Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($) segment	Dec. 31, 2019 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of operating segments | segment	1
Offered period for sales return	30 days
Allowance for product returns	$ 500	$ 400
Warranty reserve	16,761	$ 16,724
Warranty reserves
Summary Of Significant Accounting Policies [Line Items]
Warranty reserve	$ 16,761
Complementary products
Summary Of Significant Accounting Policies [Line Items]
Warranty period offered	4 years
Tandem Pump
Summary Of Significant Accounting Policies [Line Items]
Warranty period offered	4 years
Slim cartridges and infusion sets
Summary Of Significant Accounting Policies [Line Items]
Warranty period offered	6 months