Stockholders' Equity - Schedule of Share Repurchase Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended
Dec. 31, 2019	Sep. 30, 2019	Dec. 31, 2019
Stockholders Equity Note [Abstract]
Shares repurchased (in shares)	137,432		318,361
Average price per share	$ 181.94		$ 188.08
Shares repurchased, value	$ 25,002	$ 34,874	$ 59,900

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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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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