performance Shares [Member]
Equity Compensation Plan [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period			0
Performance Units Payout Percentage | Rate		0.00%
Performance Units Granted 2/21/2013 [Member] | Performance Shares [Member]
Equity Compensation Plan [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period		32,985
Share-based Compensation Award, 300% payout [Member] | Performance Units Granted 2/21/2013 [Member] | Performance Shares [Member]
Equity Compensation Plan [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period			115,437
Share-based Compensation Award, 300% payout [Member] | Performance Units Granted 2/21/2014 [Member] | Performance Shares [Member]
Equity Compensation Plan [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period			205,240
Performance Units Payout Percentage | Rate			300.00%
Share-based Compensation Award, 100% payout [Member] | Performance Units Granted 2/21/2014 [Member] | Performance Shares [Member]
Equity Compensation Plan [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period			2,125
Performance Units Payout Percentage | Rate			100.00%

12. Equity Compensation Plan Su

12. Equity Compensation Plan Summary of Restricted Stock (Details) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Equity Compensation Plan [Line Items]
Shares of restricted stock, Unvested balance at beginning balance	349,142	323,989	303,964
Shares of restricted stock, Granted	175,410	171,475	149,608
Shares of restricted stock, Vested	(167,419)	(138,585)	(125,798)
Shares of restricted stock, Forfeited	(47,958)	(7,737)	(3,785)
Shares of restricted stock, Unvested balance at ending balance	309,175	349,142	323,989
Weighted Average Grant Date Fair Value, Unvested balance at beginning balance	$ 28.02	$ 24.10	$ 22.89
Weighted Average Grant Date Fair Value, Granted	33.96	32.12	25.63
Weighted Average Grant Date Fair Value, Vested	25.66	23.87	23.02
Weighted Average Grant Date Fair Value, Forfeited	30.41	28.71	23.98
Weighted Average Grant Date Fair Value, Unvested balance at ending balance	$ 32.30	$ 28.02	$ 24.10

12. Equity Compensation Plan 81

12. Equity Compensation Plan Summary of Stock Options (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Equity Compensation Plan [Line Items]
Under option, beginning balance	1,230,212	1,592,854	2,099,910
Granted	0	0	0
Exercised	(478,733)	(362,642)	(507,056)
Forfeited	0	0	0
Under option, ending balance	751,479	1,230,212	1,592,854
Weighted Average Exercise Price, Under Option, Beginning balance	$ 18.28	$ 19.09	$ 17.13
Weighted Average Exercise Price, Granted	0	0	0
Weighted Average Exercise Price, Exercised	22.12	21.87	10.95
Weighted Average Exercise Price, Forfeited	0	0	0
Weighted Average Exercise Price, Under Option, Ending balance	$ 15.83	$ 18.28	$ 19.09
Total Unearned Compensation	$ 0	$ 0.1	$ 0.7
Weighted Average Vesting Period	1 year 37 days
Weighted Average Remaining Contractual Term	3 years 219 days	4 years 329 days	6 years 73 days
Stock Options [Member]
Equity Compensation Plan [Line Items]
Weighted Average Vesting Period	1 day	73 days	183 days

12. Equity Compensation Plan 82

12. Equity Compensation Plan Summary of Unvested Stock Options (Details) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Equity Compensation Plan [Line Items]
Unvested balance, beginning balance	38,771	302,324	684,111
Granted	0	0	0
Vested	(38,771)	(263,553)	(381,787)
Forfeited	0	0	0
Unvested balance, ending balance	0	38,771	302,324
Weighted Average Grant Date Fair Value, Unvested at beginning balance	$ 4.75	$ 5.05	$ 5.73
Weighted Average Grant Date Fair Value, Granted	0	0	0
Weighted Average Grant Date Fair Value, Vested	4.75	5.10	6.28
Weighted Average Grant Date Fair Value, Forfeited	0	0	0
Weighted Average Grant Date Fair Value, Unvested at ending balance	$ 0	$ 4.75	$ 5.05

12. Equity Compensation Plan 83

12. Equity Compensation Plan Summary of Exercisable Stock Options (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Equity Compensation Plan [Line Items]
Options Exercisable, beginning balance	1,191,441	1,290,530	1,415,799
Vested	38,771	263,553	381,787
Exercised	(478,733)	(362,642)	(507,056)
Options Exercisable, ending balance	751,479	1,191,441	1,290,530
Weighted Average Grant Date Fair Value, Exercisable at beginning balance	$ 5.41	$ 5.74	$ 4.81
Weighted Average Grant Date Fair Value, Vested	4.75	5.10	6.28
Weighted Average Grant Date Fair Value, Exercised	6.46	6.34	3.54
Weighted Average Grant Date Fair Value, Exercisable at ending balance	$ 4.71	$ 5.41	$ 5.74
Intrinsic Value	$ 21.1	$ 16.3	$ 19.3
Weighted Average Exercise Price	$ 15.83	$ 18.14	$ 18.27
Weighted Average Remaining Contractual Term	3 years 219 days	4 years 329 days	5 years 292 days

12. Equity Compensation Plan 84

12. Equity Compensation Plan Summary of Assumptions Used for Performance Units Granted (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Equity Compensation Plan [Line Items]
Number of performance units granted	175,410	171,475	149,608
Performance Shares [Member]
Equity Compensation Plan [Line Items]
Number of performance units granted	112,951	48,674	110,441
Expected volatility	24.00%	24.00%	30.00%
Expected annual dividend	5.98%	5.00%	5.00%
Risk-free rate	1.32%	1.06%	0.74%
Performance unit fair value at date of grant	$ 38.08	$ 38.34	$ 33.50
Total grant fair value at date of grant (millions)	$ 4.3	$ 1.9	$ 3.7
Maximum value of grant on vesting date based on closing price of the Company's stock at the date of grant	$ 10.7	$ 4.7	$ 8.5
Performance Units Granted 1/5/2016 [Member] | Performance Shares [Member]
Equity Compensation Plan [Line Items]
Performance unit fair value at date of grant	$ 38.08

