Summary of Treasury Stock Activity (Parenthetical) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013
Schedule of Treasury Stock [Line Items]
Common stock repurchased value as result of restricted stock forfeitures and canceled	$ 0.001
Minimum
Schedule of Treasury Stock [Line Items]
Market Value of Restricted Shares	$ 22.40
Maximum
Schedule of Treasury Stock [Line Items]
Market Value of Restricted Shares	$ 30.23