Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=117329964&loc=d3e12355-112629

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=117329964&loc=d3e12317-112629

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585

Name:	us-gaap_GainsLossesOnExtinguishmentOfDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Long Term Debt - Term Loan Extinguishment of Debt (Details) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
	Jul. 02, 2020	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Extinguishment of Debt [Line Items]
Loss on extinguishment of debt		$ 8,200	$ 8,201	$ 0	$ 0
BT Loan Agreement
Extinguishment of Debt [Line Items]
Unamortized deferred financing costs	$ 4,528
Unamortized original issue discount	1,538
Unamortized amendment fee	671
Prepayment premium	1,439
Other fees	25
Loss on extinguishment of debt	$ 8,201