Annual report pursuant to Section 13 and 15(d)

Contract Assets and Contract Liabilities - Narrative (Details)

v3.19.1
Contract Assets and Contract Liabilities - Narrative (Details) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Revenue from Contract with Customer [Abstract]    
Amounts billed but not yet paid pursuant to retention provisions $ 2.2 $ 3.3