Derivative Instruments	3 Months Ended
Mar. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	Derivative Instruments From time to time, we may enter into derivative financial instrument transactions to manage or reduce our market risk. We manage our debt portfolio to achieve an overall desired position of fixed and floating rates, and we may employ interest rate swaps as a tool to achieve that goal. We enter into foreign currency forward contracts and cross-currency swap contracts to economically hedge our exposure to fluctuations in various foreign currencies. The major risks from interest rate derivatives include changes in the interest rates affecting the fair value of such instruments, potential increases in interest expense due to market increases in floating interest rates, changes in foreign exchange rates and the creditworthiness of the counterparties in such transactions. We monitor the creditworthiness of our counterparties, which are multinational commercial banks. The fair values of all our outstanding derivative instruments are determined using a model with Level 2 inputs including quoted market prices for contracts with similar terms and maturity dates. Warrant During the fourth quarter of 2016, in conjunction with the issuance of 84.5 million ordinary shares, we issued a warrant that gives the holder the option to acquire an additional 84.5 million ordinary shares. The exercise price on the warrant is $6.43 per share and is exercisable any time prior to May 21, 2019. The warrant is carried at fair value on the Condensed Consolidated Balance Sheets and changes in the fair value are reported through earnings. The warrant participates in dividends and other distributions as if the shares subject to the warrants were outstanding. In addition, the warrant permits early redemption due to a change in control. The warrant fair value is considered a Level 2 valuation and is estimated using the Black Scholes valuation model. Inputs to the model include Weatherford’s share price, volatility of our share price, and the risk-free interest rate. The fair value of the warrant was zero at March 31, 2019 and December 31, 2018. We recognized an insignificant amount of unrealized gain in the first quarter of 2019 and unrealized gain of $46 million for the first quarter of 2018 with changes in fair value of the warrants recorded each period in “Warrant Fair Value Adjustment” on the accompanying Condensed Consolidated Statements of Operations. The insignificant change in fair value of the warrant during the first three months of 2019 was due to the short remaining time to maturity, low stock price, and the elimination of warrant share value associated with any future equity issuance. Foreign Currency Forward Contracts At March 31, 2019 and December 31, 2018, we had an estimated net current liability for the fair value of our outstanding foreign currency forward contracts of $1 million and $4 million, respectively, with notional amounts aggregating to $519 million and $435 million, respectively. These foreign currency forward contracts are not designated as hedges under ASU 2014-03, Derivatives and Hedging (Topic 815), and their notional amounts do not generally represent amounts exchanged by the parties and thus are not a measure of the cash requirements related to these contracts or of any possible loss exposure. The amounts actually exchanged at maturity are calculated by reference to the notional amounts and by other terms of the derivative contracts, such as exchange rates. The changes in fair value of the contracts are recorded each period in “Other Expense, Net” on the accompanying Condensed Consolidated Statements of Operations. For the quarter ended March 31, 2019 and March 31, 2018, we had a gain on the foreign currency forward contracts of $5 million and a gain of foreign currency forward contracts of $1 million, respectively. Other Derivative Instruments We may use interest rate swaps to help mitigate our exposures related to changes in the fair values of fixed-rate debt and to mitigate our exposure to variability in forecasted cash flows due to changes in interest rates. As of March 31, 2019, we did not have any fair value or cash flow hedges designated under ASU 2014-03. In 2008, we entered into interest rate derivative instruments to hedge projected exposures to interest rates in anticipation of a debt offering. These hedges were terminated at the time of the issuance of the debt and the associated loss is being amortized from “Accumulated Other Comprehensive Loss” to interest expense over the remaining term of the debt. See “Note 13 – Shareholders' (Deficiency) Equity” for additional information.

Derivative Instruments

From time to time, we may enter into derivative financial instrument transactions to manage or reduce our market risk. We manage our debt portfolio to achieve an overall desired position of fixed and floating rates, and we may employ interest rate swaps as a tool to achieve that goal. We enter into foreign currency forward contracts and cross-currency swap contracts to economically hedge our exposure to fluctuations in various foreign currencies. The major risks from interest rate derivatives include changes in the interest rates affecting the fair value of such instruments, potential increases in interest expense due to market increases in floating interest rates, changes in foreign exchange rates and the creditworthiness of the counterparties in such transactions.

We monitor the creditworthiness of our counterparties, which are multinational commercial banks. The fair values of all our outstanding derivative instruments are determined using a model with Level 2 inputs including quoted market prices for contracts with similar terms and maturity dates.

Warrant

During the fourth quarter of 2016, in conjunction with the issuance of 84.5 million ordinary shares, we issued a warrant that gives the holder the option to acquire an additional 84.5 million ordinary shares. The exercise price on the warrant is $6.43 per share and is exercisable any time prior to May 21, 2019. The warrant is carried at fair value on the Condensed Consolidated Balance Sheets and changes in the fair value are reported through earnings. The warrant participates in dividends and other distributions as if the shares subject to the warrants were outstanding. In addition, the warrant permits early redemption due to a change in control.

The warrant fair value is considered a Level 2 valuation and is estimated using the Black Scholes valuation model. Inputs to the model include Weatherford’s share price, volatility of our share price, and the risk-free interest rate. The fair value of the warrant was zero at March 31, 2019 and December 31, 2018. We recognized an insignificant amount of unrealized gain in the first quarter of 2019 and unrealized gain of $46 million for the first quarter of 2018 with changes in fair value of the warrants recorded each period in “Warrant Fair Value Adjustment” on the accompanying Condensed Consolidated Statements of Operations. The insignificant change in fair value of the warrant during the first three months of 2019 was due to the short remaining time to maturity, low stock price, and the elimination of warrant share value associated with any future equity issuance.

Foreign Currency Forward Contracts

At March 31, 2019 and December 31, 2018, we had an estimated net current liability for the fair value of our outstanding foreign currency forward contracts of $1 million and $4 million, respectively, with notional amounts aggregating to $519 million and $435 million, respectively. These foreign currency forward contracts are not designated as hedges under ASU 2014-03, Derivatives and Hedging (Topic 815), and their notional amounts do not generally represent amounts exchanged by the parties and thus are not a measure of the cash requirements related to these contracts or of any possible loss exposure. The amounts actually exchanged at maturity are calculated by reference to the notional amounts and by other terms of the derivative contracts, such as exchange rates.

The changes in fair value of the contracts are recorded each period in “Other Expense, Net” on the accompanying Condensed Consolidated Statements of Operations. For the quarter ended March 31, 2019 and March 31, 2018, we had a gain on the foreign currency forward contracts of $5 million and a gain of foreign currency forward contracts of $1 million, respectively.

Other Derivative Instruments

We may use interest rate swaps to help mitigate our exposures related to changes in the fair values of fixed-rate debt and to mitigate our exposure to variability in forecasted cash flows due to changes in interest rates. As of March 31, 2019, we did not have any fair value or cash flow hedges designated under ASU 2014-03. In 2008, we entered into interest rate derivative instruments to hedge projected exposures to interest rates in anticipation of a debt offering. These hedges were terminated at the time of the issuance of the debt and the associated loss is being amortized from “Accumulated Other Comprehensive Loss” to interest expense over the remaining term of the debt. See “Note 13 – Shareholders' (Deficiency) Equity” for additional information.