Stock-based Compensation - Fair Value Assumptions for Stock Options (Detail) - Stock Option [Member]	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected dividend yield	1.53%	1.77%	2.01%
Expected volatility	40.32%	42.04%	42.48%
Expected term	7 years 3 months 18 days	7 years 3 months 18 days	7 years 4 months 24 days
Risk-free interest rate	1.96%	2.18%	1.53%