Investments (Cost Method Investments) (Details) $ in Billions |
3 Months Ended |
|---|---|
|
Mar. 31, 2017
USD ($)
preferred_stock_series
| |
| AirTouch [Member] | |
| Schedule of Cost-method Investments [Line Items] | |
| Number of Preferred Stock Series | preferred_stock_series | 2 |
| Level 2 [Member] | AirTouch [Member] | |
| Schedule of Cost-method Investments [Line Items] | |
| Fair Value Of Cost Method Investment Redeemable Preferred Shares | $ 1.8 |
| AirTouch [Member] | Level 2 [Member] | |
| Schedule of Cost-method Investments [Line Items] | |
| Fair value of redeemable preferred shares | $ 1.8 |