Income Taxes (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Current:
State	$ 375	$ 312	$ 300
Total	375	312	300
Income tax provision	375	312	300
Reconciliation of effective tax rate and the U.S. federal statutory income tax rate
Taxes at statutory U.S. federal income tax rate (as a percent)	35.00%	35.00%	35.00%
Nontaxable income of SNH (as a percent)	(35.00%)	(35.00%)	(35.00%)
State and local income taxes, net of federal tax benefit (as a percent)	0.30%	0.20%	0.30%
Change in valuation allowance (as a percent)	2.40%	0.40%
Other differences, net (as a percent)	(2.40%)	(0.40%)
Effective tax rate (as a percent)	0.30%	0.20%	0.30%
Deferred tax assets:
Deferred revenue	2,169	489
Tax loss carry forwards	1,751	241
Deferred tax assets, gross	3,920	730
Valuation allowance	(3,814)	(617)
Deferred tax assets, net	106	113
Deferred tax liabilities:
Depreciable assets	(106)	(113)
Percentage of valuation allowance provided	100.00%	100.00%
Net operating loss carry forwards for federal income tax purposes	$ 4,502