SUPPLEMENTAL EXECUTIVE RETIREMENT PLANS (Details) - Defined Contribution Supplemental Executive Retirement Plan - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
SUPPLEMENTAL EXECUTIVE RETIREMENT PLANS
Estimated accumulated benefit obligation	$ 3.1	$ 3.0
Funded estimated accumulated benefit obligation	3.0	2.4
Unfunded estimated accumulated benefit obligation	$ 0.1	$ 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