Dispositions (Results of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	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, 2015	Dec. 31, 2014	Dec. 31, 2013
Expenses:
Discontinued operations	$ (2,331)	$ (22,383)	$ 18,243	$ 17,574	$ 20,709	$ 18,171	$ 30,781	$ 30,074	$ 11,103	$ 99,735	$ 79,171
CCP | Spinoff
Revenues:
Rental income									196,848	295,767	291,524
Resident fees and services									2,148	3,392	3,783
Interest and other income									63	2	25
Total Revenues									199,059	299,161	295,332
Expenses:
Interest									61,613	87,648	89,602
Depreciation and amortization									79,479	101,760	94,606
General, administrative and professional fees									9	9	25
Merger-related expenses and deal costs									46,402	1,746	0
Other									1,332	13,184	1,368
Total expenses									188,835	204,347	185,601
Income (loss) before income taxes and gain on real estate dispositions									10,224	94,814	109,731
Gain on real estate dispositions									0	0	0
Discontinued operations									10,224	94,814	109,731
Net income attributable to noncontrolling interest									120	185	220
Net income from discontinued operations attributable to common stockholders									$ 10,104	$ 94,629	$ 109,511