12. Equity Compensation Plan 85

12. Equity Compensation Plan Summary of Performance Units Outstanding (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Equity Compensation Plan [Line Items]
Total Performance Units Outstanding		309,175	349,142	323,989	303,964
Performance Shares [Member]
Equity Compensation Plan [Line Items]
Performance unit fair value at date of grant		$ 38.08	$ 38.34	$ 33.50
Total Performance Units Granted		393,567
Total Performance Units Vested		60,931
Total Performance Units Accelerated		(109,668)
Total Performance Units Forfeited		26,316
Total Performance Units Outstanding		196,652
Total Shares Issued for Vested Performance Units		356,438
Share-based Compensation Arrangement by Share-based Payment Award, Accelerated Vesting, Number			320,676
Share-based Compensation Arrangement by Share-based Payment Award Accelerated Compensation Cost			$ 1.9
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period	57,177
Performance Units Granted 2/23/2012 [Member] | Performance Shares [Member]
Equity Compensation Plan [Line Items]
Performance unit fair value at date of grant		$ 28.26
Total Performance Units Granted		61,033
Total Performance Units Vested		49,936
Total Performance Units Accelerated		0
Total Performance Units Forfeited		11,097
Total Performance Units Outstanding		0
Performance Units Payout Percentage		0.00%
Total Shares Issued for Vested Performance Units		0
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period			0
Performance Units Granted 2/21/2013 [Member] | Performance Shares [Member]
Equity Compensation Plan [Line Items]
Performance unit fair value at date of grant		$ 25.59
Total Performance Units Granted		60,468
Total Performance Units Vested		10,995
Total Performance Units Accelerated		(38,479)
Total Performance Units Forfeited		10,994
Total Performance Units Outstanding		0
Total Shares Issued for Vested Performance Units		148,422
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period		32,985
Performance Units Granted 2/21/2014 [Member] | Performance Shares [Member]
Equity Compensation Plan [Line Items]
Performance unit fair value at date of grant		$ 33.50
Total Performance Units Granted		110,441
Total Performance Units Vested		0
Total Performance Units Accelerated		(70,538)
Total Performance Units Forfeited		1,785
Total Performance Units Outstanding		38,118
Total Shares Issued for Vested Performance Units		207,365
Performance Units Granted 3/16/2015 [Member] | Performance Shares [Member]
Equity Compensation Plan [Line Items]
Performance unit fair value at date of grant		$ 38.34
Total Performance Units Granted		48,674
Total Performance Units Vested		0
Total Performance Units Accelerated		(651)
Total Performance Units Forfeited		2,440
Total Performance Units Outstanding		45,583
Total Shares Issued for Vested Performance Units		651
Performance Units Granted 1/5/2016 [Member] | Performance Shares [Member]
Equity Compensation Plan [Line Items]
Performance unit fair value at date of grant		$ 38.08
Total Performance Units Granted		112,951
Total Performance Units Vested		0
Total Performance Units Accelerated		0
Total Performance Units Forfeited		0
Total Performance Units Outstanding		112,951
Maximum [Member]
Equity Compensation Plan [Line Items]
Performance Units Payout Percentage		(150.00%)
Potential Number Of Shares Issued At Vesting Of Performance Units			300.00%
Share-based Compensation Award, 300% payout [Member] | Performance Units Granted 2/21/2013 [Member] | Performance Shares [Member]
Equity Compensation Plan [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period			115,437
Share-based Compensation Award, 300% payout [Member] | Performance Units Granted 2/21/2014 [Member] | Performance Shares [Member]
Equity Compensation Plan [Line Items]
Performance Units Payout Percentage			(300.00%)
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period			205,240
Share-based Compensation Award, 100% payout [Member] | Performance Units Granted 2/21/2014 [Member] | Performance Shares [Member]
Equity Compensation Plan [Line Items]
Performance Units Payout Percentage			(100.00%)
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period			2,125

13. Earnings Per Share of the86

13. Earnings Per Share of the REIT (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2016		Sep. 30, 2016		Jun. 30, 2016		Mar. 31, 2016		Dec. 31, 2015		Sep. 30, 2015		Jun. 30, 2015		Mar. 31, 2015		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings per share of the REIT [Line Items]
Weighted average common shares – basic																	73,003,164	65,184,013	65,486,108
Effect of dilutive securities																	835,872	0	600,271
Weighted average common shares – diluted																	73,839,036	65,184,013	66,086,379
Net income attributable to common shares	$ 33,734		$ 28,524		$ 37,299		$ 24,408		$ (79,871)		$ 19,062		$ 19,668		$ 15,803		$ 123,965	$ (25,338)	$ 78,662
Net income allocated to unvested restricted shares																	(628)	(599)	(484)
Net income attributable to common shares, adjusted																	$ 123,337	$ (25,937)	$ 78,178
Earnings per common share – basic	$ 0.45		$ 0.38		$ 0.50		$ 0.36		$ (1.23)	[1]	$ 0.29	[1]	$ 0.30	[1]	$ 0.24	[1]	$ 1.69	$ (0.40)	$ 1.19
Adjusted net income available to common shares																	$ 123,337	$ (25,937)	$ 78,178
Earnings per common share – diluted	$ 0.44	[1]	$ 0.37	[1]	$ 0.49	[1]	$ 0.36	[1]	$ (1.23)		$ 0.29		$ 0.30		$ 0.24		$ 1.67	$ (0.40)	$ 1.18
Equity Option [Member]
Earnings per share of the REIT [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount																	0	600,000	0
Performance Shares [Member]
Earnings per share of the REIT [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount																	100,000	100,000	100,000
[1]	Amounts do not equal full year results due to rounding.

14. Earnings Per Unit of the 87

14. Earnings Per Unit of the Operating Partnership (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings per unit of the Operating Partnership [Line Items]
Weighted average common units – basic (includes redeemable partnership units and units of general and limited partners)	87,284,564	80,599,199	81,053,127
Effect of dilutive securities	835,872	0	600,271
Weighted average common units – diluted	88,120,436	80,599,199	81,653,398
Net income Loss attributable to common units, basic	$ 148,213	$ (31,331)	$ 97,366
Net income allocated to unvested restricted units	(628)	(599)	(484)
Net income attributable to common units, adjusted	$ 147,585	$ (31,930)	$ 96,882
Earnings per unit, basic	$ 1.69	$ (0.40)	$ 1.19
Earnings per unit, diluted	$ 1.67	$ (0.40)	$ 1.18
Subsidiaries [Member]
Earnings per unit of the Operating Partnership [Line Items]
Net income Loss attributable to common units, basic	$ 148,213	$ (31,331)	$ 97,366
Earnings per unit, basic	$ 1.69	$ (0.40)	$ 1.19
Earnings per unit, diluted	$ 1.67	$ (0.40)	$ 1.18
Equity Option [Member]
Earnings per unit of the Operating Partnership [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0	600,000	0
Performance Shares [Member]
Earnings per unit of the Operating Partnership [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	100,000	100,000	100,000

15. Employee Benefit Plan (Deta

15. Employee Benefit Plan (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Employee Benefit Plan [Abstract]
Percentage Of Employees Contribution Contributed By Employer	50.00%
Percentage Of Employee's Salary Contributed By Employer	4.00%
Defined Benefit Plan, Contributions by Employer	$ 0.6	$ 0.5	$ 0.4

16. Fair Value (Details)

16. Fair Value (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Long-term Debt	$ 1,260.5	$ 1,213.1
Long-term Debt, Fair Value	$ 1,291	$ 1,237.2

17. Quarterly Financial Infor90

17. Quarterly Financial Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2016		Sep. 30, 2016		Jun. 30, 2016		Mar. 31, 2016		Dec. 31, 2015		Sep. 30, 2015		Jun. 30, 2015		Mar. 31, 2015		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Total revenues	$ 141,688		$ 134,326		$ 128,538		$ 124,149		$ 115,923		$ 115,337		$ 113,826		$ 107,314		$ 528,701	$ 452,400	$ 417,592
Net (loss) income	43,227		40,966		60,557		36,697		(91,953)		30,393		31,141		26,333		181,447	(4,086)	124,611
Net income attributable to common shares	$ 33,734		$ 28,524		$ 37,299		$ 24,408		$ (79,871)		$ 19,062		$ 19,668		$ 15,803		$ 123,965	$ (25,338)	$ 78,662
Net income attributable to common shares	$ 0.45		$ 0.38		$ 0.50		$ 0.36		$ (1.23)	[1]	$ 0.29	[1]	$ 0.30	[1]	$ 0.24	[1]	$ 1.69	$ (0.40)	$ 1.19
Net income attributable to common shares	$ 0.44	[1]	$ 0.37	[1]	$ 0.49	[1]	$ 0.36	[1]	$ (1.23)		$ 0.29		$ 0.30		$ 0.24		$ 1.67	$ (0.40)	$ 1.18
Gain (Loss) on Disposition of Property Plant Equipment																	$ 22,833	$ 0	$ 0
Asset Impairment Charges																	$ 0	$ 122,500	$ 0
[1]	Amounts do not equal full year results due to rounding.

