XML 133 R33.htm IDEA: XBRL DOCUMENT
v3.20.1

Note 1 - Nature of Business and Significant Accounting Policies (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2019
Notes Tables |
Fair value of stock option grants |
|  | 2019 |  | 2018 |  | 2017 |
Dividend yield |  |  | 0.67% |  |  | 0.45% to 0.48% |  |  | 0.36% to 0.47% |
Expected volatility |  |  | 28.28% |  |  | 29.51% to 29.59% |  |  | 29.64% to 29.95% |
Risk-free interest rate |  |  | 2.90% |  |  | 2.60% to 2.94% |  |  | 2.50% to 2.81% |
Expected life of option grants |  |  | 6.25 years |  |  | 6 years |  |  | 6 years |
Weighted-average grant date fair value |  | $ | 11.29 |  | $ | 14.68 |  | $ | 14.75 |
|  | 2019 |  | 2018 |  | 2017 |
Dividend yield |  |  | 0.69% to 0.75% |  |  | 0.37% to 0.51% |  |  | 0.37% to 0.42% |
Expected volatility |  |  | 20.15% to 21.06% |  |  | 20.90% to 21.40% |  |  | 19.80% to 19.86% |
Risk-free interest rate |  |  | 2.02 % to 2.46% |  |  | 1.59% to 2.22% |  |  | 0.67% to 1.18% |
Expected life of purchase grants |  |  | 3 to 6 months |  |  | 3 to 6 months |  |  | 3 to 6 months |
Weighted-average grant date fair value |  | $ | 4.81 |  | $ | 6.63 |  | $ | 6.42 |

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=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

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