Long-term Incentive Compensation (Summary of Equity-Classified Stock Option Activity) (Details) - Stock options shares in Thousands	9 Months Ended
	Sep. 30, 2020 $ / shares shares
Number of Options
Beginning balance (in shares) | shares	4,635
Granted (in shares) | shares	0
Exercised (in shares) | shares	0
Forfeited or expired (in shares) | shares	(357)
Ending balance (in shares) | shares	4,278
Exercisable (in shares) | shares	4,278
Weighted Average Exercise Price
Beginning balance (in dollars per share) | $ / shares	$ 15.26
Granted (in dollars per share) | $ / shares	0
Exercised (in dollars per share) | $ / shares	0
Forfeited or expired (in dollars per share) | $ / shares	7.06
Ending balance (in dollars per share) | $ / shares	15.95
Exercisable (in dollars per share) | $ / shares	$ 15.95