Annual report pursuant to Section 13 and 15(d)

Summary of Stock Option Activity (Detail)

v3.3.1.900
Summary of Stock Option Activity (Detail) - $ / shares
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Number of Options    
Number of Options, Beginning balance 14,584 22,022
Number of Options, Exercised (14,584) (7,438)
Number of Options, Ending balance   14,584
Number of Options, Vested at December 31   14,584
Weighted Average Exercise Price    
Weighted Average Exercise Price, Beginning balance $ 7.63 $ 7.63
Weighted Average Exercise Price, Exercised $ 7.63 7.63
Weighted Average Exercise Price, Ending balance   7.63
Weighted Average Exercise Price, Vested options   $ 7.63