Compensation Plans - Others (Details) $ / shares in Units, $ in Millions			12 Months Ended
	Feb. 02, 2015 USD ($) $ / shares shares	Feb. 03, 2014 USD ($) $ / shares shares	Dec. 31, 2015 USD ($) item $ / shares shares	Dec. 31, 2014 USD ($) $ / shares shares	Dec. 31, 2013 USD ($) $ / shares shares
Termination
Deferred compensation cost | $			$ 19.0
Employee Benefit Plan
Matching contribution by Company, maximum percentage of participant's eligible compensation (as a percentage)			4.00%
Matching contributions to Employee Benefit Plan | $			$ 1.0	$ 1.0	$ 1.0
Common Stock Options
Shares Authorized under Stock Option Plan Exercise Price Range
Shares under Options (in shares) | shares			1,738,000
Weighted Average Exercise Price (in dollars per share)			$ 38.58
Currently Exercisable - Shares Under Options (in shares) | shares			1,368,000
Currently Exercisable - Weighted Average Exercise Price (in dollars per share)			$ 37.88
Share-based Compensation Arrangement by Share-based Payment Award, Options Unvested
Unvested at the beginning of the period (in shares) | shares			906,000
Vested (in shares) | shares			(512,000)
Forfeited (in shares) | shares			(24,000)
Unvested at the end of the period (in shares) | shares			370,000	906,000
Unvested at the beginning of the period, weighted average grant date fair value (in dollars per share)			$ 4.85
Vested, weighted average grant date fair value (in dollars per share)			5.06
Forfeited, weighted average grant date fair value (in dollars per share)			4.58
Unvested at the end of the period, weighted average grant date fair value (in dollars per share)			$ 4.59	$ 4.85
Share-based Compensation Arrangement by Share-based Payment Award, Options, Other Information
Granted (in shares) | shares			0
Granted, weighted average grant date fair value (in dollars per share)				$ 3.80	$ 5.89
Total vesting date intrinsic values (at vesting) of shares under options vested | $			$ 1.0	$ 7.0	$ 12.0
Total intrinsic value of vested shares under options at the end of the period | $			5.0
Proceeds received from options exercised | $			28.0	5.0	18.0
Total intrinsic value (at exercise) of options exercised | $			$ 10.0	$ 3.0	$ 25.0
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology
Implied volatility traded option on common stock period			30 days
Risk-free rate (as a percent)				1.34%	0.78%
Expected life (in years)				4 years 6 months	4 years 6 months
Expected volatility (as a percent)				22.90%	28.90%
Expected dividend yield (as a percent)				5.40%	5.80%
Restricted Stock and Performance Restricted Stock Units
Stock-based awards, vesting period			10 years
Restricted Stock and Performance Restricted Stock Units
Restricted Stock and Performance Restricted Stock Units
Performance restricted stock unit is convertible into common stock (in shares) | item			1
Shares withheld to offset tax withholding obligations (in shares) | shares			200,000	323,000	242,000
Unvested restricted stock and performance restricted stock units activity
Weighted-average remaining vesting period of restricted stock and restricted stock units			1 year
Total fair values (at vesting) of restricted stock and restricted stock units vested | $			$ 21.0	$ 24.0	$ 22.0
Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology
Risk-free rate (as a percent)			0.33%	0.22%
Expected volatility (as a percent)			17.94%	21.74%
Expected dividend yield (as a percent)			4.79%	5.61%
Unvested restricted stock and performance restricted stock units activity
Unvested at the beginning of the period (in shares) | shares			112,000
Vested (in shares) | shares			(76,000)
Unvested at the end of the period (in shares) | shares			36,000	112,000
Unvested at the beginning of the period, Weighted Average Grant Date Fair Value (in dollars per share)			$ 38.69
Vested, Weighted Average Grant Date Fair Value (in dollars per share)			37.26
Unvested at the end of the period, Weighted Average Grant Date Fair Value (in dollars per share)			$ 41.77	$ 38.69
Restricted Stock Units
Unvested restricted stock and performance restricted stock units activity
Unvested at the beginning of the period (in shares) | shares			900,000
Granted (in shares) | shares			402,000
Vested (in shares) | shares			(409,000)
Forfeited (in shares) | shares			(26,000)
Unvested at the end of the period (in shares) | shares			867,000	900,000
Unvested at the beginning of the period, Weighted Average Grant Date Fair Value (in dollars per share)			$ 40.54
Granted, Weighted Average Grant Date Fair Value (in dollars per share)			48.56
