Shareholders' Equity - Noncontrolling Interests (Details) - SACS |
12 Months Ended |
---|---|
Dec. 31, 2017 | |
Noncontrolling Interest [Line Items] | |
Life term of contract | 25 years |
Percentage of profit share of parent in joint venture | 88.75% |
Percentage of profit share of noncontrolling in joint venture | 11.25% |