Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2020	Mar. 31, 2020
Interest-bearing Notes [Member] | Prime Rate [Member]
Summary Of Significant Accounting Policy [Line Items]
Prime rate percentage	1.00%
Restricted Stock [Member]
Summary Of Significant Accounting Policy [Line Items]
Shares withheld to satisfy tax withholding obligations	99,785
Stock Repurchase Plan [Member]
Summary Of Significant Accounting Policy [Line Items]
Available authorized repurchase amount	$ 172,000,000.0
Stock repurchase plan expiration date	Mar. 12, 2022
Number of common stocks repurchased during the period	344,216
Stock repurchased, average costs per share	$ 227.00
Maximum [Member] | Stock Repurchase Plan [Member]
Summary Of Significant Accounting Policy [Line Items]
Stock repurchase plan, authorized amount		$ 250,000,000.0
Accounting Standards Update 2018-15 [Member]
Summary Of Significant Accounting Policy [Line Items]
Accounting standards update, adoption date	Jan. 01, 2020
Accounting standards update, adopted	true
Accounting standards update, immaterial effect	true
Accounting Standards Update 2018-13 [Member]
Summary Of Significant Accounting Policy [Line Items]
Accounting standards update, adoption date	Jan. 01, 2020
Accounting standards update, adopted	true
Accounting standards update, immaterial effect	true