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