Subsequent Events - Additional Information (Detail) (2014 Senior Unsecured Notes [Member], USD $) In Millions, unless otherwise specified	3 Months Ended	0 Months Ended
	Mar. 31, 2014	Apr. 17, 2014 Subsequent Event [Member]
Subsequent Event [Line Items]
Unsecured senior notes, value of offering		$ 300
Unsecured senior notes, interest rate		5.50%
Debt instrument, maturity date	May 01, 2024
Senior notes frequency of periodic payment	Semi-annually
Senior notes, earliest redemption date	May 01, 2019
Senior notes, repurchase price percentage on principal amount plus accrued and unpaid interest		101.00%
Notes redemption term	On or after May 1, 2019, we may redeem some or all of the Notes at a premium that will decrease over time. In addition, at any time and from time to time prior to May 1, 2017, we may redeem up to 35% of the aggregate principal amount of the 2014 Senior Unsecured Notes using the proceeds of one or more equity offerings.