Lease Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Thousands		9 Months Ended
	Jun. 28, 2019	Sep. 23, 2018	Sep. 29, 2019	Dec. 31, 2018
Lessee, Lease, Description [Line Items]
Payments to acquire land	$ 150,300
Right-of-use asset		$ 0	$ 11,067	$ 0
Operating lease, liability			$ 9,366
Operating sublease, term			25 years
Operating lease, expense		$ 11,700
Galveston Land [Member]
Lessee, Lease, Description [Line Items]
Right-of-use asset			$ 6,800
Operating lease, liability			$ 5,300