Stockholders' Equity - Additional Information (Detail)								2 Months Ended	12 Months Ended			35 Months Ended	36 Months Ended
		Jan. 29, 2019 shares	Dec. 04, 2018 USD ($) $ / shares shares	Sep. 07, 2017 $ / shares shares	Aug. 07, 2017 USD ($) $ / shares shares	Jul. 27, 2017 USD ($)	Feb. 04, 2016 USD ($)	Jan. 29, 2019 $ / shares	Dec. 31, 2018 USD ($) transaction shares	Dec. 31, 2017 USD ($) shares	Dec. 31, 2016 USD ($) shares	Dec. 31, 2018 USD ($) shares	Jan. 22, 2019 USD ($)	Jan. 23, 2019 USD ($)	Jul. 17, 2018 USD ($)	Nov. 01, 2017 USD ($)	Aug. 03, 2017 USD ($)
Class of Stock [Line Items]
Repurchase of common stock							$ 500,000,000		$ 958,696,000	$ 402,393,000	$ 187,979,000
Repurchase of common stock	[1]								$ 958,696,000	$ 402,393,000	$ 187,678,000
Shares acquired (in shares) | shares			1,057,035	263,012	1,491,647				4,911,438	2,854,959	1,259,145	9,025,542
Initial price paid (in usd per share) | $ / shares			$ 176.91		$ 142.46
Final price paid (in usd per share) | $ / shares				$ 142.48
Number of transactions | transaction									2
Repurchase agreements
Class of Stock [Line Items]
Repurchase of common stock									$ 958,700,000	$ 402,400,000	$ 187,700,000	$ 1,500,000,000
Repurchase of common stock			$ 220,000,000		$ 250,000,000
Common Stock
Class of Stock [Line Items]
Stock repurchase program, period in force							18 months
Increase in authorized amount of repurchases						$ 250,000,000									$ 500,000,000	$ 350,000,000
Extension of original period						18 months
Common Stock | Repurchase agreements
Class of Stock [Line Items]
Aggregate authorized repurchase amount			$ 220,000,000														$ 250,000,000
Subsequent Event
Class of Stock [Line Items]
Shares acquired (in shares) | shares		117,751
Final price paid (in usd per share) | $ / shares								$ 187.27
Subsequent Event | Repurchase agreements
Class of Stock [Line Items]
Repurchase of common stock													$ 1,500,000,000
Subsequent Event | Common Stock
Class of Stock [Line Items]
Increase in authorized amount of repurchases														$ 500,000,000
Aggregate authorized repurchase amount														2,100,000,000
Remaining authorized repurchase amount														$ 551,000,000

[1] Reflects the impact of the Company's adoption of Accounting Standards Update 2016-18, Statement of Cash Flows (Topic 230), which was adopted by the Company on January 1, 2018 and applied retrospectively to results for 2017. The adoption of Topic 230 resulted in the statement of cash flows presenting the changes in the total of cash, cash equivalents and restricted cash. As a result, the Company will no longer present transfers between cash and cash equivalents and restricted cash in the statement of cash flows.