Income Taxes (Statutory Tax Rate and Effective Tax Rate) (Detail) - USD ($) $ in Thousands		12 Months Ended
	Dec. 21, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Taxes [Abstract]
Statutory federal tax		$ 19,396	$ 14,815	$ 14,114
State income taxes, net of federal benefit		864	769	446
Foreign Taxes		4	174	(77)
Domestic manufacturer deduction				(870)
Share-based compensation		(6,424)	(1,852)	(1,191)
Other permanent differences		1,004	615	147
Research and development and jobs credits		(579)	(85)
Effect of Federal tax law change				(222)
Other		182	323	258
Income Tax Expense (Benefit), Total		$ 14,447	$ 14,759	$ 12,605
Effective tax rate, Statutory federal tax	35.00%	21.00%	21.00%	35.00%
Effective tax rate, State income taxes, net of federal benefit		0.90%	1.10%	1.10%
Effective Income Tax Rate Reconciliation, Foreign Taxes		0.00%	0.30%	(0.20%)
Effective tax rate, Domestic manufacturer deduction		(0.00%)	(0.00%)	(2.20%)
Effective tax rate, Share-based compensation		(7.00%)	(2.60%)	(3.00%)
Effective tax rate, Other permanent differences		1.10%	0.80%	0.40%
Effective tax rate, Research and development and jobs credits		(0.60%)	(0.10%)	(0.00%)
Effective tax rate, Effect of Federal tax law change		0.00%	0.00%	(0.60%)
Effective tax rate, Other		0.20%	0.40%	0.80%
Effective tax rate, Total		15.60%	20.90%	31.30%