Annual report pursuant to Section 13 and 15(d)

Subsequent Event - Dividend Declaration - Additional Information (Detail)

v2.4.0.6
Subsequent Event - Dividend Declaration - Additional Information (Detail) (Subsequent Event, USD $)
3 Months Ended 12 Months Ended
Feb. 12, 2013
Dec. 31, 2012
Subsequent Event
   
Subsequent Event [Line Items]    
Cash Dividends declared per common share $ 0.21  
Dividend Payable Date   Mar. 15, 2013