Stockholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended					3 Months Ended	8 Months Ended	10 Months Ended	12 Months Ended
	May 31, 2016	Apr. 30, 2016	Mar. 31, 2016	Jul. 31, 2014	Jun. 30, 2014	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	May 01, 2016	Feb. 28, 2014
Stockholders' equity
Preferred stock redemption charge									$ 4,052
Proceeds from preferred stock offerings									190,000
Payment of preferred stock offering costs									6,640
Net proceeds from sale of common stock									$ 54,192		$ 283,456
Series D Cumulative Redeemable Preferred Stock
Stockholders' equity
Number of shares redeemed (in shares)		4,600,000
Redemption price (in dollars per share)		$ 25.00
Preferred stock redemption charge		$ 4,100
Preferred stock, Cumulative Redeemable Preferred Stock, shares outstanding (in shares)							0	0	0	4,600,000		0
Liquidation preference (in dollars per share)										$ 25.00
Preferred stock, Cumulative Redeemable Preferred Stock, dividend rate (as a percent)						8.00%				8.00%
Series E Cumulative Redeemable Preferred Stock
Stockholders' equity
Redemption price (in dollars per share)			$ 25.00			$ 25.00
Preferred stock, Cumulative Redeemable Preferred Stock, shares outstanding (in shares)							4,600,000	4,600,000	4,600,000	0
Number of shares of preferred stock sold (in shares)			4,600,000
Liquidation preference (in dollars per share)			$ 25.00			$ 25.00	$ 25.00	$ 25.00	$ 25.00
Proceeds from preferred stock offerings			$ 115,000
Payment of preferred stock offering costs			$ 4,000
Preferred stock, Cumulative Redeemable Preferred Stock, dividend rate (as a percent)								6.95%
Series F Cumulative Redeemable Preferred Stock
Stockholders' equity
Redemption price (in dollars per share)	$ 25.00
Preferred stock, Cumulative Redeemable Preferred Stock, shares outstanding (in shares)							3,000,000	3,000,000	3,000,000	0
Number of shares of preferred stock sold (in shares)	3,000,000
Liquidation preference (in dollars per share)	$ 25.00						$ 25.00	$ 25.00	$ 25.00
Proceeds from preferred stock offerings	$ 75,000
Payment of preferred stock offering costs	$ 2,600
Preferred stock, Cumulative Redeemable Preferred Stock, dividend rate (as a percent)							6.45%
Common Stock
Stockholders' equity
Net proceeds from sale of common stock					$ 262,500
Number of shares sold or issued (in shares)					18,000,000
Common Stock | At The Market
Stockholders' equity
Net proceeds from sale of common stock									$ 54,200		$ 21,000
Number of shares sold or issued (in shares)									3,564,047		1,352,703
Stock issuance program, remaining amount							$ 73,300	$ 73,300	$ 73,300
Common Stock | Maximum | At The Market
Stockholders' equity
Stock issuance program, authorized amount													$ 150,000
Wailea Beach Resort | Common Stock
Stockholders' equity
Number of shares issued in connection with acquisition (in shares)				4,034,970
Total equity issued directly to seller				$ 60,000
Preferred Stock | Series D Cumulative Redeemable Preferred Stock
Stockholders' equity
Number of shares redeemed (in shares)									(4,600,000)
Preferred Stock | Series E Cumulative Redeemable Preferred Stock
Stockholders' equity
Number of shares of preferred stock sold (in shares)									4,600,000
Preferred Stock | Series F Cumulative Redeemable Preferred Stock
Stockholders' equity
Number of shares of preferred stock sold (in shares)									3,000,000