11. Earnings Per Unit of the Operating Partnership (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
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)	80,321,840	81,826,688	80,626,882	81,724,511
Effect of dilutive securities	0	887,163	853,658	906,152
Weighted average common units – diluted	80,321,840	82,713,851	81,480,540	82,630,663
Restricted Units	300,000	0	0
Stock Options excluded from diluted earnings per share or unit	2,400,000	900,000	1,200,000	900,000
Performance Units excluded from diluted earnings per share or unit	100,000	100,000	100,000	100,000
DuPont Fabros Technology, L.P. [Member]
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)	80,321,840	82,713,851	81,480,540	82,630,663