Stockholders' Equity - Share-based Compensation Plans (Detail)		9 Months Ended
	Apr. 27, 2016 shares	Sep. 30, 2016 plan shares
Share-based Compensation Arrangement by Share-based Payment Award
Stock dividend, number of shares of Class C capital stock each shareholder of Class A and Class B common stock will receive for every share they hold	2
Share-based employee compensation plans, number | plan		2
2012 Plan
Share-based Compensation Arrangement by Share-based Payment Award
Equity incentive plan shares authorized		25,000,000
Shares reserved for issuance increase, percentage		2.50%
2012 Plan | Maximum
Share-based Compensation Arrangement by Share-based Payment Award
Shares reserved for issuance increase, date range		Jan. 01, 2026