Commitments and Contingencies - Narrative (Details) € in Millions, $ in Millions, kr in Billions	Dec. 31, 2018 USD ($)	Dec. 31, 2018 SEK (kr)	Dec. 31, 2017 USD ($)	Dec. 31, 2017 EUR (€)
Credit Agreement, Seventh Amendment
Loss Contingencies [Line Items]
Amount of letters of credit that can be issued under the Revolver	$ 50
Swedish Tax Agency
Loss Contingencies [Line Items]
Total assessment, including penalties and interest, not recorded	$ 400	kr 3.5
French Tax Authority
Loss Contingencies [Line Items]
Total assessment, including penalties and interest, not recorded			$ 652	€ 571