Lease Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Thousands		6 Months Ended
	Jun. 28, 2019	Jun. 24, 2018	Sep. 29, 2019	Jun. 30, 2019	Dec. 31, 2018
Lessee, Lease, Description [Line Items]
Payments to acquire land	$ 150,300
Right-of-use asset		$ 0		$ 4,354	$ 0
Operating lease, liability				$ 4,133
Operating sublease, term				25 years
Operating lease, expense		$ 7,100
Galveston Land [Member] | Minimum [Member] | Scenario, Forecast [Member]
Lessee, Lease, Description [Line Items]
Right-of-use asset			$ 6,000
Operating lease, liability			4,000
Galveston Land [Member] | Maximum [Member] | Scenario, Forecast [Member]
Lessee, Lease, Description [Line Items]
Right-of-use asset			8,000
Operating lease, liability			$ 6,000