18. Supplemental Consolidatin91

18. Supplemental Consolidating Financial Data for Subsidiary Guarantors of the Unsecured Notes Supplemental Consolidating Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2016		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Supplemental Consolidating Statements Of Balance Sheets [Line Items]
Land	$ 105,890		$ 94,203
Buildings and improvements	3,018,361		2,736,936
Income producing property	3,124,251		2,831,139
Less: accumulated depreciation	(662,183)		(560,837)
Net income producing property	2,462,068		2,270,302
Construction in progress and land held for development	330,983	[1]	300,939
Net real estate	2,793,051		2,571,241
Cash and cash equivalents	38,624		31,230	$ 29,598	$ 38,733
Rents and other receivables	11,533		9,588
Deferred rent, net	123,058		128,941
Lease contracts above market value, net	5,138		6,029
Deferred costs, net	25,776		23,774
Prepaid expenses and other assets	41,284		44,689
Total assets	3,038,464		2,815,492
Unsecured Credit Facility	50,926		0
Mortgage notes payable	110,733		114,075
Unsecured Term Loan	249,036		249,172
Unsecured notes payable	837,323		834,963
Accounts payable and accrued liabilities	36,909		32,301
Construction costs payable	56,428		22,043
Accrued interest payable	11,592		11,821
Distribution payable	46,352		43,906
Lease contracts below market value, net	2,830		4,132
Prepaid rents and other liabilities	78,232		67,477
Total liabilities	1,480,361		1,379,890
Redeemable noncontrolling interests - operating partnership	591,101		479,189
Commitments and contingencies	0		0
Total liabilities and stockholders’ equity	3,038,464		2,815,492
Subsidiaries [Member]
Supplemental Consolidating Statements Of Balance Sheets [Line Items]
Land	105,890		94,203
Buildings and improvements	3,018,361		2,736,936
Income producing property	3,124,251		2,831,139
Less: accumulated depreciation	(662,183)		(560,837)
Net income producing property	2,462,068		2,270,302
Construction in progress and land held for development	330,983		300,939
Net real estate	2,793,051		2,571,241
Cash and cash equivalents	34,409		27,015	25,380	34,514
Rents and other receivables	11,533		9,588
Deferred rent, net	123,058		128,941
Lease contracts above market value, net	5,138		6,029
Deferred costs, net	25,776		23,774
Investment in affiliates	0		0
Prepaid expenses and other assets	41,284		44,689
Total assets	3,034,249		2,811,277
Unsecured Credit Facility	50,926		0
Mortgage notes payable	110,733		114,075
Unsecured Term Loan	249,036		249,172
Unsecured notes payable	837,323		834,963
Accounts payable and accrued liabilities	36,909		32,301
Construction costs payable	56,428		22,043
Accrued interest payable	11,592		11,821
Distribution payable	46,352		43,906
Lease contracts below market value, net	2,830		4,132
Prepaid rents and other liabilities	78,232		67,477
Total liabilities	1,480,361		1,379,890
Redeemable noncontrolling interests - operating partnership	591,101		479,189
Commitments and contingencies	0		0
Limited Partners' Capital	201,250
General Partners' Capital	6,645		6,021
Total partners’ capital	962,787		952,198	1,111,123	1,248,055
Total liabilities and stockholders’ equity	3,034,249		2,811,277
Subsidiaries [Member] | Operating Partnership [Member]
Supplemental Consolidating Statements Of Balance Sheets [Line Items]
Land	0		0
Buildings and improvements	0		0
Income producing property	0		0
Less: accumulated depreciation	0		0
Net income producing property	0		0
Construction in progress and land held for development	0		0
Net real estate	0		0
Cash and cash equivalents	31,781		21,697	21,806	32,903
Rents and other receivables	1,390		1,391
Deferred rent, net	0		0
Lease contracts above market value, net	0		0
Deferred costs, net	6,066		3,236
Investment in affiliates	2,713,096		2,546,465
Prepaid expenses and other assets	3,463		3,025
Total assets	2,755,796		2,575,814
Unsecured Credit Facility	50,926		0
Mortgage notes payable	0		0
Unsecured Term Loan	249,036		249,172
Unsecured notes payable	837,323		834,963
Accounts payable and accrued liabilities	6,477		4,516
Construction costs payable	0		43
Accrued interest payable	11,578		11,815
Distribution payable	46,352		43,906
Lease contracts below market value, net	0		0
Prepaid rents and other liabilities	216		12
Total liabilities	1,201,908		1,144,427
Redeemable noncontrolling interests - operating partnership	591,101		479,189
Commitments and contingencies	0		0
General Partners' Capital	6,645		6,021
Total partners’ capital	962,787		952,198
Total liabilities and stockholders’ equity	2,755,796		2,575,814
Subsidiaries [Member] | Subsidiary Guarantors [Member]
Supplemental Consolidating Statements Of Balance Sheets [Line Items]
Land	80,673		84,258
Buildings and improvements	2,332,771		2,399,016
Income producing property	2,413,444		2,483,274
Less: accumulated depreciation	(605,488)		(522,096)
Net income producing property	1,807,956		1,961,178
Construction in progress and land held for development	88,836		25,545
Net real estate	1,896,792		1,986,723
Cash and cash equivalents	0		0	0	0
Rents and other receivables	4,743		7,563
Deferred rent, net	109,142		122,830
Lease contracts above market value, net	5,138		6,029
Deferred costs, net	11,632		14,250
Investment in affiliates	0		0
Prepaid expenses and other assets	27,341		39,642
Total assets	2,054,788		2,177,037
Unsecured Credit Facility	0		0
Mortgage notes payable	0		0
Unsecured Term Loan	0		0
Unsecured notes payable	0		0
Accounts payable and accrued liabilities	22,319		23,615
Construction costs payable	10,159		293
Accrued interest payable	0		0
Distribution payable	0		0
Lease contracts below market value, net	2,830		4,132
Prepaid rents and other liabilities	58,599		62,630
Total liabilities	93,907		90,670
Redeemable noncontrolling interests - operating partnership	0		0
Commitments and contingencies	0		0
General Partners' Capital	0		0
Total partners’ capital	1,960,881		2,086,367
Total liabilities and stockholders’ equity	2,054,788		2,177,037
Subsidiaries [Member] | Subsidiary Non-Guarantors [Member]
Supplemental Consolidating Statements Of Balance Sheets [Line Items]
Land	25,217		9,945
Buildings and improvements	685,590		337,920
Income producing property	710,807		347,865
Less: accumulated depreciation	(56,695)		(38,741)
