Quarterly report pursuant to Section 13 or 15(d)

Subsequent Events - Additional Information (Detail)

v2.4.0.8
Subsequent Events - Additional Information (Detail) (USD $)
3 Months Ended 9 Months Ended 1 Months Ended
Sep. 30, 2013
Jun. 30, 2013
Mar. 31, 2013
Sep. 30, 2012
Sep. 30, 2013
Sep. 30, 2012
Oct. 28, 2013
Subsequent Event [Member]
Subsequent Event [Line Items]              
Dividend declared per common share $ 0.30 $ 0.30 $ 0.30 $ 0.30 $ 0.90 $ 0.90 $ 0.30
Dividend declaration date Jul. 29, 2013 Apr. 29, 2013 Feb. 19, 2013       Oct. 28, 2013
Dividend payment date Aug. 27, 2013 May 28, 2013 Mar. 19, 2013       Nov. 26, 2013
Dividend date of record             Nov. 12, 2013