Revenue - Schedule of Contract Assets and Liabilities (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Contract assets	$ 38,400,000	$ 36,500,000
Contract liabilities	32,900,000	32,800,000
Net contract assets	5,500,000	$ 3,700,000
$ Change
Contract assets	1,900,000
Contract liabilities	100,000
Net contract assets	$ 1,800,000
% Change
Contract assets	5.20%
Contract liabilities	0.30%
Net contract assets	48.60%
Percent of contract liabilities	50.00%
Impairment losses on contract assets	$ 0