Net income producing property	654,112		309,124
Construction in progress and land held for development	242,147		275,394
Net real estate	896,259		584,518
Cash and cash equivalents	2,628		5,318	3,574	1,611
Rents and other receivables	5,400		634
Deferred rent, net	13,916		6,111
Lease contracts above market value, net	0		0
Deferred costs, net	8,078		6,288
Investment in affiliates	0		0
Prepaid expenses and other assets	10,480		2,022
Total assets	936,761		604,891
Unsecured Credit Facility	0		0
Mortgage notes payable	110,733		114,075
Unsecured Term Loan	0		0
Unsecured notes payable	0		0
Accounts payable and accrued liabilities	8,113		4,170
Construction costs payable	46,269		21,707
Accrued interest payable	14		6
Distribution payable	0		0
Lease contracts below market value, net	0		0
Prepaid rents and other liabilities	19,417		4,835
Total liabilities	184,546		144,793
Redeemable noncontrolling interests - operating partnership	0		0
Commitments and contingencies	0		0
General Partners' Capital	0		0
Total partners’ capital	752,215		460,098
Total liabilities and stockholders’ equity	936,761		604,891
Subsidiaries [Member] | Eliminations [Member]
Supplemental Consolidating Statements Of Balance Sheets [Line Items]
Land	0		0
Buildings and improvements	0		0
Income producing property	0		0
Less: accumulated depreciation	0		0
Net income producing property	0		0
Construction in progress and land held for development	0		0
Net real estate	0		0
Cash and cash equivalents	0		0	$ 0	$ 0
Rents and other receivables	0		0
Deferred rent, net	0		0
Lease contracts above market value, net	0		0
Deferred costs, net	0		0
Investment in affiliates	(2,713,096)		(2,546,465)
Prepaid expenses and other assets	0		0
Total assets	(2,713,096)		(2,546,465)
Unsecured Credit Facility	0		0
Mortgage notes payable	0		0
Unsecured Term Loan	0		0
Unsecured notes payable	0		0
Accounts payable and accrued liabilities	0		0
Construction costs payable	0		0
Accrued interest payable	0		0
Distribution payable	0		0
Lease contracts below market value, net	0		0
Prepaid rents and other liabilities	0		0
Total liabilities	0		0
Redeemable noncontrolling interests - operating partnership	0		0
Commitments and contingencies	0		0
General Partners' Capital	0		0
Total partners’ capital	(2,713,096)		(2,546,465)
Total liabilities and stockholders’ equity	(2,713,096)		(2,546,465)
Subsidiaries [Member] | Series A Preferred Stock [Member]
Supplemental Consolidating Statements Of Balance Sheets [Line Items]
Limited Partners' Capital			185,000
Subsidiaries [Member] | Series A Preferred Stock [Member] | Operating Partnership [Member]
Supplemental Consolidating Statements Of Balance Sheets [Line Items]
Limited Partners' Capital			185,000
Subsidiaries [Member] | Series A Preferred Stock [Member] | Subsidiary Guarantors [Member]
Supplemental Consolidating Statements Of Balance Sheets [Line Items]
Limited Partners' Capital			0
Subsidiaries [Member] | Series A Preferred Stock [Member] | Subsidiary Non-Guarantors [Member]
Supplemental Consolidating Statements Of Balance Sheets [Line Items]
Limited Partners' Capital			0
Subsidiaries [Member] | Series A Preferred Stock [Member] | Eliminations [Member]
Supplemental Consolidating Statements Of Balance Sheets [Line Items]
Limited Partners' Capital			0
Subsidiaries [Member] | Series B Preferred Stock [Member]
Supplemental Consolidating Statements Of Balance Sheets [Line Items]
Limited Partners' Capital			166,250
Subsidiaries [Member] | Series B Preferred Stock [Member] | Operating Partnership [Member]
Supplemental Consolidating Statements Of Balance Sheets [Line Items]
Limited Partners' Capital			166,250
Subsidiaries [Member] | Series B Preferred Stock [Member] | Subsidiary Guarantors [Member]
Supplemental Consolidating Statements Of Balance Sheets [Line Items]
Limited Partners' Capital			0
Subsidiaries [Member] | Series B Preferred Stock [Member] | Subsidiary Non-Guarantors [Member]
Supplemental Consolidating Statements Of Balance Sheets [Line Items]
Limited Partners' Capital			0
Subsidiaries [Member] | Series B Preferred Stock [Member] | Eliminations [Member]
Supplemental Consolidating Statements Of Balance Sheets [Line Items]
Limited Partners' Capital			0
Subsidiaries [Member] | Series C Preferred Stock [Member] | Operating Partnership [Member]
Supplemental Consolidating Statements Of Balance Sheets [Line Items]
Limited Partners' Capital	201,250
Subsidiaries [Member] | Series C Preferred Stock [Member] | Subsidiary Guarantors [Member]
Supplemental Consolidating Statements Of Balance Sheets [Line Items]
Limited Partners' Capital	0
Subsidiaries [Member] | Series C Preferred Stock [Member] | Subsidiary Non-Guarantors [Member]
Supplemental Consolidating Statements Of Balance Sheets [Line Items]
Limited Partners' Capital	0
Subsidiaries [Member] | Series C Preferred Stock [Member] | Eliminations [Member]
Supplemental Consolidating Statements Of Balance Sheets [Line Items]
Limited Partners' Capital	0
Subsidiaries [Member] | Limited partners' common units [Member]
Supplemental Consolidating Statements Of Balance Sheets [Line Items]
Limited Partners' Capital	754,892		594,927
Subsidiaries [Member] | Limited partners' common units [Member] | Operating Partnership [Member]
Supplemental Consolidating Statements Of Balance Sheets [Line Items]
Limited Partners' Capital	754,892		594,927
Subsidiaries [Member] | Limited partners' common units [Member] | Subsidiary Guarantors [Member]
Supplemental Consolidating Statements Of Balance Sheets [Line Items]
Limited Partners' Capital	1,960,881		2,086,367
Subsidiaries [Member] | Limited partners' common units [Member] | Subsidiary Non-Guarantors [Member]
Supplemental Consolidating Statements Of Balance Sheets [Line Items]
Limited Partners' Capital	752,215		460,098
Subsidiaries [Member] | Limited partners' common units [Member] | Eliminations [Member]
Supplemental Consolidating Statements Of Balance Sheets [Line Items]
Limited Partners' Capital	$ (2,713,096)		$ (2,546,465)
[1]	(1)Properties located in Ashburn, VA (ACC8, ACC9, ACC10, and ACC11), Elk Grove Village, IL (CH3), Santa Clara, CA (SC1 Phase III, formerly referred to as SC2), Hillsboro, OR (OR1 and OR2) and Vaughan, ON (TOR1).

18. Supplemental Consolidatin92

18. Supplemental Consolidating Financial Data for Subsidiary Guarantors of the Unsecured Notes Supplemental Consolidating Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues:
Base rent									$ 345,022	$ 298,585	$ 285,716
Recoveries from tenants									169,668	139,537	124,853
Other revenues									14,011	14,278	7,023
Total revenues	$ 141,688	$ 134,326	$ 128,538	$ 124,149	$ 115,923	$ 115,337	$ 113,826	$ 107,314	528,701	452,400	417,592
Expenses:
Property operating costs									154,064	130,051	117,339
Real estate taxes and insurance									20,180	21,335	14,195
Depreciation and amortization									107,781	104,044	96,780
General and administrative									23,043	18,064	17,181
Impairment of Long-Lived Assets to be Disposed of									0	122,472	0
Other expenses									11,781	16,859	9,222
Total expenses									316,849	412,825	254,717
Operating income									211,852	39,575	162,875
Interest:
Expense incurred									(48,294)	(40,510)	(33,583)
Amortization of deferred financing costs									(3,712)	(3,151)	(2,980)
Gain (Loss) on Disposition of Property Plant Equipment									22,833	0	0
Loss on early extinguishment of debt									(1,232)	0	(1,701)
Net (loss) income	$ 43,227	$ 40,966	$ 60,557	$ 36,697	$ (91,953)	$ 30,393	$ 31,141	$ 26,333	181,447	(4,086)	124,611
Preferred stock dividends									(20,739)	(27,245)	(27,245)
Other Preferred Stock Dividends and Adjustments									(12,495)	0	0
Subsidiaries [Member]
Revenues:
Base rent									345,022	298,585	285,716
Recoveries from tenants									169,668	139,537	124,853
Other revenues									14,011	14,278	7,023
Total revenues									528,701	452,400	417,592
Expenses:
Property operating costs									154,064	130,051	117,339
Real estate taxes and insurance									20,180	21,335	14,195
Depreciation and amortization									107,781	104,044	96,780
General and administrative									23,043	18,064	17,181
Impairment of Long-Lived Assets to be Disposed of									0	122,472	0
Other expenses									11,781	16,859	9,222
Total expenses									316,849	412,825	254,717
Operating income									211,852	39,575	162,875
Interest:
Expense incurred									(48,294)	(40,510)	(33,583)
Amortization of deferred financing costs									(3,712)	(3,151)	(2,980)
Gain (Loss) on Disposition of Property Plant Equipment									22,833	0	0
Loss on early extinguishment of debt									(1,232)	0	(1,701)
Equity in earnings									0	0	0
Net (loss) income									181,447	(4,086)	124,611
Preferred stock dividends									(20,739)	(27,245)	(27,245)
Other Preferred Stock Dividends and Adjustments									(12,495)	0	0
Net Income Loss Available To Common Unit holders Basic									148,213	(31,331)	97,366
Subsidiaries [Member] | Operating Partnership [Member]
Revenues:
Base rent									18,164	18,061	17,499
Recoveries from tenants									0	0	0
Other revenues									0	0	0
Total revenues									18,164	18,061	17,499
Expenses:
Property operating costs									0	0	0
Real estate taxes and insurance									0	0	0
Depreciation and amortization									100	43	63
General and administrative									22,009	17,574	16,159
Impairment of Long-Lived Assets to be Disposed of										0
Other expenses									1,564	6,151	3,508
Total expenses									23,673	23,768	19,730
Operating income									(5,509)	(5,707)	(2,231)
Interest:
Expense incurred									(56,318)	(50,021)	(41,107)
Amortization of deferred financing costs									(3,907)	(3,454)	(3,173)
Gain (Loss) on Disposition of Property Plant Equipment									21,643
Loss on early extinguishment of debt									(1,232)		(1,701)
Equity in earnings									226,770	55,096	172,823
Net (loss) income									181,447	(4,086)	124,611
Preferred stock dividends									(20,739)	(27,245)	(27,245)
Other Preferred Stock Dividends and Adjustments									(12,495)
Net Income Loss Available To Common Unit holders Basic									148,213	(31,331)	97,366
Subsidiaries [Member] | Subsidiary Guarantors [Member]
Revenues:
Base rent									270,357	268,433	267,454
Recoveries from tenants									142,863	127,877	115,185
Other revenues									1,668	1,787	1,657
Total revenues									414,888	398,097	384,296
Expenses:
Property operating costs									144,935	131,644	123,140
Real estate taxes and insurance									16,916	19,942	13,323
Depreciation and amortization									88,321	94,371	90,770
General and administrative									52	57	82
Impairment of Long-Lived Assets to be Disposed of										119,267
Other expenses									45	133	1,526
Total expenses									250,269	365,414	228,841
Operating income									164,619	32,683	155,455
Interest:
Expense incurred									1,270	1,327	4,323
Amortization of deferred financing costs									79	107	273
Gain (Loss) on Disposition of Property Plant Equipment									0
Loss on early extinguishment of debt									0		0
Equity in earnings									0	0	0
Net (loss) income									165,968	34,117	160,051
Preferred stock dividends									0	0	0
Other Preferred Stock Dividends and Adjustments									0
Net Income Loss Available To Common Unit holders Basic									165,968	34,117	160,051
Subsidiaries [Member] | Subsidiary Non-Guarantors [Member]
Revenues:
Base rent									74,727	30,302	18,413
Recoveries from tenants									26,805	11,660	9,668
Other revenues									12,388	12,621	5,489
Total revenues									113,920	54,583	33,570
Expenses:
Property operating costs									27,338	16,598	11,822
Real estate taxes and insurance									3,264	1,393	872
Depreciation and amortization									19,360	9,630	5,947
General and administrative									982	433	940
Impairment of Long-Lived Assets to be Disposed of										3,205
Other expenses									10,234	10,725	4,338
Total expenses									61,178	41,984	23,919
Operating income									52,742	12,599	9,651
Interest:
Expense incurred									6,754	8,184	3,201
Amortization of deferred financing costs									116	196	(80)
Gain (Loss) on Disposition of Property Plant Equipment									1,190
Loss on early extinguishment of debt									0		0
Equity in earnings									0	0	0
Net (loss) income									60,802	20,979	12,772
Preferred stock dividends									0	0	0
Other Preferred Stock Dividends and Adjustments									0
Net Income Loss Available To Common Unit holders Basic									60,802	20,979	12,772
Subsidiaries [Member] | Eliminations [Member]
Revenues:
Base rent									(18,226)	(18,211)	(17,650)
Recoveries from tenants									0	0	0
Other revenues									(45)	(130)	(123)
Total revenues									(18,271)	(18,341)	(17,773)
Expenses:
Property operating costs									(18,209)	(18,191)	(17,623)
Real estate taxes and insurance									0	0	0
Depreciation and amortization									0	0	0
General and administrative									0	0	0
Impairment of Long-Lived Assets to be Disposed of										0
Other expenses									(62)	(150)	(150)
Total expenses									(18,271)	(18,341)	(17,773)
Operating income									0	0	0
Interest:
Expense incurred									0	0	0
Amortization of deferred financing costs									0	0	0
Gain (Loss) on Disposition of Property Plant Equipment									0
Loss on early extinguishment of debt									0		0
Equity in earnings									(226,770)	(55,096)	(172,823)
Net (loss) income									(226,770)	(55,096)	(172,823)
Preferred stock dividends									0	0	0
Other Preferred Stock Dividends and Adjustments									0
Net Income Loss Available To Common Unit holders Basic									$ (226,770)	$ (55,096)	$ (172,823)

