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 12 Months Ended
Mar. 31, 2018
Dec. 31, 2017
Income Tax Disclosure [Abstract]    
U.S. corporate tax rate 21.00% 35.00%