Equity - Additional Information (Detail) (USD $)	3 Months Ended				0 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012	Jan. 14, 2014 Class A Common Stock [Member]
Class of Stock [Line Items]
Increase in total equity	$ 251,700,000
Total equity	1,008,400,000	756,750,000	162,445,000	153,453,000
Total stock, shares authorized	200,000,000
Common stock, shares authorized	100,000,000	100,000,000
Preferred stock, shares authorized	100,000,000
Additional shares issued					9,775,000
Additional shares, public offering price					$ 26.25
Issuance of additional shares, net proceeds after underwriter discounts and other offering expenses					256,100,000
Preferred stock issued	0
Preferred stock outstanding	0
Dividends declared, amount	18,900,000		0
Dividends per common stock	$ 0.48
Date of dividend paid	Apr. 15, 2014
Date of dividend declared	Mar. 14, 2014
Record date of dividend paid	Mar. 31, 2014
Plan adoption date	March 25, 2014
Accumulated other comprehensive income	834,000	798,000	0
Unrealized gain on foreign currency remeasurement	$ 36,000