18. Supplemental Consolidatin93

18. Supplemental Consolidating Financial Data for Subsidiary Guarantors of the Unsecured Notes Supplemental Consodlidating Statements of Cash Flows (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Supplemental Consolidating Statements Of Cash Flows [Line Items]
Net Cash Provided by (Used in) Operating Activities		$ 289,962	$ 255,021	$ 244,513
Proceeds from Sale of Property, Plant, and Equipment		123,545	0	0
Investments in real estate – development		(294,764)	(217,339)	(265,374)
Payments to Acquire Real Estate		(53,105)	(8,600)	0
Payments to Acquire Land		20,168	0	0
Interest capitalized for real estate under development		10,380	11,564	(9,644)
Improvements to real estate		(4,843)	(3,459)	(1,916)
Additions to non-real estate property		(1,270)	(753)	(316)
Net cash used in investing activities		(260,985)	(241,715)	(277,250)
Proceeds from line of credit		135,899	120,000	60,000
Repayments		(85,000)	(180,000)	0
Repayments of Secured Debt		(3,750)	0	0
Proceeds		0	0	96,000
Proceeds		0	248,012	0
Payments of financing costs		(5,866)	(4,740)	(3,829)
Proceeds from Issuance of Common Stock		275,470	0	0
Proceeds from Issuance of Redeemable Preferred Stock		194,252	0	0
Payments for Repurchase of Redeemable Preferred Stock		(351,250)	0	0
Equity compensation (payments) proceeds		7,623	249	4,363
Common stock repurchases		0	(31,912)	0
Net Cash Provided by (Used in) Financing Activities		(21,583)	(11,674)	23,602
Cash and Cash Equivalents, Period Increase (Decrease)		7,394	1,632	(9,135)
Cash and cash equivalents, ending		38,624	31,230	29,598
Subsidiaries [Member]
Supplemental Consolidating Statements Of Cash Flows [Line Items]
Net cash (used in) provided by operating activities before return on investment in subsidiaries		289,962
Return on investment in subsidiaries		0
Net Cash Provided by (Used in) Operating Activities		289,962	255,024	244,514
Proceeds from Sale of Property, Plant, and Equipment		123,545	0	0
Investments in real estate – development		(294,764)	(217,339)	(265,374)
Payments to Acquire Real Estate		(53,105)	(8,600)	0
Payments to Acquire Land		20,168	0	0
Investments in affiliates		0	0	0
Proceeds from Divestiture of Interest in Consolidated Subsidiaries		0
Interest capitalized for real estate under development		(10,380)	(11,564)	(9,644)
Improvements to real estate		(4,843)	(3,459)	(1,916)
Additions to non-real estate property		(1,270)	(753)	(316)
Net cash used in investing activities		(260,985)	(241,715)	(277,250)
Proceeds from line of credit		135,899	120,000	60,000
Repayments		(85,000)	(180,000)	0
Repayments of Secured Debt		(3,750)	0	0
Proceeds		0	0	96,000
Proceeds		0	248,012	0
Payments of financing costs		(5,866)	(4,740)	(3,829)
Proceeds from Issuance of Common Stock		275,470	0	0
Proceeds from Issuance of Redeemable Preferred Stock		194,252	0	0
Payments for Repurchase of Redeemable Preferred Stock		(351,250)	0	0
Equity compensation (payments) proceeds		7,623	249	4,363
Proceeds from Contributions from Parent		0
Distribution to parent		0
Common stock repurchases	$ (31,912)	0	(31,912)	0
Distributions		(188,961)	(163,283)	(132,932)
Net Cash Provided by (Used in) Financing Activities		(21,583)	(11,674)	23,602
Cash and Cash Equivalents, Period Increase (Decrease)		7,394	1,635	(9,134)
Cash and cash equivalents, ending		34,409	27,015	25,380
Subsidiaries [Member] | Operating Partnership [Member]
Supplemental Consolidating Statements Of Cash Flows [Line Items]
Net cash (used in) provided by operating activities before return on investment in subsidiaries		(60,010)
Return on investment in subsidiaries		349,972
Net Cash Provided by (Used in) Operating Activities		289,962	(55,999)	(40,234)
Proceeds from Sale of Property, Plant, and Equipment		0
Investments in real estate – development		0	(415)	(404)
Payments to Acquire Real Estate		0	0
Payments to Acquire Land		0
Investments in affiliates		(384,605)	68,074	5,654
Proceeds from Divestiture of Interest in Consolidated Subsidiaries		123,545
Interest capitalized for real estate under development		(2)	(27)	(10)
Improvements to real estate		0	0	0
Additions to non-real estate property		(1,008)	(93)	(20)
Net cash used in investing activities		(262,070)	67,539	5,220
Proceeds from line of credit		135,899	120,000	60,000
Repayments		(85,000)	(180,000)
Repayments of Secured Debt		0
Proceeds				96,000
Proceeds			248,012
Payments of financing costs		(5,841)	(4,715)	(3,514)
Proceeds from Issuance of Common Stock		275,470
Proceeds from Issuance of Redeemable Preferred Stock		194,252
Payments for Repurchase of Redeemable Preferred Stock		(351,250)
Equity compensation (payments) proceeds		7,623	249	4,363
Proceeds from Contributions from Parent		0
Distribution to parent		0
Common stock repurchases			(31,912)
Distributions		(188,961)	(163,283)	(132,932)
Net Cash Provided by (Used in) Financing Activities		(17,808)	(11,649)	23,917
Cash and Cash Equivalents, Period Increase (Decrease)		10,084	(109)	(11,097)
Cash and cash equivalents, ending		31,781	21,697	21,806
Subsidiaries [Member] | Subsidiary Guarantors [Member]
Supplemental Consolidating Statements Of Cash Flows [Line Items]
Net cash (used in) provided by operating activities before return on investment in subsidiaries		265,244
Return on investment in subsidiaries		0
Net Cash Provided by (Used in) Operating Activities		265,244	278,557	264,409
Proceeds from Sale of Property, Plant, and Equipment		120,086
Investments in real estate – development		(62,343)	(8,996)	(111,791)
Payments to Acquire Real Estate		0	0
Payments to Acquire Land		0
Investments in affiliates		0	(264,211)	(146,188)
Proceeds from Divestiture of Interest in Consolidated Subsidiaries		0
Interest capitalized for real estate under development		(1,269)	(1,327)	(4,323)
Improvements to real estate		(4,739)	(3,401)	(1,850)
Additions to non-real estate property		(220)	(622)	(257)
Net cash used in investing activities		51,515	(278,557)	(264,409)
Proceeds from line of credit		0	0	0
Repayments		0	0
Repayments of Secured Debt		0
Proceeds				0
Proceeds			0
Payments of financing costs		0	0	0
Proceeds from Issuance of Common Stock		0
Proceeds from Issuance of Redeemable Preferred Stock		0
Payments for Repurchase of Redeemable Preferred Stock		0
Equity compensation (payments) proceeds		0	0	0
Proceeds from Contributions from Parent		68,571
Distribution to parent		(385,330)
Common stock repurchases	0
Distributions		0	0	0
Net Cash Provided by (Used in) Financing Activities		(316,759)	0	0
Cash and Cash Equivalents, Period Increase (Decrease)		0	0	0
Cash and cash equivalents, ending		0	0	0
Subsidiaries [Member] | Subsidiary Non-Guarantors [Member]
Supplemental Consolidating Statements Of Cash Flows [Line Items]
Net cash (used in) provided by operating activities before return on investment in subsidiaries		84,728
Return on investment in subsidiaries		0
Net Cash Provided by (Used in) Operating Activities		84,728	32,466	20,339
Proceeds from Sale of Property, Plant, and Equipment		3,459
Investments in real estate – development		(232,421)	(207,928)	(153,179)
Payments to Acquire Real Estate		(53,105)	(8,600)
Payments to Acquire Land		20,168
Investments in affiliates		0	196,137	140,534
Proceeds from Divestiture of Interest in Consolidated Subsidiaries		0
Interest capitalized for real estate under development		(9,109)	(10,210)	(5,311)
Improvements to real estate		(104)	(58)	(66)
Additions to non-real estate property		(42)	(38)	(39)
Net cash used in investing activities		(311,490)	(30,697)	(18,061)
Proceeds from line of credit		0	0	0
Repayments		0	0
Repayments of Secured Debt		(3,750)
Proceeds				0
Proceeds			0
Payments of financing costs		(25)	(25)	(315)
Proceeds from Issuance of Common Stock		0
Proceeds from Issuance of Redeemable Preferred Stock		0
Payments for Repurchase of Redeemable Preferred Stock		0
Equity compensation (payments) proceeds		0	0	0
Proceeds from Contributions from Parent		316,034
Distribution to parent		(88,187)
Common stock repurchases	0
Distributions		0	0	0
Net Cash Provided by (Used in) Financing Activities		224,072	(25)	(315)
Cash and Cash Equivalents, Period Increase (Decrease)		(2,690)	1,744	1,963
Cash and cash equivalents, ending		2,628	5,318	3,574
Subsidiaries [Member] | Eliminations [Member]
Supplemental Consolidating Statements Of Cash Flows [Line Items]
Net cash (used in) provided by operating activities before return on investment in subsidiaries		0
Return on investment in subsidiaries		(349,972)
Net Cash Provided by (Used in) Operating Activities		(349,972)	0	0
Proceeds from Sale of Property, Plant, and Equipment		0
Investments in real estate – development		0	0	0
Payments to Acquire Real Estate		0	0
Payments to Acquire Land		0
Investments in affiliates		384,605	0	0
Proceeds from Divestiture of Interest in Consolidated Subsidiaries		(123,545)
Interest capitalized for real estate under development		0	0	0
Improvements to real estate		0	0	0
Additions to non-real estate property		0	0	0
Net cash used in investing activities		261,060	0	0
Proceeds from line of credit		0	0	0
Repayments		0	0
Repayments of Secured Debt		0
Proceeds				0
Proceeds			0
Payments of financing costs		0	0	0
Proceeds from Issuance of Common Stock		0
Proceeds from Issuance of Redeemable Preferred Stock		0
Payments for Repurchase of Redeemable Preferred Stock		0
Equity compensation (payments) proceeds		0	0	0
Proceeds from Contributions from Parent		(384,605)
Distribution to parent		473,517
Common stock repurchases	$ 0
Distributions		0	0	0
Net Cash Provided by (Used in) Financing Activities		88,912	0	0
Cash and Cash Equivalents, Period Increase (Decrease)		0	0	0
Cash and cash equivalents, ending		$ 0	$ 0	$ 0

