Shareholders' Equity - Summary of Changes in Shareholders' Equity (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2017
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	$ 2,119,439	$ 1,607,571	$ 1,808,562	$ 1,605,492
Cumulative-effect adjustment from adoption of ASU 2014-09, net of tax					$ 2,196
Net income	223,787	195,816	622,402	565,039
Purchase of common stock for treasury	(61,063)	(173,831)	(365,542)	(657,369)
Equity-based compensation	20,770	23,586	58,680	51,690
Proceeds from Options exercised	68,524	29,174	247,355	115,268
Ending Balance	2,371,457	1,682,316	2,371,457	1,682,316
Common Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	206	206	206	206
Ending Balance	206	206	206	206
Additional Paid-In-Capital [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	1,962,156	1,721,696	1,820,223	1,644,197
Equity-based compensation	20,770	23,586	58,680	51,690
Proceeds from Options exercised	68,524	29,174	247,355	115,268
Treasury stock issued upon option exercise and restricted share vesting	(31,270)	(12,133)	(106,078)	(48,832)
Ending Balance	2,020,180	1,762,323	2,020,180	1,762,323
Retained Earnings [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	7,429,948	6,603,359	7,031,333	6,231,940
Cumulative-effect adjustment from adoption of ASU 2014-09, net of tax					$ 2,196
Net income	223,787	195,816	622,402	565,039
Ending Balance	7,653,735	6,799,175	7,653,735	6,799,175
Treasury Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	(7,272,871)	(6,717,690)	(7,043,200)	(6,270,851)
Purchase of common stock for treasury	(61,063)	(173,831)	(365,542)	(657,369)
Treasury stock issued upon option exercise and restricted share vesting	31,270	12,133	106,078	48,832
Ending Balance	(7,302,664)	(6,879,388)	(7,302,664)	(6,879,388)
Deferred Compensation Trust [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	(16,912)	(17,148)	(16,937)	(17,383)
Deferred compensation activity, net	0	220	25	455
Ending Balance	(16,912)	(16,928)	(16,912)	(16,928)
Deferred Compensation Liability [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	16,912	17,148	16,937	17,383
Deferred compensation activity, net	0	(220)	(25)	(455)
Ending Balance	$ 16,912	$ 16,928	$ 16,912	$ 16,928

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Amount after tax of increase (decrease) to equity or (increase) decrease to net assets, resulting from the cumulative effect adjustment of a new accounting principle applied in the period of adoption.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Value of stock issued as a result of the exercise of stock options.

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Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

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