Stock Repurchase Plan - Additional Information (Detail) - USD ($)		6 Months Ended	12 Months Ended
	Jul. 26, 2016	Jun. 30, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Feb. 26, 2015
Equity, Class of Treasury Stock [Line Items]
Number of shares repurchased (in shares)			400,500,000	1,184,700,000	2,023,172,000
Total cost of shares repurchased and cancelled			$ 24,234,000	$ 75,805,000	$ 190,234,000
2015 Stock Repurchase Program [Member]
Equity, Class of Treasury Stock [Line Items]
Number of shares repurchased (in shares)				1,184,700
Total cost of shares repurchased and cancelled				$ 75,800,000
Stock repurchase plan (up to)	$ 100,000,000					$ 100,000,000
Shares repurchased, average cost (in dollars per share)				$ 63.98
2016 Stock Repurchase Program [Member]
Equity, Class of Treasury Stock [Line Items]
Number of shares repurchased (in shares)	0	400,500
Total cost of shares repurchased and cancelled		$ 24,200,000
Shares repurchased, average cost (in dollars per share)		$ 60.51