Preferred Stock - Additional Information (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Auction Market Preferred Securities, Stock Series [Line Items]
Preferred Stock, shares authorized (shares)	10,000,000
Preferred Stock, par value per share (usd per share)	$ 0.01	$ 0.01
6.75% Series C Cumulative Redeemable Perpetual Preferred Stock
Auction Market Preferred Securities, Stock Series [Line Items]
Preferred Stock, par value per share (usd per share)	$ 0.01	$ 0.01
Dividend rate (percentage)	6.75%