Schedule I - Condensed Financial Information of Parent Company (Balance Sheets) (Parenthetical) (Detail) - $ / shares	Dec. 31, 2015	Dec. 31, 2014	Apr. 29, 2014
Condensed Balance Sheet Statements, Captions [Line Items]
Series A preferred stock, par value	$ 0.01	$ 0.01
Series A preferred stock, shares authorized	18,000	18,000
Series A preferred stock, shares outstanding	18,000	12,600
Common stock, par value	$ 0.01	$ 0.01	$ 0.01
Common stock, shares authorized	400,000,000	400,000,000
Common stock, shares outstanding	254,289,261	252,728,684
Parent Company [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Series A preferred stock, par value	$ 0.01	$ 0.01
Series A preferred stock, shares authorized	18,000	18,000
Series A preferred stock, shares outstanding	18,000	12,600
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	400,000,000	400,000,000
Common stock, shares outstanding	254,289,261	252,728,684