XML 49 R31.htm IDEA: XBRL DOCUMENT
v3.21.2

Stock-Based Compensation (Tables) | 6 Months Ended
--- | ---
Jun. 30, 2021
Share-based Payment Arrangement [Abstract] |
Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan | The following table summarizes our stock-based compensation expense (including stock options, restricted stock units ("RSUs") and performance stock units ("PSUs")) for the three and six months ended June 30, 2021 and 2020:
| Three Months Ended June 30, |  | Six Months Ended June 30,
(in millions) | 2021 |  | 2020 |  | 2021 |  | 2020
Stock option compensation expense | $ | 0.6 |  |  | $ | 0.8 |  |  | $ | 2.3 |  |  | $ | 1.6 |
RSU compensation expense | 0.9 |  |  | 2.0 |  |  | 3.4 |  |  | 3.0 |
PSU compensation expense | 2.7 |  |  | (0.3) |  |  | 3.3 |  |  | (1.2) |
Total stock-based compensation expense | $ | 4.2 |  |  | $ | 2.5 |  |  | $ | 9.0 |  |  | $ | 3.4 |
Schedule of Unrecognized Compensation Cost, Nonvested Awards | The following table summarizes our unrecognized compensation expense and the weighted-average period over which the expense will be recognized as of June 30, 2021:
| June 30, 2021
| Unrecognized |  | Weighted Average
| Compensation |  | Years Expense To Be
(in millions, except weighted average years) | Expense |  | Recognized Over
Stock options | $4.6 |  | 2.2
RSUs | $5.1 |  | 1.8
PSUs | $14.0 |  | 1.9

X
- References No definition available. + Details
Name: | us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of cost recognized for award under share-based payment arrangement by plan. Includes, but is not limited to, related tax benefit. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ScheduleOfCompensationCostForShareBasedPaymentArrangementsAllocationOfShareBasedCompensationCostsByPlanTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of cost not yet recognized and weighted-average period over which cost is expected to be recognized for nonvested award under share-based payment arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ScheduleOfUnrecognizedCompensationCostNonvestedAwardsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration