Consolidated Statements of Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Total
Balance (in shares) at Dec. 31, 2018	26,984,747
Balance at Dec. 31, 2018	$ 27	$ 258,502	$ 291,460	$ (8,492)	$ 541,497
Common shares issued on exercise of options and other, net of shares withheld for tax obligations (in shares)	19,950
Common shares issued on exercise of options and other, net of shares withheld for tax obligations	$ 0	(420)	0	0	(420)
Stock-based compensation expense	$ 0	3,040	0	0	3,040
Repurchases of common stock (in shares)	(157,716)
Repurchases of common stock	$ 0	(1,511)	(15,798)	0	(17,309)
Net income	0	0	15,511	0	15,511
Other comprehensive income
Foreign currency translation adjustment	$ 0	0	0	476	476
Comprehensive income					15,987
Balance (in shares) at Dec. 31, 2018	26,984,747
Balance at Dec. 31, 2018	$ 27	258,502	291,460	(8,492)	541,497
Other comprehensive income
Common shares issued on exercise of options and other, net of shares withheld for tax obligations (in shares)	19,950
Common shares issued on exercise of options and other, net of shares withheld for tax obligations	$ 0	(420)	0	0	(420)
Stock-based compensation expense	$ 0	3,040	0	0	3,040
Repurchases of common stock (in shares)	(157,716)
Repurchases of common stock	$ 0	(1,511)	(15,798)	0	(17,309)
Net income	$ 0	0	15,511	0	15,511
Balance (in shares) at Mar. 31, 2019	26,846,981
Balance at Mar. 31, 2019	$ 27	259,611	291,173	(8,016)	$ 542,795
Balance (in shares) at Dec. 31, 2019	26,786,459				26,786,459
Balance at Dec. 31, 2019	$ 27	268,059	324,722	(7,018)	$ 585,790
Common shares issued on exercise of options and other, net of shares withheld for tax obligations (in shares)	23,525
Common shares issued on exercise of options and other, net of shares withheld for tax obligations	$ 0	(902)	0	0	(902)
Stock-based compensation expense	$ 0	3,033	0	0	3,033
Repurchases of common stock (in shares)	(161,460)
Repurchases of common stock	$ 0	(1,616)	(9,569)	0	(11,185)
Net income	0	0	13,984	0	13,984
Other comprehensive income
Foreign currency translation adjustment	$ 0	0	0	(2,980)	(2,980)
Comprehensive income					$ 11,004
Balance (in shares) at Dec. 31, 2019	26,786,459				26,786,459
Balance at Dec. 31, 2019	$ 27	268,059	324,722	(7,018)	$ 585,790
Other comprehensive income
Common shares issued on exercise of options and other, net of shares withheld for tax obligations (in shares)	23,525
Common shares issued on exercise of options and other, net of shares withheld for tax obligations	$ 0	(902)	0	0	(902)
Stock-based compensation expense	$ 0	3,033	0	0	3,033
Repurchases of common stock (in shares)	(161,460)
Repurchases of common stock	$ 0	(1,616)	(9,569)	0	(11,185)
Net income	$ 0	0	13,984	0	$ 13,984
Balance (in shares) at Mar. 31, 2020	26,648,524				26,648,524
Balance at Mar. 31, 2020	$ 27	$ 268,574	$ 329,137	$ (9,998)	$ 587,740