Stockholders' Equity and Equity Compensation (Tables)

9 Months Ended

Sep. 30, 2018

Equity [Abstract]

Summary of all stock award activity

A summary of the stock award activity is as follows:

	Nine Months Ended   September 30, 2018
	Stock Awards		Weighted Average Award Date Fair Value
Outstanding at December 31, 2017	1,428,878		$	21.53
Restricted stock units awarded	279,459		24.14
Performance stock units awarded	219,943		23.25
Restricted stock units distributed	(301,041	)	17.37
Performance stock units distributed	(296,909	)	21.55
Restricted stock units forfeited	(78,171	)	21.52
Performance stock units forfeited	(61,952	)	26.42
Outstanding at September 30, 2018	1,190,207		$	23.26

Summary of all deferred stock unit activity

A summary of deferred stock unit activity is as follows:

	Nine Months Ended   September 30, 2018
	Deferred Stock Units		Weighted Average Award Date Fair Value
Outstanding at December 31, 2017	269,977		$	20.14
Awarded	43,729		23.67
Distributed	(26,396	)	19.32
Outstanding at September 30, 2018	287,310		$	20.76

Financial data for stock option exercises

Financial data for stock option exercises are summarized as follows (in thousands):

	Nine Months Ended September 30,
	2018		2017
Aggregate intrinsic value of outstanding stock options	$	384	$	478
Aggregate intrinsic value of exercisable stock options	384		478