Income Taxes - Effective Income Tax Reconciliation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Jan. 01, 2017	Jan. 03, 2016
Income Taxes [Line Items]
Tax Cuts And Jobs Act Of 2017, Incomplete Accounting, Change In Tax Rate, Deferred Tax Asset, Income Tax Expense	$ 66.6
Federal statutory rate	(35.00%)	(35.00%)	(35.00%)
State income taxes, net of federal benefit	(4.50%)	2.50%	0.20%
Federal income tax credits, net	(1.20%)	(21.80%)	(7.60%)
Merger and litigation related costs	1.60%	5.80%	25.00%
Effective Income Tax Rate Reconciliation, Tax Settlement, Foreign, Percent	0.40%	2.40%	1.00%
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Percent	0.70%	1.80%	0.60%
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Percent	5.70%	(0.00%)	(0.00%)
Effective Income Tax Rate Reconciliation, Tax Reorganization, Percent	(7.60%)	(0.00%)	(0.00%)
State tax credit, valuation adjustment	2.00%	2.80%	(1.30%)
Other	1.90%	(0.20%)	(1.90%)
Effective income tax rate	(36.00%)	(41.70%)	(19.00%)
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent	(314.00%)	(0.00%)	(0.00%)
Effective Income Tax Rate Reconciliation, Adjusted, Percent	(350.00%)	(41.70%)	(19.00%)