Stock-Based Compensation - Long-Term Performance-Based Plans (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2017	Jun. 30, 2013
LTIP 2008
Share-based compensation additional disclosures
Portion meeting vesting condition (as a percent)					100.00%
LTIP 2013
Share-based compensation additional disclosures
Portion meeting vesting condition (as a percent)				20.00%
Percentage of performance goals probable of achievement	30.00%	10.00%	20.00%
LTIP 2017
Share-based compensation additional disclosures
Portion meeting vesting condition (as a percent)				75.00%