Earnings Per Share and Dividends - Additional Information (Detail) (USD $)	0 Months Ended		3 Months Ended		6 Months Ended		0 Months Ended
	Jun. 05, 2014	Apr. 18, 2014	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2014	Jun. 30, 2013	Aug. 06, 2014 Subsequent event
Dividends Payable [Line Items]
Distributions declared per Class A common stock			$ 0.0625	$ 0.0625		$ 0
Distributions declared per Class A common stock, payable date							Sep. 03, 2014
Distributions declared per Class A common stock, record date							Aug. 20, 2014
Dividends to Class A common stockholders	$ 724,000	$ 725,000			$ 1,449,000	$ 0
Dividends declared					$ 1,449,000	$ 0