Quarterly report pursuant to Section 13 or 15(d)

Income Taxes - Additional Information (Detail)

v3.8.0.1
Income Taxes - Additional Information (Detail)
3 Months Ended
Mar. 31, 2018
USD ($)
Income Tax Contingency [Line Items]  
Adjustments to provisional amounts due to Tax Act $ 0
Tax cuts and jobs act of 2017, accounting complete false
Internal Revenue Service [Member] | Earliest Tax Year [Member]  
Income Tax Contingency [Line Items]  
Open tax year 2011
Internal Revenue Service [Member] | Latest Tax Year [Member]  
Income Tax Contingency [Line Items]  
Open tax year 2014