Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2016

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

Share-based compensation arrangements, vested stock grants

The following is a summary of Company authorized vested stock grants to certain directors for the year ended December 31, 2016, 2015 and 2014. Stock-based compensation expense related to vested stock grants are included in General and administrative expenses within the Condensed Consolidated Statements of Income.

	Year Ended December 31,
(millions, except stock grants)	2016		2015		2014
Vested stock grants	32,180		32,357		19,336
Stock-based compensation expense	$	0.7	$	0.7	$	0.5

Summary of the transactions pursuant to the stock option plans

A summary of the status of the stock option plans as of December 31, 2016, and changes during the years ended December 31, 2016, 2015 and 2014, are presented below:

	Number of Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value
Outstanding at December 31, 2013	7,101		$	5.75
Granted	—		n/a
Exercised	—		n/a
Expired	—		n/a
Outstanding at December 31, 2014	7,101		$	5.75
Granted	—		n/a
Exercised	(7,101	)	5.75
Expired	—		n/a
Outstanding at December 31, 2015	—		$	5.75
Granted	—		n/a
Exercised	—		n/a
Expired	—		n/a
Vested and Exercisable at December 31, 2016	—		$	—	—	$	—

Summary of the status of the restricted stock units and changes during the period

A summary of the status of the restricted stock units as of December 31, 2016, and changes during the year ended December 31, 2016, 2015 and 2014, are presented below:

	Shares		Weighted Average Grant-Date Fair Value
Nonvested at December 31, 2013	704,751		$	20.00
Issued	31,099		22.20
Vested	(145,421	)	22.41
Forfeited	(34,729	)	23.88
Nonvested at December 31, 2014	555,700		$	19.57
Issued	12,589		23.65
Vested	(150,073	)	20.77
Forfeited	(16,500	)	19.45
Nonvested at December 31, 2015	401,716		$	19.25
Issued	4,020		24.87
Vested	(54,215	)	18.33
Forfeited	(17,324	)	19.68
Nonvested at December 31, 2016	334,197		$	19.45

Summary of compensation expense related to restricted stock units

The table below shows the Company's stock-based compensation expense related to the Performance-Based Incentive Program for the years ended December 31, 2016, 2015 and 2014, and is included in General and administrative expenses within the Condensed Consolidated Statements of Income.

	Year Ended December 31,
(millions)	2016		2015		2014
Stock-based compensation	$	1.8	$	1.3	$	0.3

The table below shows the Company's stock-based compensation expense related to the restricted stock units for the years ended December 31, 2016, 2015 and 2014, and is included in General and administrative expenses within the Condensed Consolidated Statements of Income.

	Year Ended December 31,
(millions)	2016		2015		2014
Stock-based compensation expense	$	0.9	$	1.6	$	2.4

Summary of unrecognized compensation expense related to share based payment

	Year Ended December 31,
(millions)	2016		2015		2014
Stock-based compensation expense	$	0.9	$	1.6	$	2.4

Unrecognized stock-based compensation expense, net of estimated forfeitures, related to the restricted stock units for the years ended December 31, 2016, 2015 and 2014, is shown in the table below, along with the weighted average periods in which the expense will be recognized.

	Year Ended December 31,
(millions)	2016		2015		2014
Unrecognized stock-based compensation	$	1.7	$	2.7	$	4.4
Weighted Average Years	2.8 years		3.8 years		4.0 years

Summary of the status of the performance stock units and changes during the period

A summary of the status of the performance share units as of December 31, 2016, and changes during the year ended December 31, 2016 and 2015 are presented below:

	Shares		Weighted Average Grant-Date Fair Value
Nonvested at December 31, 2014	79,430		$	18.96
Issued	125,392		21.64
Vested	(6,915	)	19.91
Forfeited	(24,056	)	20.30
Nonvested at December 31, 2015	173,851		20.63
Issued	99,466		23.72
Vested	(84,417	)	19.15
Forfeited	(29,423	)	22.52
Nonvested at December 31, 2016	159,477		$	22.99