Related-Party Transactions - Additional Information (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	1 Months Ended				3 Months Ended		9 Months Ended
	Sep. 30, 2013	Jun. 30, 2013	Apr. 24, 2013	Mar. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Related Party Transaction [Line Items]
Termination of advisory agreement							$ 50,072
Cash dividend declared	$ 0.20	$ 0.20			$ 0.20		$ 0.40	$ 6.07
Dividend declared to stockholders				500,000			36,144
Blackstone and Affiliates [Member]
Related Party Transaction [Line Items]
Advisory Agreement, fees					0	2,264	2,799	5,075
Agreement termination date			Apr. 24, 2013
Termination fee paid			46,300
Write off of 2013 Prepaid advisory fees			3,772
Termination of advisory agreement			50,072
Dividend declared to stockholders	$ 11,749	$ 11,749		$ 500,000