Stockholders' Equity - Stock Repurchase Program (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate purchase price	$ 0	$ 100,008	$ 227,895	$ 100,008
Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate purchase price			$ 227,895
Shares repurchased (in shares)	0	407	1,209	407
Average price paid per share (in dollars per share)			$ 188.61

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Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

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Equity impact of the value of stock that has been repurchased during the period and has not been retired and is not held in treasury. Some state laws may mandate the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

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Total cost of shares repurchased divided by the total number of shares repurchased.

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