Incentive Plan (Market Performance Based Awards) (Details)	6 Months Ended
	Jun. 30, 2015
2014 Performance Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Market Performance Vesting Percentage	0.00%
RMS Relative Market Performance	0.00%
2015 Performance Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RMS Relative Market Performance	(3.00%)
Threshold Level | 2014 Performance Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Market Performance Vesting Percentage	25.00%
RMS Relative Market Performance	0.00%
Threshold Level | 2015 Performance Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RMS Relative Market Performance	(3.00%)
Target Level | 2014 Performance Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Market Performance Vesting Percentage	50.00%
RMS Relative Market Performance	3.25%
Target Level | 2015 Performance Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RMS Relative Market Performance	1.00%
High Level | 2014 Performance Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Market Performance Vesting Percentage	100.00%
RMS Relative Market Performance	6.50%
High Level | 2015 Performance Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RMS Relative Market Performance	5.00%