Debt - Redemption Rates (Detail) - Senior Notes - 2025 Notes	12 Months Ended
	Dec. 31, 2019
Debt instrument redemption period one
Debt Instrument [Line Items]
Percentage of debt redemption price	102.625%
Debt instrument redemption period two
Debt Instrument [Line Items]
Percentage of debt redemption price	101.75%
Debt instrument redemption period three
Debt Instrument [Line Items]
Percentage of debt redemption price	100.875%
Debt instrument redemption period four and thereafter
Debt Instrument [Line Items]
Percentage of debt redemption price	100.00%