Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2020

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Share-Based Compensation Arrangements, Vested Stock Grants

Stock-based compensation expense related to vested stock grants are included in General and administrative expenses within the Consolidated Statements of (Loss) Income. The Company’s authorized vested stock grants to certain directors and related expense for the years ended December 31, 2020, 2019 and 2018, was as follows:

	Year Ended December 31,
(millions, except stock grants)	2020		2019		2018
Vested stock grants		25,066		14,076		12,736
Stock-based compensation expense	$	0.5	$	0.5	$	0.5

Summary of Nonvested Restricted Stock Units and Changes During the Period

Nonvested restricted stock units as of December 31, 2020, and changes during the year ended December 31, 2020 were as follows:

	Shares			Weighted Average Grant-Date Fair Value
Nonvested as of December 31, 2019		153,442		$	27.46
Granted		—			—
Vested		(102,166	)		24.56
Forfeited		—			—
Nonvested as of December 31, 2020		51,276		$	33.24

Summary of Compensation Expense Related to Restricted Stock Units

The Company's stock-based compensation expense related to the restricted stock units for the years ended December 31, 2020, 2019 and 2018, which is included in General and administrative expenses within the Consolidated Statements of (Loss) Income, was as follows:

	Year Ended December 31,
(millions)	2020		2019		2018
Stock-based compensation expense	$	1.1	$	1.1	$	0.9

The Company's stock-based compensation expense (net reduction of expense) related to PSU’s during the years ended December 31, 2020, 2019 and 2018, which is included in General and administrative expenses within the Consolidated Statements of (Loss) Income, was as follows:

	Year Ended December 31,
(millions)	2020			2019		2018
Stock-based compensation expense	$	(1.0	)	$	3.3	$	1.4

Summary of Unrecognized Compensation Expense Related to Share Based Payment

Unrecognized stock-based compensation expense related to restricted stock units and the respective weighted average periods in which the expense will be recognized as of December 31, 2020 was as follows:

	Year Ended December 31,
(millions)	2020
Unrecognized stock-based compensation	$	0.6
Weighted average (years)	1.2 years

Summary of Nonvested PSU's and Changes During the Period

Nonvested PSU’s as of December 31, 2020, and changes during the year ended December 31, 2020 was as follows:

	Shares			Weighted Average Grant-Date Fair Value
Nonvested as of December 31, 2019		212,096		$	35.01
Granted		96,056			37.89
Vested		(81,115	)		30.01
Forfeited		(23,173	)		36.27
Expired		(3,646	)		37.59
Nonvested as of December 31, 2020		200,218		$	35.27