Stockholders' Equity (Detail) $ / shares in Units, $ in Thousands		3 Months Ended
	May 15, 2019 USD ($) sales_agent	Jun. 30, 2019 USD ($) $ / shares shares
Class of Stock [Line Items]
Number of sales agents | sales_agent	9
At the Market Equity Distribution Agreement
Class of Stock [Line Items]
Aggregate offering price of common shares	$ 500,000
Shares, issued (in shares) | shares		930,000
Sale of Stock, Price Per Share | $ / shares		$ 107.61
Sale of Stock, Consideration Received on Transaction		$ 98,796
Value of stock available for issuance under ATM		$ 399,927