Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Additional Information (Detail)

v3.8.0.1
Fair Value Measurements - Additional Information (Detail) - Level 3 [Member]
9 Months Ended 12 Months Ended
Sep. 30, 2017
Dec. 31, 2016
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]    
Fair value interest rate spreads, minimum 1.00% 1.00%
Fair value interest rate spreads, maximum 4.00% 4.00%