XML 106 R60.htm IDEA: XBRL DOCUMENT v3.8.0.1
Income Taxes - Reconciliation of Statutory Federal Tax Rate to Effective Income Tax Rate (Detail)
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Income Tax Disclosure [Abstract]      
Federal statutory tax rate 35.00% 35.00% 35.00%
State income taxes, net of Federal income tax benefit 4.00% 4.00% 4.00%
Nondeductible expenses 1.00% 1.00% 3.00%
Research credit, Federal benefit (3.00%) (2.00%) (1.00%)
Section 199 - Qualified production activities (2.00%) (2.00%) (3.00%)
Stock-based compensation (21.00%) (12.00%) (0.00%)
Return to provision (1.00%) (0.00%) (0.00%)
Remeasurement of deferred tax assets 1.00% 0.00% 0.00%
Other (1.00%) (1.00%) 0.00%
Effective income tax rate 13.00% 23.00% 38.00%