Stock-Based Compensation - Performance Incentive Plan Vesting Levels (Details) - 2008 Performance Incentive Plan - Restricted Stock Units (RSUs)	1 Months Ended
	Jul. 31, 2016 $ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Price Level	$ 50.00
Percentage of Total Award That Vests	100.00%
Performance Level One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Price Level	$ 50.00
Percentage of Total Award That Vests	25.00%
Performance Level Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Price Level	$ 60.00
Percentage of Total Award That Vests	50.00%
Performance Level Three
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Price Level	$ 70.00
Percentage of Total Award That Vests	25.00%