Stock-Based Compensation - Summary of Exercisable Stock Options (Detail) shares in Thousands	12 Months Ended
	Dec. 31, 2016 $ / shares shares
$32.315-$40.00 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Options Exercisable (in shares) | shares	2,141
Exercisable, weighted average per share exercise price | $ / shares	$ 36.12
Weighted average remaining years	4 years 10 months 24 days
$40.01-$50.00 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Options Exercisable (in shares) | shares	491
Exercisable, weighted average per share exercise price | $ / shares	$ 41.36
Weighted average remaining years	7 years 2 months 12 days
$50.01-$54.635 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Options Exercisable (in shares) | shares	289
Exercisable, weighted average per share exercise price | $ / shares	$ 54.64
Weighted average remaining years	8 years 2 months 12 days
$32.315-$54.635 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Options Exercisable (in shares) | shares	2,921
Exercisable, weighted average per share exercise price | $ / shares	$ 38.84
Weighted average remaining years	5 years 7 months 6 days