American Realty Capital Trust, Inc. (ARCT) (Details) (USD $)	3 Months Ended		0 Months Ended	2 Months Ended	3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Jan. 22, 2013 Tau Operating Partnership, L.P. item	Mar. 31, 2013 Tau Operating Partnership, L.P.	Mar. 31, 2013 ARCT item	Jan. 22, 2013 ARCT item	Dec. 31, 2012 ARCT
Acquisition of American Realty Capital Trust, Inc.
Transaction value						$ 3,200,000,000
Cash paid for common stock on acquisition (in dollars per share)						$ 0.35
Common stock conversion ratio						0.2874
Repayment of amount outstanding under ARCT's revolving credit facility and term loan						552,900,000
Number of properties added to portfolio						515
Preliminary purchase price of the ARCT acquisition
Consideration associated with equity issued						2,027,753,000
Cash consideration paid to previous owners of ARCT						56,216,000
Total preliminary purchase consideration						2,083,969,000
Assets:
Real estate					2,621,747,000	2,621,747,000
Acquired lease intangible assets						611,650,000
Cash and cash equivalents, accounts receivable, and other assets, net					21,100,000	42,570,000
Total Assets						3,275,967,000
Liabilities:
Lines of credit payable					317,207,000	317,207,000
Term loan					235,000,000	235,000,000
Mortgage notes payable					539,000,000	538,960,000
Acquired lease intangible liabilities					76,000,000	76,041,000
Accounts payable, accrued expenses, and other liabilities, net					24,790,000	24,790,000
Total Liabilities						1,191,998,000
Estimated fair value of net assets acquired						2,083,969,000
Transaction Costs
Estimated total merger-related transaction costs					20,000,000
Total merger-related transaction costs					12,000,000		7,900,000
Number of properties			515		515
Ownership interest represented by the partnership units issued						0.7058%
Partnership units, ownership interest (as a percent)						99.2942%
Conversion ratio	1
Payment rate per annum (as a percent)			2.00%
Carrying value of preferred units	6,750,000			6,750,000
Change in the carrying value of common units classified as noncontrolling interest
Fair value of units issued at beginning of the period				13,962,000
Distributions	115,000			(173,000)
Allocation of net income	(9,000)			9,000
Carrying value at end of the period	$ 13,798,000		$ 13,962,000	$ 13,798,000
Common stock issued to shareholders	196,226,594	133,452,411				45,573,144
Closing price of common stock (in dollars per share)						$ 44.04