Related-Party Transactions - Additional Information (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	1 Months Ended	3 Months Ended				6 Months Ended		0 Months Ended		3 Months Ended		6 Months Ended			0 Months Ended
	May 31, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Apr. 01, 2014 Blackstone and Affiliates [Member]	Apr. 24, 2013 Blackstone and Affiliates [Member]	Jun. 30, 2014 Blackstone and Affiliates [Member]	Jun. 30, 2013 Blackstone and Affiliates [Member]	Jun. 30, 2014 Blackstone and Affiliates [Member]	Jun. 30, 2013 Blackstone and Affiliates [Member]	Apr. 24, 2013 Blackstone and Affiliates [Member]	Jul. 01, 2014 Blackstone and Affiliates [Member] Subsequent Events [Member]
Related Party Transaction [Line Items]
Advisory Agreement, fees										$ 0	$ 1,874	$ 0	$ 2,799
Termination fee paid														46,300
Write-off of 2013 prepaid advisory fee									3,772
Termination of advisory agreement					50,072		50,072				50,072		50,072
Cash dividends declared per share	$ 0.21	$ 0.21	$ 0.20	$ 0.20	$ 0.20	$ 0.41	$ 0.20
Cash dividends declare date	2014-05		2014-03
Cash dividends record date	Jun. 20, 2014	Jun. 20, 2014	Mar. 20, 2014	Dec. 20, 2013
Cash dividends paid date	Jul. 01, 2014	Jul. 01, 2014	Apr. 01, 2014	Jan. 03, 2014
Dividends paid to stockholders						$ 35,407	$ 184	$ 7,849							$ 4,252