Significant Tenant (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Operations
Total revenues	$ 158,633	$ 113,700	$ 450,678	$ 313,414
Operating income	62,297	54,511	184,325	162,152
Net income (loss)	25,646	29,996	91,248	112,819
Cash Flows
Cash provided by operating activities			239,012	167,843
Change in cash and cash equivalents			(2,575)	15,979
Cash and cash equivalents at beginning of period			23,560	10,866
Cash and cash equivalents at end of period	20,985	26,845	20,985	26,845
Rents from significant lessee | Five Star
Operations
Total revenues	332,420	310,561	991,781	891,152
Operating income	5,316	4,080	15,317	17,948
Income from continuing operations	3,405	3,546	9,935	14,750
Net income (loss)	16,439	(528)	21,446	8,800
Cash Flows
Cash provided by operating activities			43,235	45,957
Net cash (used in) provided by discontinued operations			(8,317)	652
Cash provided by (used in) investing activities			1,912	(126,463)
Cash (used in) provided by financing activities			(50,909)	101,030
Change in cash and cash equivalents			(14,079)	21,176
Cash and cash equivalents at beginning of period			28,374	20,770
Cash and cash equivalents at end of period	14,295	41,946	14,295	41,946
Financial Position
Current assets	128,465	154,185	128,465	154,185
Non-current assets	435,041	394,894	435,041	394,894
Total indebtedness	71,431	132,995	71,431	132,995
Current liabilities	157,904	208,195	157,904	208,195
Non-current liabilities	102,875	113,116	102,875	113,116
Total shareholders' equity	$ 302,727	$ 227,768	$ 302,727	$ 227,768