Schedule I - Stockholders' Equity - Additional Information (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	0 Months Ended	3 Months Ended	12 Months Ended		0 Months Ended			12 Months Ended
	Apr. 08, 2013	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Apr. 24, 2013	Apr. 09, 2014	Dec. 17, 2013	Dec. 31, 2012	Aug. 12, 2014	Dec. 16, 2014	Apr. 19, 2013	Apr. 18, 2013	Apr. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
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	$ 0.01
Common stock, shares authorized		1,000,000,000	1,000,000,000	1,000,000,000
Preferred stock, shares authorized		100,000,000	100,000,000	100,000,000
Preferred stock, par value		$ 0.01	$ 0.01	$ 0.01
Net proceeds received from offering				$ 245,441
Number of shares repurchased		4,105,970	4,105,970	1,500,000
Share Repurchase Program, authorized amount		15,000	15,000						250,000
Share Repurchase Program, beginning date			Jan. 01, 2015
Shares repurchased		855,970	2,605,970	1,500,000
Stock repurchase during period under Share Repurchase Program, average price per share		$ 17.50
Share Repurchase Program, remaining authorized repurchase amount		235,000	235,000
Treasury stock purchases settled in January 2015		5,650	5,650
Stock repurchased during period, total cost		15,000	65,708	44,163
Treasury stock at cost		109,871	109,871	44,163
Amended Share Repurchase Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share Repurchase Program, authorized amount during remainder of 2014										15,000
Share Repurchase Program, beginning date			Dec. 17, 2014
Omnibus Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance											15,000,000
Initial Public Offering [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock issued through initial public offering, shares					10,000,000
Shares offered and sold by the selling shareholders					19,900,000
Offering price per share					$ 27.00							$ 27.00
Net proceeds received from offering					245,400
Underwriters Over-Allotment Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares offered and sold by the selling shareholders					3,900,000	2,250,000
Secondary Offering [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares offered and sold by the selling shareholders						17,250,000	18,000,000
Number of shares repurchased				1,500,000									1,750,000
Treasury stock at cost		109,871	109,871	44,163
Parent Company [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock split description			On April 7, 2013, the Parent's Board authorized an eight-for-one split of the Parent's common stock which was effective on April 8, 2013.The Parent’s historical 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	$ 0.01
Common stock, shares authorized		1,000,000,000	1,000,000,000	1,000,000,000
Preferred stock, shares authorized		100,000,000	100,000,000	100,000,000
Preferred stock, par value		$ 0.01	$ 0.01	$ 0.01
Number of shares repurchased		4,105,970	4,105,970	1,500,000
Share Repurchase Program, authorized amount									250,000
Share Repurchase Program, beginning date			Jan. 01, 2015
Shares repurchased		855,970
Stock repurchase during period under Share Repurchase Program, average price per share		$ 17.50
Share Repurchase Program, remaining authorized repurchase amount		235,000	235,000
Treasury stock purchases settled in January 2015		5,650	5,650					0
Stock repurchased during period, total cost		15,000
Treasury stock at cost		109,871	109,871	44,163
Restricted payments to the parent			65,708	44,163				0
Parent Company [Member] | Amended Share Repurchase Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share Repurchase Program, authorized amount during remainder of 2014										15,000
Share Repurchase Program, beginning date			Dec. 17, 2014
Parent Company [Member] | Initial Public Offering [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock issued through initial public offering, shares					10,000,000
Shares offered and sold by the selling shareholders					19,900,000
Offering price per share					$ 27.00
Net proceeds received from offering					245,400
Parent Company [Member] | Underwriters Over-Allotment Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares offered and sold by the selling shareholders					3,900,000	2,250,000
Parent Company [Member] | Secondary Offering [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares offered and sold by the selling shareholders						17,250,000	18,000,000
Number of shares repurchased				1,500,000									1,750,000
Treasury stock at cost		109,871	109,871	44,163
Restricted payments to the parent			$ 65,708	$ 44,163