CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Rental income:
Triple-net leased	$ 845,834	$ 779,801	$ 674,547
Office	630,342	566,245	463,910
Total rental income	1,476,176	1,346,046	1,138,457
Resident fees and services	1,847,306	1,811,255	1,552,951
Office building and other services revenue	21,070	41,492	29,364
Income from loans and investments	98,094	86,553	51,778
Interest and other income	876	1,052	4,263
Total revenues	3,443,522	3,286,398	2,776,813
Expenses
Interest	419,740	367,114	292,065
Depreciation and amortization	898,924	894,057	725,216
Property-level operating expenses:
Senior living	1,242,978	1,209,415	1,036,556
Office	191,784	174,225	158,832
Total property-level operating expenses	1,434,762	1,383,640	1,195,388
Office building services costs	7,311	26,565	17,092
General, administrative and professional fees	126,875	128,035	121,738
Loss on extinguishment of debt, net	2,779	14,411	5,564
Merger-related expenses and deal costs	24,635	102,944	43,304
Other	9,988	17,957	25,743
Total expenses	2,925,014	2,934,723	2,426,110
Income before unconsolidated entities, income taxes, discontinued operations, real estate dispositions and noncontrolling interest	518,508	351,675	350,703
Income (loss) from unconsolidated entities	4,358	(1,420)	(139)
Income tax benefit	31,343	39,284	8,732
Income from continuing operations	554,209	389,539	359,296
Discontinued operations	(922)	11,103	99,735
Gain on real estate dispositions	98,203	18,580	17,970
Net income	651,490	419,222	477,001
Net income attributable to noncontrolling interest	2,259	1,379	1,234
Net income attributable to common stockholders	$ 649,231	$ 417,843	$ 475,767
Basic:
Income from continuing operations attributable to common stockholders, including real estate dispositions (USD per share)	$ 1.88	$ 1.23	$ 1.28
Discontinued operations (USD per share)	0.00	0.03	0.34
Net income attributable to common stockholders (USD per share)	1.88	1.26	1.62
Diluted:
Income from continuing operations attributable to common stockholders, including real estate dispositions (USD per share)	1.86	1.22	1.26
Discontinued operations (USD per share)	0.00	0.03	0.34
Net income attributable to common stockholders (USD per share)	$ 1.86	$ 1.25	$ 1.60
Weighted average shares used in computing earnings per common share:
Basic (in shares)	344,703	330,311	294,175
Diluted (in shares)	348,390	334,007	296,677