Employee Benefits - DC SERP (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Employee Benefits
Estimated accumulated benefit obligation	$ 3.9	$ 3.0
Funded estimated accumulated benefit obligation	3.3	2.4
Unfunded estimated accumulated benefit obligation	$ 0.6	$ 0.6

The amount of unfunded estimated accumulated obligation benefit under the defined contribution plan.

No definition available.

Name:	hgr_DefinedContributionPlanEstimatedAccumulatedObligationBenefitUnfunded
Namespace Prefix:	hgr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant