XML 19 R55.htm IDEA: XBRL DOCUMENT v3.20.1
Fair Value Measurements - Additional Information (Detail) - USD ($)
$ in Billions
Mar. 31, 2020
Dec. 31, 2019
Fair Value, Inputs, Level 2 [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Debt obligations, fair value $ 1.5 $ 1.6