Long-term Compensation Plans - Equity Classified Share Based Payments Narrative (Details) - shares	12 Months Ended
	Dec. 31, 2017	Jun. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total number of shares of common stock that may be subject to grant awards (in shares)		15,500,000
Performance Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total number of shares of common stock that may be subject to grant awards (in shares)	83,333
Performance Restricted Stock Units (RSUs) | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share multiplier (as a percent)	100.00%