XML 47 R35.htm IDEA: XBRL DOCUMENT
v3.21.2

SHARE-BASED COMPENSATION AND BENEFIT PLANS (Tables) | 6 Months Ended
--- | ---
Jun. 30, 2021
Employee stock option [Member] |
Share-Based Compensation and Benefit Plans |
Summary of stock options | ​
​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Shares | ​ | Weighted- Average
​ | ​ | (in thousands) | ​ | Exercise Price
Outstanding at December 31, 2020 |  | 1,500 | ​ | $ | 248.52
Granted |  | 110 | ​ |  | 467.05
Exercised |  | (206) | ​ |  | 163.63
Forfeited or expired |  | (9) | ​ |  | 337.54
Outstanding at June 30, 2021 |  | 1,395 | ​ | $ | 277.79
Exercisable at June 30, 2021 |  | 959 | ​ | $ | 229.94
Black-Scholes option pricing model | ​
​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | June 30,
​ |  | 2021 | ​ | 2020
Risk free interest rate |  | 0.83 | % | ​ | 0.96 | %
Expected life |  | 6.2 | Years | ​ | 6.2 | Years
Expected volatility |  | 30.0 | % | ​ | 25.8 | %
Expected dividend yield |  | — | % | ​ | — | %
Summary of activity of share-based compensation and benefit plans | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | For the Three Months Ended | ​ | For the Six Months Ended
​ | ​ | June 30, | ​ | June 30,
​ |  | 2021 |  | 2020 |  | 2021 | ​ | 2020
Compensation expense for stock options awarded | ​ | $ | 5,105 | ​ | $ | 4,557 | ​ | $ | 10,367 | ​ | $ | 9,435
Income tax benefit from compensation expense related to stock options | ​ |  | 1,314 | ​ |  | 1,148 | ​ |  | 2,668 | ​ |  | 2,377
Restricted stock [Member] |
Share-Based Compensation and Benefit Plans |
Summary of activity of share-based compensation and benefit plans | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | For the Three Months Ended | ​ | For the Six Months Ended
​ | ​ | June 30, | ​ | June 30,
​ |  | 2021 |  | 2020 |  | 2021 |  | 2020
Compensation expense for shares issued under the ESPP | ​ | $ | 782 | ​ | $ | 697 | ​ | $ | 1,432 | ​ | $ | 1,343
Income tax benefit from compensation expense related to shares issued under the ESPP | ​ | ​ | 201 | ​ | ​ | 176 | ​ | ​ | 368 | ​ | ​ | 338
Compensation expense for restricted shares awarded | ​ | ​ | 396 | ​ | ​ | 351 | ​ | ​ | 776 | ​ | ​ | 702
Income tax benefit from compensation expense related to restricted awards | ​ | $ | 102 | ​ | $ | 88 | ​ | $ | 200 | ​ | $ | 177

X
- Definition Tabular disclosure of 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 1 -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5047-113901 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_DisclosureOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure for stock option plans. Includes, but is not limited to, outstanding awards at beginning and end of year, grants, exercises, forfeitures, and weighted-average grant date fair value. + 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 (d) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the significant assumptions used during the year to estimate the fair value of stock options, including, but not limited to: (a) expected term of share options and similar instruments, (b) expected volatility of the entity's shares, (c) expected dividends, (d) risk-free rate(s), and (e) discount for post-vesting restrictions. + 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 (f)(2) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_EmployeeStockOptionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_RestrictedStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |