XML 55 R36.htm IDEA: XBRL DOCUMENT
v3.3.1.900

Note 1 - Nature of Business and Significant Accounting Policies (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2015
Accounting Policies [Abstract] |
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] |
|  | 2015 |  |  | 2014 |  |  | 2013 |
Dividend yield |  | .37% | to | .46% |  |  |  | .47% |  |  |  | .44% | to | .53% |
Expected volatility |  | 28.92% | to | 29.32% |  |  | 29.07% | to | 29.18% |  |  | 29.50% | to | 30.56% |
Risk-free interest rate |  | 1.89% | to | 2.37% |  |  | 2.69% | to | 2.82% |  |  | 1.71% | to | 2.90% |
Expected life of option grants (years) |  |  | 6 |  |  |  |  | 6 |  |  |  |  | 6 |  |
Weighted-average grant date fair value |  |  | $5.11 |  |  |  |  | $5.68 |  |  |  |  | $5.14 |  |
|  | 2015 |  |  | 2014 |  |  | 2013 |
Dividend yield |  | .37% | to | .45% |  |  | .46% | to | .47% |  |  | .53% | to | .61% |
Expected volatility |  | 8.81% | to | 13.10% |  |  | 16.96% | to | 19.35% |  |  | 23.05% | to | 24.25% |
Risk-free interest rate |  | .09% | to | .16% |  |  | .04% | to | .12% |  |  | .10% | to | .18% |
Expected life of purchase grants (months) |  | 3 | to | 6 |  |  | 3 | to | 6 |  |  | 3 | to | 6 |
Weighted-average grant date fair value |  |  | $2.39 |  |  |  |  | $2.37 |  |  |  |  | $2.10 |  |

X
- References No definition available. + Details
Name: | us-gaap_AccountingPoliciesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
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://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration