Quarterly report pursuant to sections 13 or 15(d)

Soft Dollar Arrangements - Additional Information (Detail)

v2.4.0.8
Soft Dollar Arrangements - Additional Information (Detail) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended 6 Months Ended
Jun. 30, 2013
Jun. 30, 2012
Jun. 30, 2013
Jun. 30, 2012
Soft Dollar Arrangements [Abstract]        
Soft dollar credits $ 248 $ 223 $ 496 $ 446