Stock Options - Changes in Nonvested Stock Options (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013
Number of Shares
Nonvested beginning balance	457,603
Granted	190,500
Vested	(161,527)
Forfeited	(30,325)
Nonvested ending balance	456,251
Weighted- Average Grant Date Fair Value Per Share
Nonvested beginning balance	$ 6.49
Granted	$ 10.95
Vested	$ 6.69
Forfeited	$ 7.11
Nonvested ending balance	$ 8.24