Earnings Per Share - Reconciliation of Basic and Diluted Shares Amounts (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Numerator
Net income	$ 46,964	$ 29,450
Effect of dilutive securities
Charges associated with convertible debt instruments, net of tax	387	0
Numerator for diluted earnings per share - net income available to common stockholders after the effect of dilutive securities	$ 29,450	$ 47,351
Denominator
Weighted average shares used in computing net income per share - basic	55,353	54,805
Effect of dilutive shares
Options and stock units	726	964
Convertible senior notes	2,726	1,092
Dilutive effect of unvested performance stock units	11	8
Dilutive potential common shares	3,463	2,064
Denominator for diluted earnings per share - adjusted weighted average shares used in computing net income per share - diluted	58,816	56,869
Earnings per share:
Basic	$ 0.85	$ 0.54
Diluted	$ 0.81	$ 0.52