Restatement of 2018 Condensed Consolidated Financial Statements - Impact of Corrections on Condensed Consolidated Balance Sheet (Details) - USD ($) $ in Thousands	Sep. 29, 2019	Jun. 30, 2019	Dec. 31, 2018	Dec. 30, 2018	Sep. 30, 2018	Jul. 01, 2018	Dec. 31, 2017
Percentage of domestic restaurants franchised	80.00%
Assets
Cash and cash equivalents	$ 28,368			$ 33,258
Accounts receivable, net	82,401			78,118
Income tax receivable	5,905			16,146
Prepaid expenses	18,450		$ 25,707	30,376
Other current assets	21,125			5,678
Total current assets	194,384			196,277
Deferred income taxes, net	1,197			1,137
Total assets	730,565			595,897
Current liabilities:
Accounts payable	42,027			27,106
Accrued expenses and other current liabilities	115,026			129,167
Current deferred revenue	2,461			2,598
Current portion of long-term debt	29,051			20,009
Total current liabilities	221,889			185,470
Deferred revenue	16,671			20,674
Total liabilities	800,009			894,446
Retained earnings	218,524			242,182
Total stockholders' equity (deficit)	(326,366)	$ (318,066)		(304,013)	$ (277,706)	$ (253,111)	$ (105,954)
Total liabilities, Series B Convertible Preferred Stock, Redeemable noncontrolling interests and Stockholders' (deficit)	$ 730,565			595,897
As reported
Assets
Cash and cash equivalents				19,468
Accounts receivable, net				67,854
Income tax receivable				16,073
Prepaid expenses				29,935
Other current assets				5,677
Total current assets				171,708
Deferred income taxes, net				756
Total assets				570,947
Current liabilities:
Accounts payable				29,891
Accrued expenses and other current liabilities				105,712
Current deferred revenue				2,443
Current portion of long-term debt				20,000
Total current liabilities				164,636
Deferred revenue				14,679
Total liabilities				867,617
Retained earnings				244,061
Total stockholders' equity (deficit)				(302,134)
Total liabilities, Series B Convertible Preferred Stock, Redeemable noncontrolling interests and Stockholders' (deficit)				570,947
Total Adjustments
Assets
Cash and cash equivalents				13,790
Accounts receivable, net				10,264
Income tax receivable				73
Prepaid expenses				441
Other current assets				1
Total current assets				24,569
Deferred income taxes, net				381
Total assets				24,950
Current liabilities:
Accounts payable				(2,785)
Accrued expenses and other current liabilities				23,455
Current deferred revenue				155
Current portion of long-term debt				9
Total current liabilities				20,834
Deferred revenue				5,995
Total liabilities				26,829
Retained earnings				(1,879)
Total stockholders' equity (deficit)				(1,879)
Total liabilities, Series B Convertible Preferred Stock, Redeemable noncontrolling interests and Stockholders' (deficit)				$ 24,950