Basis and Summary of Significant Accounting Policies - Related Party Transactions (Details) - Related Party $ in Millions |
6 Months Ended | 36 Months Ended |
|---|---|---|
|
Jun. 30, 2018
USD ($)
lease
|
Dec. 31, 2004
Property
|
|
| Related Party Transaction [Line Items] | ||
| Sale leaseback, number of properties | Property | 21 | |
| Number of capital leases | 7 | |
| Number of operating leases | 10 | |
| Leases under renegotiation | 16 | |
| Capital leases, annual rental payments | $ | $ 0.4 | |
| Interest rate in the leases | 9.70% | |
| Operating leases, annual rental payments | $ | $ 0.8 |