Schedule of Common Stock Repurchases (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	6 Months Ended
Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Stockholders Equity Note [Abstract]
Shares repurchased		19,246		62,540	148,813
Cost of shares repurchased	$ 44,268	$ 12,666	$ 80,486	$ 44,300	$ 93,200
Average price per share repurchased		$ 658.09		$ 707.84	$ 625.96

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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