Vested, Weighted Average Grant Date Fair Value (in dollars per share)			44.79
Forfeited, Weighted Average Grant Date Fair Value (in dollars per share)			43.74
Unvested at the end of the period, Weighted Average Grant Date Fair Value (in dollars per share)			$ 43.34	$ 40.54
Minimum | Common Stock Options
Restricted Stock and Performance Restricted Stock Units
Stock-based awards, vesting period			3 years
Minimum | Restricted Stock and Performance Restricted Stock Units
Restricted Stock and Performance Restricted Stock Units
Stock-based awards, vesting period			1 year
Maximum | Common Stock Options
Restricted Stock and Performance Restricted Stock Units
Stock-based awards, vesting period			5 years
Maximum | Restricted Stock and Performance Restricted Stock Units
Restricted Stock and Performance Restricted Stock Units
Stock-based awards, vesting period			5 years
Former Chairman, Chief Executive Officer and President
Termination
Severance-related charges | $			$ 27.0
Accelerated deferred compensation on termination | $			17.0
Severance payments and other costs | $			$ 10.0
Three Year LTIP Awards | Minimum
Unvested restricted stock and performance restricted stock units activity
Percentage of performance metrics during performance period			0.00%
Three Year LTIP Awards | Maximum
Unvested restricted stock and performance restricted stock units activity
Percentage of performance metrics during performance period			200.00%
2006 Incentive Plan
Unvested restricted stock and performance restricted stock units activity
Granted, Weighted Average Grant Date Fair Value (in dollars per share)		$ 40.68
Termination
Total share-based compensation expense recognized | $			$ 26.0	$ 22.0	$ 40.0
Total unrecognized compensation cost, period of recognition			3 years
2006 Incentive Plan | Three Year LTIP Awards
Restricted Stock and Performance Restricted Stock Units
Stock-based awards, vesting period		3 years
Unvested restricted stock and performance restricted stock units activity
Granted (in shares) | shares		176,088
Total fair values (at vesting) of restricted stock and restricted stock units vested | $		$ 7.2
Weightage Allocated For TSRs Of MSCI US REIT Index		25.00%
Weightage Allocated For TSRs Of NAREIT Health Care Index		75.00%
2014 Incentive Plan | Three Year LTIP Awards
Unvested restricted stock and performance restricted stock units activity
Granted (in shares) | shares	128,762
Granted, Weighted Average Grant Date Fair Value (in dollars per share)	$ 54.97
Total fair values (at vesting) of restricted stock and restricted stock units vested | $	$ 6.9
2014 Incentive Plan | One Year LTIP Award
Unvested restricted stock and performance restricted stock units activity
Granted, Weighted Average Grant Date Fair Value (in dollars per share)	$ 50.82
23.34 - 25.52 | Common Stock Options
Shares Authorized under Stock Option Plan Exercise Price Range
Exercise Price Range, Lower Range Limit (in dollars per share)			$ 23.34
Exercise Price Range, Upper Range Limit (in dollars per share)			$ 25.52
Shares under Options (in shares) | shares			166,000
Weighted Average Exercise Price (in dollars per share)			$ 23.34
Weighted Average Remaining Contractual Term			2 years 1 month 6 days
Currently Exercisable - Shares Under Options (in shares) | shares			166,000
Currently Exercisable - Weighted Average Exercise Price (in dollars per share)			$ 23.34
27.11 - 28.35 | Common Stock Options
Shares Authorized under Stock Option Plan Exercise Price Range
Exercise Price Range, Lower Range Limit (in dollars per share)			27.11
Exercise Price Range, Upper Range Limit (in dollars per share)			$ 28.35
Shares under Options (in shares) | shares			156,000
Weighted Average Exercise Price (in dollars per share)			$ 28.35
Weighted Average Remaining Contractual Term			2 years 9 months 18 days
Currently Exercisable - Shares Under Options (in shares) | shares			156,000
Currently Exercisable - Weighted Average Exercise Price (in dollars per share)			$ 28.35
31.95 - 46.92 | Common Stock Options
Shares Authorized under Stock Option Plan Exercise Price Range
Exercise Price Range, Lower Range Limit (in dollars per share)			31.95
Exercise Price Range, Upper Range Limit (in dollars per share)			$ 46.92
Shares under Options (in shares) | shares			1,416,000
Weighted Average Exercise Price (in dollars per share)			$ 41.72
Weighted Average Remaining Contractual Term			4 years 9 months 18 days
Currently Exercisable - Shares Under Options (in shares) | shares			1,046,000
Currently Exercisable - Weighted Average Exercise Price (in dollars per share)			$ 41.60