Restatement of 2018 Condensed Consolidated Financial Statements - Impact of Corrections on Statement of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 29, 2019	Dec. 30, 2018	Sep. 30, 2018	Sep. 29, 2019	Sep. 30, 2018	Dec. 30, 2018
Operating activities
Net income before attribution to noncontrolling interests	$ 257	$ (13,225)	$ (12,861)	$ 7,335	$ 17,298	$ 4,073
Changes in operating assets and liabilities:
Deferred income taxes				(2,386)	(227)	1,620
Accounts receivable				(8,156)	11,083	4,245
Income tax receivable				10,241	(7,423)	(12,157)
Prepaid expenses				11,926	8,097	(1,039)
Other current assets				(17,289)	3,534
Other assets and liabilities				(3,245)	(4,910)
Accounts payable				14,921	2,101	(400)
Income and other taxes payable				1,285	(1,597)
Accrued expenses and other current liabilities				(19,149)	23,105	25,177
Deferred revenue				(4,061)	(1,860)	(1,551)
Net cash provided by operating activities				49,999	105,032	92,454
Financing activities
Net (repayments) proceeds of revolving credit facility				(236,966)	121,476	163,585
Net cash used in financing activities				(30,674)	(75,968)	(48,097)
Change in cash and cash equivalents				(4,890)	6,631	5,367
Cash and cash equivalents at beginning of period		34,522		33,258	27,891	27,891
Cash and cash equivalents at end of period	$ 28,368	33,258	34,522	28,368	34,522	33,258
As reported
Operating activities
Net income before attribution to noncontrolling interests		(14,206)	(12,594)		17,451	3,245
Changes in operating assets and liabilities:
Deferred income taxes						1,705
Accounts receivable					7,410	1,386
Income tax receivable					(7,373)	(12,170)
Prepaid expenses					7,663	(2,165)
Other current assets					5,016
Other assets and liabilities					(4,899)
Accounts payable					769	(1,694)
Accrued expenses and other current liabilities					18,772	10,273
Deferred revenue					(4)	(271)
Net cash provided by operating activities					98,812	72,795
Financing activities
Net (repayments) proceeds of revolving credit facility					123,600	175,000
Net cash used in financing activities					(73,844)	(36,682)
Change in cash and cash equivalents					2,535	(2,877)
Cash and cash equivalents at beginning of period		24,880		19,468	22,345	22,345
Cash and cash equivalents at end of period		19,468	24,880		24,880	19,468
Total Adjustments
Operating activities
Net income before attribution to noncontrolling interests		981	(267)		(153)	828
Changes in operating assets and liabilities:
Deferred income taxes						(85)
Accounts receivable					3,673	2,859
Income tax receivable					(50)	13
Prepaid expenses					434	1,126
Other current assets					(1,482)
Other assets and liabilities					(11)
Accounts payable					1,332	1,294
Accrued expenses and other current liabilities					4,333	14,904
Deferred revenue					(1,856)	(1,280)
Net cash provided by operating activities					6,220	19,659
Financing activities
Net (repayments) proceeds of revolving credit facility					(2,124)	(11,415)
Net cash used in financing activities					(2,124)	(11,415)
Change in cash and cash equivalents					4,096	8,244
Cash and cash equivalents at beginning of period		9,642		$ 13,790	5,546	5,546
Cash and cash equivalents at end of period		$ 13,790	$ 9,642		$ 9,642	$ 13,790