Derivative and Hedging Activities - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
3 Months Ended 9 Months Ended
Sep. 30, 2013
Sep. 30, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]    
Loss from cash net settlement of the off-market financing element associated with the derivatives from merger $ 0.1 $ 0.1
Derivative instruments loss estimated to be reclassified from accumulated OCI as an increase to interest expense   $ 0.4