Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, Adjusted Balance	Common Stock	Common Stock Cumulative Effect, Period of Adoption, Adjusted Balance	Additional Paid-in Capital	Additional Paid-in Capital Cumulative Effect, Period of Adoption, Adjustment	Additional Paid-in Capital Cumulative Effect, Period of Adoption, Adjusted Balance	Accumulated Other Comprehensive Earnings (Loss)	Accumulated Other Comprehensive Earnings (Loss) Cumulative Effect, Period of Adoption, Adjusted Balance	Retained Earnings (Accumulated Deficit)	Retained Earnings (Accumulated Deficit) Cumulative Effect, Period of Adoption, Adjustment	Retained Earnings (Accumulated Deficit) Cumulative Effect, Period of Adoption, Adjusted Balance
Balance (in shares) at Dec. 31, 2017				51,314,850	51,314,850
Balance at Dec. 31, 2017	$ 267,480	$ 2,322	$ 269,802	$ 51	$ 51	$ 294,999	$ 0	$ 294,999	$ (747)	$ (747)	$ (26,823)	$ 2,322	$ (24,501)
Increase (Decrease) in Stockholders' Equity
Share-based compensation	11,291					11,291
Issuance of common stock in connection with the Company’s equity award plans (in shares)				1,001,733
Issuance of common stock in connection with the Company’s equity award plans	11,582			$ 1		11,581
Equity issued on conversion of convertible notes	56,215					56,215
Purchase of convertible note hedges, net of tax	(70,137)					(70,137)
Issuance of warrants	65,688					65,688
Net earnings	110,993										110,993
Unrealized gain (loss) on marketable securities, net of tax	(2,411)								(2,411)
Balance (in shares) at Dec. 31, 2018				52,316,583
Balance at Dec. 31, 2018	453,023			$ 52		369,637			(3,158)		86,492
Increase (Decrease) in Stockholders' Equity
Share-based compensation	14,846					14,846
Issuance of common stock in connection with the Company’s equity award plans (in shares)				216,765
Issuance of common stock in connection with the Company’s equity award plans	3,928			$ 1		3,927
Net earnings	113,056										113,056
Unrealized gain (loss) on marketable securities, net of tax	10,575								10,575
Balance (in shares) at Dec. 31, 2019				52,533,348
Balance at Dec. 31, 2019	595,428			$ 53		388,410			7,417		199,548
Increase (Decrease) in Stockholders' Equity
Share-based compensation	16,561					16,561
Issuance of common stock in connection with the Company’s equity award plans (in shares)				335,134
Issuance of common stock in connection with the Company’s equity award plans	4,361					4,361
Net earnings	126,950
Unrealized gain (loss) on marketable securities, net of tax	1,558								1,558
Balance (in shares) at Dec. 31, 2020				52,868,482
Balance at Dec. 31, 2020	$ 744,858			$ 53		$ 409,332			$ 8,975		$ 326,498