Basis and Summary of Significant Accounting Policies - Supplemental Disclosure of Noncash Investing Transactions (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Accounting Policies [Abstract]
Asset acquisition, fair value of non-cash consideration	$ 0.6
Asset acquisition, non-cash settlement of accounts receivable		$ 0.3	$ 0.4