Consolidated Statements of Stockholders' Equity (Parenthetical) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019 USD ($)	Sep. 30, 2019 USD ($)
Statement Of Stockholders Equity [Abstract]
Equity component of convertible senior notes, Deferred tax	$ 14,819	$ 14,819
Equity component of convertible senior notes, issuance cost	1,700	1,700
Purchase of note hedge related to convertible senior notes, deferred tax	$ 16,047	$ 16,047