Stockholders' Equity - Additional Information (Detail) (USD $)	0 Months Ended		9 Months Ended		12 Months Ended		0 Months Ended				9 Months Ended	0 Months Ended		9 Months Ended		0 Months Ended
	Oct. 06, 2014	Apr. 08, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Aug. 12, 2014	Sep. 30, 2014 2.25x Performance Restricted Shares [Member]	Sep. 30, 2014 2.75x Performance Restricted Shares [Member]	Apr. 24, 2013 Senior Notes [Member]	Apr. 24, 2013 Senior Notes [Member] Prior to December 1, 2014 [Member]	Sep. 30, 2014 Senior Notes [Member] Prior to December 1, 2014 [Member]	Apr. 24, 2013 Term B Loan [Member]	Apr. 24, 2013 Initial Public Offering [Member]	Sep. 30, 2014 Initial Public Offering [Member]	Apr. 24, 2013 Initial Public Offering [Member]	Apr. 24, 2013 Initial Public Offering [Member] Senior Notes [Member]	Apr. 09, 2014 Underwriters Over-Allotment Option [Member]	Apr. 24, 2013 Underwriters Over-Allotment Option [Member]	Apr. 09, 2014 Secondary Offering [Member]	Dec. 17, 2013 Secondary Offering [Member]	Sep. 30, 2014 Secondary Offering [Member]	Apr. 30, 2014 Secondary Offering [Member]	Apr. 09, 2014 Secondary Offering [Member]	Dec. 31, 2013 Secondary Offering [Member]	Dec. 17, 2013 Secondary Offering [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares issued			89,981,272		89,900,453																		0		0
Unvested shares of common stock			3,266,721
Stock split description			On April 7, 2013, the Board authorized an eight-for-one split of the Company's common stock which was effective on April 8, 2013. The Company's historical share and per share information has been retroactively adjusted to give effect to this stock split.
Stock split conversion ratio		8
Common stock, par value			$ 0.01		$ 0.01
Common stock, shares authorized			1,000,000,000		1,000,000,000
Preferred stock, shares authorized			100,000,000		100,000,000
Preferred stock, par value			$ 0.01		$ 0.01
Shares of common stock issued through initial public offering, shares													10,000,000
Shares offered and sold by the selling stockholders													19,900,000				2,250,000	3,900,000	17,250,000	18,000,000
Net proceeds received from offering													$ 245,400,000
Net proceeds received used to redeem 11% Senior Notes									140,000,000							140,000,000
Redemption price for Senior Notes percentage										111.00%	100.00%
Senior Notes redemption terms														A provision in the indenture governing the Senior Notes that permits the Company to redeem up to 35% of the aggregate principal amount of the Senior Notes with the net cash proceeds of certain equity offerings.
Payment made to affiliate for termination of Advisory Agreement															46,300,000
Net proceeds from offering to repay the outstanding debt												37,000,000
Secondary offering costs			747,000		1,407,000
Number of shares repurchased			3,250,000		1,500,000																	1,750,000		1,500,000
Treasury stock at cost			94,871,000		44,163,000																94,871,000			44,163,000
Dividends paid to common stockholders			53,639,000	18,124,000
Dividends payable			18,647,000		17,939,000
Dividends paid	18,200,000
Dividends payable							1,770,000	1,770,000
Share repurchase program, authorized amount						$ 250,000,000
Share repurchase program, beginning date			Jan. 01, 2015