Business, Basis of Presentation and Significant Accounting Policies (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) segment	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Business, Basis Of Presentation And Significant Accounting Policies [Line Items]
Number of reportable segments | segment	5
Valuation allowances for inventory	$ 7,700	$ 7,800
Cash	71,427	27,422	$ 40,326	$ 38,767
Financing costs incurred	5,500
Amortization of deferred financing costs	2,900	2,900	$ 3,300
Deferred financing costs, net of accumulated amortization	12,400	10,100
Self-Insurance [Member] | Workers' Compensation Policy [Member]
Business, Basis Of Presentation And Significant Accounting Policies [Line Items]
Per claim deductible, insurance policies	1,800
Self-Insurance [Member] | General Liability Policy [Member]
Business, Basis Of Presentation And Significant Accounting Policies [Line Items]
Per claim deductible, insurance policies	3,000
Self-Insurance [Member] | Property Insurance Policy [Member] | Automobile Liability [Member]
Business, Basis Of Presentation And Significant Accounting Policies [Line Items]
Per claim deductible, insurance policies	8,000
Self-Insurance [Member] | Employee Group Medical Claims Policy [Member]
Business, Basis Of Presentation And Significant Accounting Policies [Line Items]
Loss contingency, maximum loss per employee	500
Proportionately Consolidated Non-Controlled Joint Venture [Member]
Business, Basis Of Presentation And Significant Accounting Policies [Line Items]
Cash	$ 13,100	$ 11,800
Maximum [Member]
Business, Basis Of Presentation And Significant Accounting Policies [Line Items]
Lessee, Lease, Term Of Contract	10 years
Facility Leases [Member] | Minimum [Member]
Business, Basis Of Presentation And Significant Accounting Policies [Line Items]
Lessee, Lease, Renewal Term	1 year
Facility Leases [Member] | Maximum [Member]
Business, Basis Of Presentation And Significant Accounting Policies [Line Items]
Lessee, Lease, Renewal Term	5 years
Equipment Leases [Member] | Minimum [Member]
Business, Basis Of Presentation And Significant Accounting Policies [Line Items]
Lessee, Lease, Renewal Term	1 year
Equipment Leases [Member] | Maximum [Member]
Business, Basis Of Presentation And Significant Accounting Policies [Line Items]
Lessee, Lease, Renewal Term	5 years