Net Income per Share - Schedule of Components Used in Diluted and Basic Income Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Numerator:
Net income (in dollars)	$ 123,146	$ 107,130
Denominator:
Shares used for basic net income per share (in shares)	161,992	163,236
Effect of dilutive securities:
Stock options (in shares)	11	49
RSUs and DSUs (in shares)	1,681	1,502
Convertible senior notes (in shares)	0	0
Warrants related to issuance of convertible senior notes (in shares)	0	0
Shares used for diluted net income per share (in shares)	163,684	164,787
Basic net income per share (in dollars per share)	$ 0.76	$ 0.66
Diluted net income per share (in dollars per share)	$ 0.75	$ 0.65