Condensed Consolidated Statements of Changes in Stockholder's Equity - USD ($) $ in Thousands	Total	Common Stock	Additional  Paid-in Capital	Accumulated Other Comprehensive Earnings (Loss)	Retained Earnings
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	3,988		3,988
Issuance of common stock in connection with the Company’s equity award plans (in shares)		3,811
Issuance of common stock in connection with the Company’s equity award plans	32		32
Net earnings	21,518				21,518
Unrealized loss on marketable securities, net of tax	(7,583)			(7,583)
Balance (in shares) at Mar. 31, 2020		52,537,159
Balance at Mar. 31, 2020	613,383	$ 53	392,430	(166)	221,066
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
Net earnings	56,185
Unrealized loss on marketable securities, net of tax	3,942
Balance (in shares) at Jun. 30, 2020		52,624,084
Balance at Jun. 30, 2020	665,974	$ 53	398,829	11,359	255,733
Balance (in shares) at Mar. 31, 2020		52,537,159
Balance at Mar. 31, 2020	613,383	$ 53	392,430	(166)	221,066
Increase (Decrease) in Stockholders' Equity
Share-based compensation	4,962		4,962
Issuance of common stock in connection with the Company’s equity award plans (in shares)		86,925
Issuance of common stock in connection with the Company’s equity award plans	1,437		1,437
Net earnings	34,667				34,667
Unrealized loss on marketable securities, net of tax	11,525			11,525
Balance (in shares) at Jun. 30, 2020		52,624,084
Balance at Jun. 30, 2020	665,974	$ 53	398,829	11,359	255,733
Balance (in shares) at Dec. 31, 2020		52,868,482
Balance at Dec. 31, 2020	744,858	$ 53	409,332	8,975	326,498
Increase (Decrease) in Stockholders' Equity
Share-based compensation	4,371		4,371
Issuance of common stock in connection with the Company’s equity award plans (in shares)		125,655
Issuance of common stock in connection with the Company’s equity award plans	2,247		2,247
Net earnings	5,694				5,694
Unrealized loss on marketable securities, net of tax	(2,726)			(2,726)
Balance (in shares) at Mar. 31, 2021		52,994,137
Balance at Mar. 31, 2021	754,444	$ 53	415,950	6,249	332,192
Balance (in shares) at Dec. 31, 2020		52,868,482
Balance at Dec. 31, 2020	744,858	$ 53	409,332	8,975	326,498
Increase (Decrease) in Stockholders' Equity
Net earnings	29,420
Unrealized loss on marketable securities, net of tax	(3,542)
Balance (in shares) at Jun. 30, 2021		53,144,759
Balance at Jun. 30, 2021	785,579	$ 53	424,175	5,433	355,918
Balance (in shares) at Mar. 31, 2021		52,994,137
Balance at Mar. 31, 2021	754,444	$ 53	415,950	6,249	332,192
Increase (Decrease) in Stockholders' Equity
Share-based compensation	5,476		5,476
Issuance of common stock in connection with the Company’s equity award plans (in shares)		150,622
Issuance of common stock in connection with the Company’s equity award plans	2,749		2,749
Net earnings	23,726				23,726
Unrealized loss on marketable securities, net of tax	(816)			(816)
Balance (in shares) at Jun. 30, 2021		53,144,759
Balance at Jun. 30, 2021	$ 785,579	$ 53	$ 424,175	$ 5,433	$ 355,918