19. Subsequent Events (Details)

19. Subsequent Events (Details) $ in Millions	2 Months Ended	3 Months Ended	12 Months Ended
	Feb. 23, 2017shares	Mar. 31, 2017USD ($)a	Dec. 31, 2016shares	Dec. 31, 2015shares	Dec. 31, 2014shares
Subsequent Event [Line Items]
Land purchase agreement Mesa, Arizona - acres | a		56.5
Land purchase agreement Mesa, Arizona - purchase price | $		$ 12.2
Redemption of operating partnership units, shares | shares	1,409,147		1,618,048	363,674	234,300

Schedule II - Consolidated Al95

Schedule II - Consolidated Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Valuation and Qualifying Accounts Disclosure [Line Items]
Notes Receivable, Gross	$ 25,000	$ 6,500
Allowance for doubtful accounts, Balance at Beginning of Period	5,241	8,520	$ 3,700
Charges to operations	(108)	372	4,829
Other Additions	18,486	0	0
Net recovery (Deductions)	0	(3,651)	(9)
Allowance for doubtful accounts, Balance at End of Period	$ 23,619	$ 5,241	$ 8,520

Schedule III - Consolidated R96

Schedule III - Consolidated Real Estate and Accumulated Depreciation Real Estate and Accumulated Depreciation (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances		$ 111,250
Real Estate and Accumulated Depreciation, Initial Cost of Land		197,749
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements		3,216,320
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements		41,165
Real Estate and Accumulated Depreciation, Carrying Amount of Land		197,749
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements		3,257,485
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements		3,455,234	$ 3,132,078	$ 3,066,297	$ 2,799,010
Real Estate and Accumulated Depreciation, Accumulated Depreciation		662,183	$ 560,837	$ 504,869	$ 413,394
Real Estate, Federal Income Tax Basis		2,780,000
ACC2 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	[1]	0
Real Estate and Accumulated Depreciation, Initial Cost of Land	[1]	2,500
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	[1]	157,100
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	[1]	(620)
Real Estate and Accumulated Depreciation, Carrying Amount of Land	[1]	2,500
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	[1]	156,480
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	[1]	158,980
Real Estate and Accumulated Depreciation, Accumulated Depreciation	[1]	$ 57,184
Real Estate and Accumulated Depreciation, Year of Construction		2,005
Real Estate And Accumulated Depreciation, Year Acquired		2,001
ACC3 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	[2]	$ 111,250
Real Estate and Accumulated Depreciation, Initial Cost of Land	[2]	1,071
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	[2]	92,631
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	[2]	3,449
Real Estate and Accumulated Depreciation, Carrying Amount of Land	[2]	1,071
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	[2]	96,080
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	[2]	97,151
Real Estate and Accumulated Depreciation, Accumulated Depreciation	[2]	$ 36,136
Real Estate and Accumulated Depreciation, Year of Construction		2,006
Real Estate And Accumulated Depreciation, Year Acquired		2,001
ACC4 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	[1]	$ 0
Real Estate and Accumulated Depreciation, Initial Cost of Land	[1]	6,600
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	[1]	535,526
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	[1]	3,343
Real Estate and Accumulated Depreciation, Carrying Amount of Land	[1]	6,600
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	[1]	538,869
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	[1]	545,469
Real Estate and Accumulated Depreciation, Accumulated Depreciation	[1]	$ 176,477
Real Estate and Accumulated Depreciation, Year of Construction		2,007
Real Estate And Accumulated Depreciation, Year Acquired		2,006
ACC5 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	[1]	$ 0
Real Estate and Accumulated Depreciation, Initial Cost of Land	[1]	6,443
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	[1]	292,369
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	[1]	6,647
Real Estate and Accumulated Depreciation, Carrying Amount of Land	[1]	6,443
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	[1]	299,016
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	[1]	305,459
Real Estate and Accumulated Depreciation, Accumulated Depreciation	[1]	$ 71,347
Real Estate And Accumulated Depreciation, Year Acquired		2,007
ACC6 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	[1]	$ 0
Real Estate and Accumulated Depreciation, Initial Cost of Land	[1]	5,518
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	[1]	215,235
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	[1]	1,594
Real Estate and Accumulated Depreciation, Carrying Amount of Land	[1]	5,518
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	[1]	216,829
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	[1]	222,347
Real Estate and Accumulated Depreciation, Accumulated Depreciation	[1]	$ 35,197
Real Estate And Accumulated Depreciation, Year Acquired		2,007
ACC7 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	[1]	$ 0
Real Estate and Accumulated Depreciation, Initial Cost of Land	[1]	9,753
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements		328,520
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	[1]	4,450
Real Estate and Accumulated Depreciation, Carrying Amount of Land	[1]	9,753
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	[1]	332,970
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	[1]	342,723
Real Estate and Accumulated Depreciation, Accumulated Depreciation	[1]	$ 13,320
Real Estate And Accumulated Depreciation, Year Acquired		2,011
CH1 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	[1]	$ 0
Real Estate and Accumulated Depreciation, Initial Cost of Land	[1]	23,611
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	[1]	357,194
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	[1]	1,977
Real Estate and Accumulated Depreciation, Carrying Amount of Land	[1]	23,611
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	[1]	359,171
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	[1]	382,782
Real Estate and Accumulated Depreciation, Accumulated Depreciation	[1]	$ 82,947
Real Estate And Accumulated Depreciation, Year Acquired		2,007
CH2 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances		$ 0
Real Estate and Accumulated Depreciation, Initial Cost of Land	[1]	14,392
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	[1]	255,593
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	[1]	946
Real Estate and Accumulated Depreciation, Carrying Amount of Land	[1]	14,392
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	[1]	256,539
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	[1]	270,931
Real Estate and Accumulated Depreciation, Accumulated Depreciation	[1]	$ 7,239
Real Estate And Accumulated Depreciation, Year Acquired		2,013
SC1 Phase I and II [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	[1]	$ 0
Real Estate and Accumulated Depreciation, Initial Cost of Land	[1]	20,202
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	[1]	429,572
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	[1]	3,527
Real Estate and Accumulated Depreciation, Carrying Amount of Land	[1]	20,202
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	[1]	433,099
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	[1]	453,301
Real Estate and Accumulated Depreciation, Accumulated Depreciation	[1]	$ 53,697
Real Estate And Accumulated Depreciation, Year Acquired		2,007
VA3 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	[1]	$ 0
Real Estate and Accumulated Depreciation, Initial Cost of Land	[1]	9,000
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	[1]	172,881
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	[1]	6,813
Real Estate and Accumulated Depreciation, Carrying Amount of Land	[1]	9,000
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	[1]	179,694
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	[1]	188,694
Real Estate and Accumulated Depreciation, Accumulated Depreciation	[1]	$ 72,725
Real Estate and Accumulated Depreciation, Year of Construction		2,003
Real Estate And Accumulated Depreciation, Year Acquired		2,003
VA4 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	[1]	$ 0
Real Estate and Accumulated Depreciation, Initial Cost of Land	[1]	6,800
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	[1]	140,575
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	[1]	9,039
Real Estate and Accumulated Depreciation, Carrying Amount of Land	[1]	6,800
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements	[1]	149,614
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements	[1]	156,414
Real Estate and Accumulated Depreciation, Accumulated Depreciation	[1]	$ 55,914
Real Estate and Accumulated Depreciation, Year of Construction		2,005
Real Estate And Accumulated Depreciation, Year Acquired		2,005
Operating Properties [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances		$ 111,250
