Income Taxes (Reconciliation of U.S. Statutory Income Tax Rate) (Details)	4 Months Ended	8 Months Ended	12 Months Ended
	Dec. 31, 2017	Aug. 25, 2018	Aug. 25, 2018		Aug. 26, 2017	Aug. 27, 2016
Income Tax Disclosure [Abstract]
U.S. federal statutory rate	35.00%	21.00%	25.90%	[1]	35.00%	35.00%
State taxes, net of federal benefit			3.00%		2.80%	2.50%
Tax-free and dividend income			(0.40%)		(0.70%)	(1.30%)
Income tax credits			(0.50%)		(0.60%)	(1.10%)
Domestic production activities deduction			(2.20%)		(2.40%)	(2.50%)
Uncertain tax positions settlements and adjustments			0.10%		(0.60%)	0.00%
Impact from Tax Act			2.60%		0.00%	0.00%
Other items			(0.30%)		0.80%	(1.30%)
Effective tax provision rate			28.20%		34.30%	31.30%

[1] The U.S. federal statutory rate for the year ended August 25, 2018 is a blended rate, which includes the impact of the Tax Act enactment.