Capital Stock - Additional Information (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	1 Months Ended	9 Months Ended		12 Months Ended
	Mar. 19, 2013	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Mar. 19, 2012 Reorganization Adjustments [Member]
Capital Stock Distribution [Line Items]
Common stock, shares authorized		500,000,000		500,000,000	500,000,000
Preferred stock, shares authorized		5,000,000		5,000,000
Preferred stock, par value		$ 0.00001		$ 0.00001
Common stock, par value		$ 0.00001		$ 0.00001	$ 0.00001
Common stock, shares issued		201,842,351		201,156,078	200,000,000
Amount of restricted share grants		$ 700		$ 550
Unamortized value of unvested restricted share grant		806		407
Stock-based compensation		$ 301	$ 0
Award vesting period		3 years
Award vesting rights		1/3 per year
Number of shares vested	385,364	385,364
Unvested shares		1,456,987		1,156,078
Per share of unvested shares of common stock		$ 0.0001
Common stock, shares outstanding		201,842,351		201,156,078	200,000,000
Preferred stock, shares issued		0		0
Preferred stock, shares outstanding		0		0