Equity - Schedule of Dividend Activity (Detail) - $ / shares		3 Months Ended		9 Months Ended
	Sep. 14, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Equity [Abstract]
Dividends declared per share of common stock	$ 0.62	$ 0.62	$ 0.50	$ 1.66	$ 1.46