Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Summary of Fair Value and Carrying Value of Financial Assets and Liabilities (Parenthetical) (Detail)

v3.8.0.1
Fair Value Measurements - Summary of Fair Value and Carrying Value of Financial Assets and Liabilities (Parenthetical) (Detail) - USD ($)
9 Months Ended 12 Months Ended
Sep. 30, 2017
Dec. 31, 2016
Fair Value Disclosures [Abstract]    
Financing receivables held for sale $ 0 $ 0
Amortized cost $ 131,000,000 $ 61,000,000