Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands		Total		Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock
Beginning Balance at Dec. 31, 2016		$ 3,084,038		$ 121	$ 2,074,094	$ 2,218,721	$ (666,403)	$ (542,495)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		740,200	[1],[2]			740,200
Other comprehensive income from currency exchange, net of tax		114,546					114,546
Other comprehensive income, net of tax		114,546
Acquisition of common stock		(402,393)						(402,393)
Share-based compensation expense	[3]	93,297			93,297
Issuance of common stock		46,834		1	46,833
Ending Balance at Dec. 31, 2017		3,676,522		122	2,214,224	2,958,921	(551,857)	(944,888)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		811,483				811,483
Other comprehensive income from currency exchange, net of tax		(362,001)					(362,001)
Other comprehensive income, net of tax		(362,001)
Acquisition of common stock		(958,696)			(33,000)			(925,696)
Share-based compensation expense	[3]	69,939			69,939
Issuance of common stock		55,681		1	55,680
Ending Balance at Dec. 31, 2018		3,340,180		123	2,306,843	3,817,656	(913,858)	(1,870,584)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		895,073	[4],[5]			895,073
Other comprehensive income, net of tax		(58,607)					(58,607)
Acquisition of common stock		(694,909)			(42,000)			(652,909)
Share-based compensation expense		60,953			60,953
Issuance of common stock		168,926		1	168,925
Ending Balance at Dec. 31, 2019		$ 3,711,616	[6]	$ 124	$ 2,494,721	$ 4,712,729	$ (972,465)	$ (2,523,493)

[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.

[2] The Company applied the modified retrospective transition method when adopting ASC 606, therefore the Company's 2017 prior period results were not restated to reflect ASC 606.

[3] Comparable disclosure provided to align with 2019 presentation. Activity previously included with issuance of common stock.

[4] Reflects the impact of the Company's adoption of ASU 2016-02 "Leases", on January 1, 2019 using the modified retrospective transition method. The adoption of the Leases guidance resulted in an adjustment to other assets, other current liabilities and other noncurrent liabilities in our consolidated balance sheet for the cumulative effect of applying the standard. Financial results reported in periods prior to 2019 are unchanged.

[5] Reflects the impact of the Company's adoption of ASU 2016-02 "Leases", on January 1, 2019, using a modified retrospective transition method. Under this method, financial results reported in periods prior to 2019 are unchanged. Refer to footnote 14.

[6] Reflects the impact of the Company's adoption of ASU 2016-02 "Leases", on January 1, 2019, using a modified retrospective transition method. Under this method, financial results reported in periods prior to 2019 are unchanged. Refer to footnote 14.