Shareholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		12 Months Ended				224 Months Ended	324 Months Ended
	May 05, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2016	Dec. 31, 2020	Dec. 31, 2020
Class of Stock [Line Items]
Cumulative shares repurchased							122,969
Issuance of shares under stock purchase plan						13,523
Total intrinsic value of options exercised		$ 82,000	$ 117,000	$ 79,000
Total unrecognized share-based compensation cost		$ 52,000
Unrecognized share-based compensation cost, weighted average period		1 year 7 months 6 days
The Amended 2017 Plan
Class of Stock [Line Items]
Shares authorized for grant	5,500
Weighted average fair value of award granted during the period		$ 113.82	$ 74.00	$ 75.73
Shares available for granting of awards		2,567
The Amended 2017 Plan | Upper End | Director
Class of Stock [Line Items]
Fair value of annual equity award grant per participant		$ 600
The Amended 2017 Plan | Upper End | Board of Directors Chairman
Class of Stock [Line Items]
Fair value of annual equity award grant per participant		$ 800
Restricted Stock Units (RSUs)
Class of Stock [Line Items]
Award vesting period	3 years
Number of common stock issued per unit based award upon vesting		100.00%
Weighted average fair value of award granted during the period		$ 113.82
Shares granted		327
Weighted average grant date fair value of shares unvested		$ 89.74	$ 73.92			$ 73.92	$ 73.92
Number of unsettled shares, vested		477
Weighted average grant date fair value of shares vested		$ 74.16
Restricted Shares
Class of Stock [Line Items]
Weighted average fair value of award granted during the period		$ 113.82
Number of shares, unvested		0
Shares granted		12
Performance Shares
Class of Stock [Line Items]
Number of common stock issued per unit based award upon vesting		100.00%
Number of shares, unvested		173
Shares granted		75	95	96
Maximum Adjustment Factor		200.00%
Minimum Adjustment Factor		50.00%
Shares issued if minimum performance thresholds are not achieved		0
Weighted average grant date fair value of shares unvested		$ 90.77
Number of unsettled shares, vested		200
Weighted average grant date fair value of shares vested		$ 75.73
Employee Stock Option Plan | Upper End
Class of Stock [Line Items]
Maximum contractual term					10 years
Employee Stock Purchase Plan
Class of Stock [Line Items]
Shares authorized for grant		15,305
Purchase price percentage of fair market value		85.00%
Amount withheld employee stock purchase plan		$ 33,073
Non-Discretionary Plan
Class of Stock [Line Items]
Number of shares authorized for repurchase		40,000
Remaining number of shares authorized for repurchase		0