Common Stock Repurchase Program - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Thousands		1 Months Ended				9 Months Ended	12 Months Ended			36 Months Ended
	May 04, 2016	Feb. 22, 2019	Dec. 31, 2018	Feb. 28, 2018	Aug. 31, 2017	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	May 31, 2018	Apr. 28, 2016	Apr. 23, 2014
Share Repurchases [Line Items]
Common stock repurchased and retired							$ 399,999,000	$ 300,002,000	$ 103,793,000
Additional Paid-in Capital
Share Repurchases [Line Items]
Common stock repurchased and retired							18,992,000	10,252,000	5,583,000
Retained Earnings
Share Repurchases [Line Items]
Common stock repurchased and retired							381,007,000	289,750,000	$ 98,210,000
April 2014 Stock Repurchase Program
Share Repurchases [Line Items]
Repurchase of common stock, common stock authorized													$ 300,000,000.0
Common stock repurchased and retired (shares)										1,600
Common stock repurchased and retired								$ 3,800,000		$ 106,200,000
Accelerated share repurchase agreement amount	$ 50,000,000.0									$ 190,000,000.0
Accelerated share repurchase (in shares)								40		3,200
Accelerated share repurchases price per share (in dollars per share)								$ 96.37
April 2016 Stock Repurchase Program
Share Repurchases [Line Items]
Repurchase of common stock, common stock authorized												$ 300,000,000.0
2017 ASR
Share Repurchases [Line Items]
Common stock repurchased and retired (shares)				700	400			200
Common stock repurchased (in dollars per share)					$ 146.48			$ 243.40
Common stock repurchased and retired				$ 200,000,000.0				$ 50,000,000.0
Accelerated share repurchases price per share (in dollars per share)				$ 293.21
May 2018 Repurchase [Member]
Share Repurchases [Line Items]
Repurchase of common stock, common stock authorized											$ 600,000,000.0
Common stock repurchased and retired (shares)		800	200					100
Common stock repurchased and retired		$ 200,000,000.0						$ 50,000,000.0
Authorized repurchase amount remaining			$ 50,000,000.0				$ 100,000,000.0	$ 50,000,000.0
Treasury Stock Acquired, Average Cost Per Share		$ 264.93	$ 213.18					$ 356.54
Accelerated Stock Repurchase Agreement, 2019 ASR [Member]
Share Repurchases [Line Items]
Common stock repurchased and retired (shares)						1,100
Common stock repurchased and retired						$ 200,000,000.0
Treasury Stock Acquired, Average Cost Per Share						$ 176.61