Income Taxes (Statutory Tax Rate and Effective Tax Rate) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Taxes [Abstract]
Statutory federal tax	$ 14,815	$ 14,114	$ 9,493
State income taxes, net of federal benefit	769	446	797
Foreign Taxes	174	(77)	3
Domestic manufacturer deduction		(870)	(920)
Share-based compensation	(1,852)	(1,191)
Other permanent differences	615	147	41
Research and development and jobs credits	(85)		(163)
Effect of Federal tax law change		(222)
Other	323	258	36
Income Tax Expense (Benefit), Total	$ 14,759	$ 12,605	$ 9,287
Effective tax rate, Statutory federal tax	21.00%	35.00%	35.00%
Effective tax rate, State income taxes, net of federal benefit	1.10%	1.10%	2.90%
Effective Income Tax Rate Reconciliation, Foreign Taxes	0.30%	(0.20%)	0.00%
Effective tax rate, Domestic manufacturer deduction	(0.00%)	(2.20%)	(3.40%)
Effective tax rate, Share-based compensation	(2.60%)	(3.00%)	0.00%
Effective tax rate, Other permanent differences	0.80%	0.40%	0.20%
Effective tax rate, Research and development and jobs credits	(0.10%)	(0.00%)	(0.60%)
Effective tax rate, Effect of Federal tax law change	0.00%	(0.60%)	0.00%
Effective tax rate, Other	0.40%	0.80%	0.10%
Effective tax rate, Total	20.90%	31.30%	34.20%