Commitments and Contingencies - Schedule of Contributions made to Multiemployer Plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Multiemployer Plans [Line Items]
Contributions	$ 13,514	$ 12,442	$ 11,977
Pension Plans
Multiemployer Plans [Line Items]
Contributions	3,327	3,035	3,155
Pension Plans | Multiemployer Plan, Individually Insignificant Multiemployer Plans
Multiemployer Plans [Line Items]
Contributions	1,000	900	800
Health Plans
Multiemployer Plans [Line Items]
Contributions	9,373	8,551	8,280
Health Plans | Multiemployer Plan, Individually Insignificant Multiemployer Plans
Multiemployer Plans [Line Items]
Contributions	1,600	1,600	1,600
Other
Multiemployer Plans [Line Items]
Contributions	814	856	542
Other | Multiemployer Plan, Individually Insignificant Multiemployer Plans
Multiemployer Plans [Line Items]
Contributions	$ 200	$ 200	$ 200