Variable Interest Entities ("VIEs") - Narrative (Details) - USD ($) $ in Millions |
1 Months Ended | 12 Months Ended | |||
|---|---|---|---|---|---|
Jul. 02, 2019 |
Apr. 30, 2019 |
Mar. 31, 2018 |
Dec. 31, 2019 |
Dec. 31, 2018 |
|
| Variable Interest Entity [Line Items] | |||||
| Limited guarantee | $ 50 | $ 50 | |||
| Variable Interest Entity, Primary Beneficiary | |||||
| Variable Interest Entity [Line Items] | |||||
| Assets | 1,200 | $ 115 | |||
| Liabilities | $ 159 | ||||
| Percentage of ownership before sale of stock | 100.00% | ||||
| Variable Interest Entity, Not Primary Beneficiary | Event Center Office Partners, LLC | |||||
| Variable Interest Entity [Line Items] | |||||
| Payments to acquire variable interest entity | $ 136 | ||||
| Ownership interest | 45.00% | 45.00% | 45.00% | ||
| Limited guarantee | $ 50 | ||||
| Preferred Class A | ATG Investment | |||||
| Variable Interest Entity [Line Items] | |||||
| Percentage of ownership after sale of stock | 13.80% | ||||