Schedule of quarterly results of operations (unaudited) |
| | | | | | | | | | | | | | | | | | | | | | | | Year ended December 31, 2017 | (in thousands, except per share data) | | First quarter | | Second quarter | | Third quarter | | Fourth quarter | | Year | Operating revenue | | $ | 399,316 |
| | $ | 448,564 |
| | $ | 442,492 |
| | $ | 401,402 |
| | $ | 1,691,774 |
| Operating expenses | | 332,782 |
| | 365,520 |
| | 361,656 |
| | 343,444 |
| | 1,403,402 |
| Investment income | | 6,586 |
| | 6,448 |
| | 8,406 |
| | 7,121 |
| | 28,561 |
| Interest expense, net | | 166 |
| | 257 |
| | 377 |
| | 438 |
| | 1,238 |
| Income before income taxes | | 72,954 |
| | 89,235 |
| | 88,865 |
| | 64,641 |
| | 315,695 |
| Net income | | $ | 47,876 |
| | $ | 58,527 |
| | $ | 58,543 |
| | $ | 32,053 |
| | $ | 196,999 |
| | | | | | | | | | | | Earnings per share (1) | | | | | | | | | | | Net income per share | | | | | | | | | | | Class A common stock – basic | | $ | 1.03 |
| | $ | 1.26 |
| | $ | 1.26 |
| | $ | 0.69 |
| | $ | 4.23 |
| Class A common stock – diluted (2) | | $ | 0.91 |
| | $ | 1.12 |
| | $ | 1.12 |
| | $ | 0.61 |
| | $ | 3.76 |
| Class B common stock – basic | | $ | 154 |
| | $ | 189 |
| | $ | 189 |
| | $ | 103 |
| | $ | 635 |
| Class B common stock – diluted | | $ | 154 |
| | $ | 188 |
| | $ | 189 |
| | $ | 103 |
| | $ | 634 |
|
| | (1) | The cumulative sum of quarterly basic and diluted net income per share amounts may not equal total basic and diluted net income per share for the year due to differences in weighted average shares and equivalent shares outstanding for each of the periods presented. |
| | (2) | Class A diluted earnings per share was reduced by $0.19 for the fourth quarter and total year as a result of increased income tax expense from enactment of the TCJA of $10.1 million. See Note 3, "Earnings Per Share" and Note 10, "Income Taxes". |
| | | | | | | | | | | | | | | | | | | | | | | | Year ended December 31, 2016 | (in thousands, except per share data) | | First quarter | | Second quarter | | Third quarter | | Fourth quarter | | Year | Operating revenue | | $ | 374,728 |
| | $ | 423,884 |
| | $ | 418,406 |
| | $ | 379,613 |
| | $ | 1,596,631 |
| Operating expenses | | 307,063 |
| | 338,125 |
| | 336,151 |
| | 322,928 |
| | 1,304,267 |
| Investment income | | 2,559 |
| | 7,404 |
| | 4,326 |
| | 13,539 |
| | 27,828 |
| Interest expense, net | | — |
| | — |
| | — |
| | 101 |
| | 101 |
| Income before income taxes | | 70,224 |
| | 93,163 |
| | 86,581 |
| | 70,123 |
| | 320,091 |
| Net income | | $ | 45,895 |
| | $ | 61,309 |
| | $ | 57,376 |
| | $ | 45,786 |
| | $ | 210,366 |
| | | | | | | | | | | | Earnings per share (1) | | | | | | | | | | | Net income per share | | | | | | | | | | | Class A common stock – basic | | $ | 0.99 |
| | $ | 1.32 |
| | $ | 1.23 |
| | $ | 0.98 |
| | $ | 4.52 |
| Class A common stock – diluted | | $ | 0.87 |
| | $ | 1.17 |
| | $ | 1.09 |
| | $ | 0.87 |
| | $ | 4.01 |
| Class B common stock – basic | | $ | 148 |
| | $ | 197 |
| | $ | 185 |
| | $ | 147 |
| | $ | 678 |
| Class B common stock – diluted | | $ | 148 |
| | $ | 197 |
| | $ | 185 |
| | $ | 147 |
| | $ | 677 |
|
| | (1) | The cumulative sum of quarterly basic and diluted net income per share amounts may not equal total basic and diluted net income per share for the year due to differences in weighted average shares and equivalent shares outstanding for each of the periods presented. |
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