Subsequent Events (Senior PIK notes, Holdings, USD $) In Thousands, unless otherwise specified	Apr. 30, 2013
Subsequent events
Amount of one-time principal prepayment	$ 129,800
Subsequent event
Subsequent events
Amount of one-time principal prepayment	$ 129,800

Represents the amount of one-time principal prepayment, which is the amount of previously capitalized payment-in-kind interest required to be paid to prevent the senior payment-in-kind notes from being treated as applicable high yield discount obligations.

No definition available.

Name:	gch_OneTimePrincipalPrepayment
Namespace Prefix:	gch_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant