Employee Stock Plans - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Employee Benefits Disclosure [Line Items]
Common stock reserved and available for issuance under the Comprehensive Plan	17,000,000
Compensation expense	$ 22.0		$ 18.0		$ 16.0
Granted	2,000,000		2,200,000		1,800,000
Vested	1,300,000		1,200,000		900,000
Liability awards as a percentage of restricted stock awards granted	94.00%
Restricted Stock | Executive Officer
Employee Benefits Disclosure [Line Items]
Compensation expense	18.0		14.0		12.0
Granted	1,500,000		1,700,000		1,600,000
Vested	800,000	[1]	800,000	[1]	600,000	[1]
Employee Stock Option
Employee Benefits Disclosure [Line Items]
Compensation expense	1.8		1.8		1.6
Granted	393,000		420,000		201,000
Stock options outstanding	800,000
Stock options exercisable	800,000
Weighted average remaining life - outstanding	8 years
Weighted average remaining life - exercisable	8 years
Weighted average exercise price - outstanding	$ 17.35
Weighted average exercise price - exercisable	$ 17.35
Weighted average volatility, minimum	34.00%
Weighted average volatility, maximum	66.00%
Weighted average risk free rate, minimum	1.00%
Weighted average risk free rate, maximum	1.80%
Weighted average dividend yield	3.50%
Expected life	5 years 6 months
Other Stock Plans
Employee Benefits Disclosure [Line Items]
Compensation expense	$ 2.2		$ 2.0		$ 1.9
Granted	118,000		116,000		84,000
Vesting term	3 years
Employee stock purchase plan discount percentage	10.00%
Senior Executive Plan | Restricted Stock | Executive Officer
Employee Benefits Disclosure [Line Items]
Granted	1,500,000
Restricted stock awards	0
Shares vesting percentage	50.00%
Payout comparison	Vesting of restricted stock awards is based on (1) the achievement of relative total shareholder return (“TSR”) and (2) the company and personal performance of employees attributable to specific management business objectives. Approximately 50% of the restricted stock awards are based on the satisfaction of the TSR compared to (i) the NAREIT index, (ii) the Standard & Poor’s index, and (iii) a Selected Lodging Company index that serves as a relevant industry/asset specific measurement to our competitors, with the remaining 50% based on the achievement of management business objectives.
Senior Executive Plan | Restricted Stock | Executive Officer | Shareholders Return
Employee Benefits Disclosure [Line Items]
Shares vesting percentage	50.00%
Senior Executive Plan | Employee Stock Option | Executive Officer
Employee Benefits Disclosure [Line Items]
Granted	400,000
Stock option exercise price	$ 19.57
Stock options outstanding	0

[1] Shares that vest at December 31 of each year are issued to the employees in the first quarter of the following year, although the requisite service period is complete. Accordingly, the 0.4 million shares issued in 2014 include shares vested at December 31, 2013, after adjusting for shares withheld to meet employee tax requirements. The shares withheld for employee tax requirements were valued at $6.1 million, $5.5 million and $9.5 million, for 2014, 2013 and 2012, respectively.