Non-Vested Stock Option Activity (Detail) - Stock Option [Member]	12 Months Ended
	Dec. 31, 2015 $ / shares shares
Share Based Compensation [Line Items]
Non-vested stock options beginning balance | shares	250,000
Granted | shares	590,647
Vested | shares	(62,500)
Forfeited | shares	(2,153)
Non-vested stock options ending balance | shares	775,994
Non-Vested Stock Options Begining Balance, Weighted Average Grant Date Fair Value | $ / shares	$ 26.65
Non-Vested Stock Options Granted, Weighted Average Grant Date Fair Value | $ / shares	31.73
Non-Vested Stock Options Vested, Weighted Average Grant Date Fair Value | $ / shares	26.65
Non-Vested Stock Options Forfeited, Weighted Average Grant Date Fair Value | $ / shares	43.63
Non-Vested Stock Options Ending Balance, Weighted Average Grant Date Fair Value | $ / shares	$ 30.47