Stock-Based Incentive Compensation Plans (Details)	3 Months Ended
	Mar. 31, 2018 shares
Stock options [Member]
Share-based compensation arrangement by share-based payment award [Line Items]
Shares granted	453,941
Performance Shares [Member]
Share-based compensation arrangement by share-based payment award [Line Items]
Shares granted	156,245
Restricted Stock Units [Member]
Share-based compensation arrangement by share-based payment award [Line Items]
Shares granted	590,500
Non-employee Stock Appreciation Rights [Member]
Share-based compensation arrangement by share-based payment award [Line Items]
Shares granted	14,692
Non-employee Agent Stock Options [Member]
Share-based compensation arrangement by share-based payment award [Line Items]
Shares granted	32,400
Non-employee Director Deferred Stock Units [Member]
Share-based compensation arrangement by share-based payment award [Line Items]
Shares granted	6,653