XML 47 R33.htm IDEA: XBRL DOCUMENT
v3.3.1.900

Unaudited Quarterly Financial Data (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract] |
Schedule of Quarterly Financial Information | Summarized quarterly financial data is as follows:
| 2015 Quarter Ended
| March |  | June |  | September |  | December
Operating revenue | $ | 62,112 |  |  | 72,402 |  |  | 82,955 |  |  | 87,613 |
Operating income | 12,805 |  |  | 17,210 |  |  | 18,260 |  |  | 31,685 |
Net income | 4,695 |  |  | 7,461 |  |  | 9,534 |  |  | 16,192 |
Comprehensive income | 4,680 |  |  | 7,206 |  |  | 9,422 |  |  | 16,368 |
Earnings per share: |  |  |  |  |  |  |
—Basic | 0.23 |  |  | 0.37 |  |  | 0.47 |  |  | 0.79 |
—Diluted | 0.23 |  |  | 0.36 |  |  | 0.46 |  |  | 0.79 |
Market price range of stock: |  |  |  |  |  |  |
—High | 35.60 |  |  | 31.68 |  |  | 31.36 |  |  | 33.68 |
—Low | 30.09 |  |  | 28.68 |  |  | 27.73 |  |  | 27.64 |
Dividend per share | 0.20 |  |  | 0.19 |  |  | 0.20 |  |  | 0.19 |
| 2014 Quarter Ended
| March |  | June |  | September |  | December
Operating revenue | $ | 54,596 |  |  | 70,356 |  |  | 125,430 |  |  | 69,286 |
Operating income | 6,054 |  |  | 12,121 |  |  | 59,114 |  |  | 15,589 |
Net income | 906 |  |  | 6,846 |  |  | 38,366 |  |  | 5,688 |
Comprehensive income | 1,104 |  |  | 5,716 |  |  | 38,095 |  |  | 6,021 |
Earnings per share: |  |  |  |  |  |  |
—Basic | 0.04 |  |  | 0.34 |  |  | 1.90 |  |  | 0.28 |
—Diluted | 0.04 |  |  | 0.34 |  |  | 1.88 |  |  | 0.28 |
Market price range of stock: |  |  |  |  |  |  |
—High | 30.40 |  |  | 29.51 |  |  | 28.25 |  |  | 32.87 |
—Low | 27.84 |  |  | 25.87 |  |  | 25.64 |  |  | 26.77 |
Dividend per share | 0.19 |  |  | 0.19 |  |  | 0.19 |  |  | 0.19 |

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

X
- Definition Tabular disclosure of the quarterly financial data in the annual financial statements. The disclosure includes financial information for each fiscal quarter for the current and previous year, including revenues, gross profit, income (loss) before extraordinary items and cumulative effect of a change in accounting principle and earnings per share data. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 270 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (a)-(j) -URI http://asc.fasb.org/extlink&oid=35737889&loc=d3e1280-108306 + Details
Name: | us-gaap_ScheduleOfQuarterlyFinancialInformationTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration