Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair Value Disclosures [Abstract]
Hedge derivative expiration period	One-month period
Proceeds from the sales and maturities of securities available-for-sale	$ 35.2	$ 17.6	$ 43.4