Organization Organization (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	Oct. 11, 2017	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2017
Organization [Line Items]
Sale of Stock, Number of Shares Issued in Transaction	4,700
Payments of Stock Issuance Costs	$ 4.9
Class A
Organization [Line Items]
Common Stock, Shares, Outstanding		55,218		35,938
IPO [Member]
Organization [Line Items]
Sale of Stock, Consideration Received on Transaction	$ 577.3
IPO [Member] | Class A
Organization [Line Items]
Sale of Stock, Number of Shares Issued in Transaction	35,900
Sale of Stock, Price Per Share	$ 17.00
Switch, Ltd.
Organization [Line Items]
Sale of Stock, Number of Shares Issued in Transaction	35,900
Rob Roy and Affiliated Entity [Member]
Organization [Line Items]
Percentage Voting Interests of Shareholder	67.20%	67.90%
Continuing Members [Member]
Organization [Line Items]
Percentage Voting Interests of Shareholder	94.40%
Continuing Members [Member] | Shares of Class B and Class C Common Stock
Organization [Line Items]
Common Stock, Shares, Outstanding	216,600
Switch, Ltd.
Organization [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent			22.70%	14.50%