Stock-based Compensation - Other than Options (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Skyhook \| LTIPs \| PARs and PSUs \| Other liabilities \| Level 2
Stock Based Compensation
Deferred compensation	$ 1.0	$ 1.2

Aggregate carrying value as of the balance sheet date of the liabilities for stock option plans and other equity-based compensation arrangements payable after one year (or the operating cycle, if longer).

No definition available.

Name:	us-gaap_DeferredCompensationSharebasedArrangementsLiabilityClassifiedNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant