Condensed Consolidated Statements Of Changes In Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Treasury Stock, at Cost	Accumulated Other Comprehensive Income (Loss)	Retained Earnings
Beginning balance (in shares) at Dec. 31, 2018		57,494,468
Beginning balance at Dec. 31, 2018	$ 779,477	$ 57	$ 648,651	$ 0	$ (62,355)	$ 193,124
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	12,339		12,339
Issuance of common stock under the Equity Incentive Plan (in shares)		554,758
Issuance of common stock under the Equity Incentive Plan	21,184	$ 1	21,183
Shares received in net share settlement of stock option exercises and vesting of restricted stock (in shares)		(51,658)
Shares received in net share settlement of stock option exercises and vesting of restricted stock	(6,531)		(6,531)
Purchase of treasury stock	(12,415)			(12,415)
Retirement of treasury stock (in shares)		(80,001)
Retirement of treasury stock	0	$ 0	(12,415)	12,415
Other comprehensive income (loss)	(32,182)				(32,182)
Net income (loss)	132,623					132,623
Ending balance (in shares) at Sep. 30, 2019		57,917,567
Ending balance at Sep. 30, 2019	894,495	$ 58	663,227	0	(94,537)	325,747
Beginning balance (in shares) at Jun. 30, 2019		57,898,902
Beginning balance at Jun. 30, 2019	878,362	$ 58	667,154	0	(73,343)	284,493
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	4,721		4,721
Issuance of common stock under the Equity Incentive Plan (in shares)		100,462
Issuance of common stock under the Equity Incentive Plan	4,128		4,128
Shares received in net share settlement of stock option exercises and vesting of restricted stock (in shares)		(6,296)
Shares received in net share settlement of stock option exercises and vesting of restricted stock	(991)		(991)
Purchase of treasury stock	(11,785)			(11,785)
Retirement of treasury stock (in shares)		(75,501)
Retirement of treasury stock	0		(11,785)	11,785
Other comprehensive income (loss)	(21,194)				(21,194)
Net income (loss)	41,254					41,254
Ending balance (in shares) at Sep. 30, 2019		57,917,567
Ending balance at Sep. 30, 2019	894,495	$ 58	663,227	0	(94,537)	325,747
Beginning balance (in shares) at Dec. 31, 2019		57,884,020
Beginning balance at Dec. 31, 2019	971,268	$ 58	648,031	0	(50,331)	373,510
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock (in shares)		2,138,580
Issuance of common stock	249,790	$ 2	249,788
Stock-based compensation expense	15,138		15,138
Issuance of common stock under the Equity Incentive Plan (in shares)		535,930
Issuance of common stock under the Equity Incentive Plan	24,113	$ 1	24,112
Shares received in net share settlement of stock option exercises and vesting of restricted stock (in shares)		(64,048)
Shares received in net share settlement of stock option exercises and vesting of restricted stock	(8,896)		(8,896)
Purchase of treasury stock	(32,208)			(32,208)
Retirement of treasury stock (in shares)		(231,313)
Retirement of treasury stock	0	$ (1)	(32,207)	32,208
Other comprehensive income (loss)	(16,529)				(16,529)
Net income (loss)	24,437					24,437
Ending balance (in shares) at Sep. 30, 2020		60,263,169
Ending balance at Sep. 30, 2020	1,227,113	$ 60	895,966	0	(66,860)	397,947
Beginning balance (in shares) at Jun. 30, 2020		60,152,187
Beginning balance at Jun. 30, 2020	1,198,275	$ 60	885,373	0	(91,759)	404,601
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	5,700		5,700
Issuance of common stock under the Equity Incentive Plan (in shares)		119,778
Issuance of common stock under the Equity Incentive Plan	6,074		6,074
Shares received in net share settlement of stock option exercises and vesting of restricted stock (in shares)		(8,796)
Shares received in net share settlement of stock option exercises and vesting of restricted stock	(1,181)		(1,181)
Other comprehensive income (loss)	24,899				24,899
Net income (loss)	(6,654)					(6,654)
Ending balance (in shares) at Sep. 30, 2020		60,263,169
Ending balance at Sep. 30, 2020	$ 1,227,113	$ 60	$ 895,966	$ 0	$ (66,860)	$ 397,947