Real Estate and Accumulated Depreciation, Initial Cost of Land		105,890
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements		2,977,196
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements		41,165
Real Estate and Accumulated Depreciation, Carrying Amount of Land		105,890
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements		3,018,361
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements		3,124,251
Real Estate and Accumulated Depreciation, Accumulated Depreciation		662,183
ACC8 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
Real Estate and Accumulated Depreciation, Initial Cost of Land		3,786
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements		466
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements		0
Real Estate and Accumulated Depreciation, Carrying Amount of Land		3,786
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements		466
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements		4,252
Real Estate and Accumulated Depreciation, Accumulated Depreciation		$ 0
Real Estate And Accumulated Depreciation, Year Acquired		2,007
ACC9 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances		$ 0
Real Estate and Accumulated Depreciation, Initial Cost of Land		8,469
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements		138,561
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements		0
Real Estate and Accumulated Depreciation, Carrying Amount of Land		8,469
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements		138,561
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements		147,030
Real Estate and Accumulated Depreciation, Accumulated Depreciation		$ 0
Real Estate And Accumulated Depreciation, Year Acquired		2,016
ACC10 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances		$ 0
Real Estate and Accumulated Depreciation, Initial Cost of Land		7,343
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements		1,872
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements		0
Real Estate and Accumulated Depreciation, Carrying Amount of Land		7,343
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements		1,872
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements		9,215
Real Estate and Accumulated Depreciation, Accumulated Depreciation		$ 0
Real Estate And Accumulated Depreciation, Year Acquired		2,016
ACC11 or Powered-base shell [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances		$ 0
Real Estate and Accumulated Depreciation, Initial Cost of Land		4,773
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements		6
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements		0
Real Estate and Accumulated Depreciation, Carrying Amount of Land		4,773
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements		6
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements		4,779
Real Estate and Accumulated Depreciation, Accumulated Depreciation		$ 0
Real Estate And Accumulated Depreciation, Year Acquired		2,016
CH3 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances		$ 0
Real Estate and Accumulated Depreciation, Initial Cost of Land		8,578
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements		8,740
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements		0
Real Estate and Accumulated Depreciation, Carrying Amount of Land		8,578
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements		8,740
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements		17,318
Real Estate and Accumulated Depreciation, Accumulated Depreciation		$ 0
Real Estate And Accumulated Depreciation, Year Acquired		2,015
OR1 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances		$ 0
Real Estate and Accumulated Depreciation, Initial Cost of Land		5,775
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements		1,328
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements		0
Real Estate and Accumulated Depreciation, Carrying Amount of Land		5,775
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements		1,328
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements		7,103
Real Estate and Accumulated Depreciation, Accumulated Depreciation		$ 0
Real Estate And Accumulated Depreciation, Year Acquired		2,016
OR2 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances		$ 0
Real Estate and Accumulated Depreciation, Initial Cost of Land		5,775
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements		301
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements		0
Real Estate and Accumulated Depreciation, Carrying Amount of Land		5,775
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements		301
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements		6,076
Real Estate and Accumulated Depreciation, Accumulated Depreciation		$ 0
Real Estate And Accumulated Depreciation, Year Acquired		2,016
TOR1 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances		$ 0
Real Estate and Accumulated Depreciation, Initial Cost of Land		42,128
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements		4,246
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements		0
Real Estate and Accumulated Depreciation, Carrying Amount of Land		42,128
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements		4,246
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements		46,374
Real Estate and Accumulated Depreciation, Accumulated Depreciation		$ 0
Real Estate And Accumulated Depreciation, Year Acquired		2,016
SC1 Phase III [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances	[1]	$ 0
Real Estate and Accumulated Depreciation, Initial Cost of Land		5,232
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements	[1]	83,604
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements	[1]	0
Real Estate and Accumulated Depreciation, Carrying Amount of Land		5,232
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements		83,604
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements		88,836
Real Estate and Accumulated Depreciation, Accumulated Depreciation		$ 0
Real Estate And Accumulated Depreciation, Year Acquired		2,007
Development Properties [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Amount of Encumbrances		$ 0
Real Estate and Accumulated Depreciation, Initial Cost of Land		91,859
Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements		239,124
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements		0
Real Estate and Accumulated Depreciation, Carrying Amount of Land		91,859
Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements		239,124
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements		330,983
Real Estate and Accumulated Depreciation, Accumulated Depreciation		$ 0
Minimum [Member] | ACC5 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Year of Construction	[1]	2,009
Minimum [Member] | ACC6 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Year of Construction	[1]	2,011
Minimum [Member] | ACC7 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Year of Construction	[1]	2,014
Minimum [Member] | CH1 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Year of Construction	[1]	2,008
Minimum [Member] | CH2 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Year of Construction	[1]	2,015
Minimum [Member] | SC1 Phase I and II [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Year of Construction	[1]	2,011
Maximum [Member] | ACC5 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Year of Construction	[1]	2,010
Maximum [Member] | ACC6 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Year of Construction	[1]	2,013
Maximum [Member] | ACC7 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Year of Construction	[1]	2,016
Maximum [Member] | CH1 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Year of Construction	[1]	2,012
Maximum [Member] | CH2 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Year of Construction	[1]	2,016
Maximum [Member] | SC1 Phase I and II [Member]
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Year of Construction	[1]	2,015
[1]	(1) The subsidiaries that own these data centers and development properties are guarantors of the Unsecured Notes due 2021 and 2023, the Unsecured Credit Facility and the Unsecured Term Loan.
[2]	(2) The subsidiary that owns this data center is encumbered by our ACC3 Term Loan.

Schedule III - Consolidated R97

Schedule III - Consolidated Real Estate and Accumulated Depreciation Reconciliation of Real Estate Assets and Accumulated Depreciation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
SEC Schedule III, Real Estate and Accumulated Depreciation Disclosure [Abstract]
Real estate assets Balance, beginning of period	$ 3,132,078	$ 3,066,297	$ 2,799,010
Additions - property acquisitions	73,273	8,600	0
Additions - improvements	344,960	221,588	267,357
Deductions - write offs	(95,077)	(164,407)	70
Real estate assets Balance, end of period	3,455,234	3,132,078	3,066,297
Accumulated depreciation Balance, beginning of period	560,837	504,869	413,394
Additions - depreciation	102,614	97,988	91,545
Deductions - write offs	(1,268)	(42,020)	70
Accumulated depreciation Balance, end of period	$ 662,183	$ 560,837	$ 504,869