Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2018

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Restricted shares, performance-based restricted share units and performance share unit activity

The following table presents activity for non-vested RSUs and performance share units under the Plan in 2018.

	Number of Awards		Weighted-Average Grant Date Fair Value
Balance as of January 1, 2018	2,070,737		$	38.92
Awards granted	840,961		51.64
Awards vested	(463,725	)	38.62
Awards forfeited, canceled or expired	(307,719	)	40.59
Performance-based adjustment	63,894		52.00
Balance as of December 31, 2018	2,204,148		43.98