Accumulated Other Comprehensive Income Amounts Reclassified (Details) - USD ($)
$ in Thousands |
3 Months Ended |
9 Months Ended |
12 Months Ended |
Sep. 30, 2016 |
Sep. 30, 2015 |
Sep. 30, 2016 |
Sep. 30, 2015 |
Sep. 30, 2016 |
Sep. 30, 2015 |
| Accumulated Other Comprehensive Income (Loss) [Line Items] |
|
|
|
|
|
|
|
| Income (Loss) before income tax |
|
$ 117,770
|
$ 81,340
|
$ 142,535
|
$ 116,359
|
$ 142,989
|
$ 122,790
|
| Income tax expense |
|
(43,134)
|
(24,600)
|
(51,423)
|
(35,089)
|
(51,229)
|
(37,279)
|
| Net (Income) Loss |
|
74,636
|
56,740
|
91,112
|
81,270
|
91,760
|
85,511
|
| Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent |
|
|
|
|
|
|
|
| Accumulated Other Comprehensive Income (Loss) [Line Items] |
|
|
|
|
|
|
|
| Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax |
[1] |
1,663
|
1,606
|
4,993
|
4,931
|
6,636
|
6,996
|
| Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent |
|
|
|
|
|
|
|
| Accumulated Other Comprehensive Income (Loss) [Line Items] |
|
|
|
|
|
|
|
| Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax |
[1] |
(1,087)
|
(1,966)
|
(3,532)
|
(6,466)
|
(5,688)
|
(8,081)
|
| Accumulated Defined Benefit Plans Adjustment |
|
|
|
|
|
|
|
| Accumulated Other Comprehensive Income (Loss) [Line Items] |
|
|
|
|
|
|
|
| Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax |
[1] |
576
|
(360)
|
1,461
|
(1,535)
|
948
|
(1,085)
|
| Reclassification from AOCI, Current Period, Tax |
|
228
|
134
|
6
|
756
|
60
|
597
|
| Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax |
[1] |
804
|
(226)
|
1,467
|
(779)
|
1,008
|
(488)
|
| Accumulated Net Unrealized Investment Gain (Loss) |
|
|
|
|
|
|
|
| Accumulated Other Comprehensive Income (Loss) [Line Items] |
|
|
|
|
|
|
|
| Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax |
|
1,687
|
3,472
|
4,493
|
6,334
|
7,096
|
9,219
|
| Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges |
|
|
|
|
|
|
|
| Accumulated Other Comprehensive Income (Loss) [Line Items] |
|
|
|
|
|
|
|
| Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax |
|
39
|
(72)
|
(78)
|
(187)
|
(155)
|
(259)
|
| Reclassification out of Accumulated Other Comprehensive Income |
|
|
|
|
|
|
|
| Accumulated Other Comprehensive Income (Loss) [Line Items] |
|
|
|
|
|
|
|
| Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax |
|
2,530
|
3,174
|
5,882
|
5,368
|
7,949
|
8,472
|
| Reclassification out of Accumulated Other Comprehensive Income | Accumulated Net Unrealized Investment Gain (Loss) |
|
|
|
|
|
|
|
| Accumulated Other Comprehensive Income (Loss) [Line Items] |
|
|
|
|
|
|
|
| Net realized gain on sale of securities |
|
2,072
|
4,324
|
5,570
|
7,887
|
8,797
|
11,446
|
| Income (Loss) before income tax |
|
2,072
|
4,324
|
5,570
|
7,887
|
8,797
|
11,446
|
| Income tax expense |
|
(385)
|
(852)
|
(1,077)
|
(1,553)
|
(1,701)
|
(2,227)
|
| Net (Income) Loss |
|
1,687
|
3,472
|
4,493
|
6,334
|
7,096
|
9,219
|
| Reclassification out of Accumulated Other Comprehensive Income | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges |
|
|
|
|
|
|
|
| Accumulated Other Comprehensive Income (Loss) [Line Items] |
|
|
|
|
|
|
|
| Income (Loss) before income tax |
|
(126)
|
(118)
|
(371)
|
(348)
|
(490)
|
(460)
|
| Income tax expense |
|
165
|
46
|
293
|
161
|
335
|
201
|
| Net (Income) Loss |
|
39
|
(72)
|
(78)
|
(187)
|
(155)
|
(259)
|
| Interest Rate Contract | Reclassification out of Accumulated Other Comprehensive Income | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges |
|
|
|
|
|
|
|
| Accumulated Other Comprehensive Income (Loss) [Line Items] |
|
|
|
|
|
|
|
| Interest on long-term debt and revolving credit facility |
|
$ (126)
|
$ (118)
|
$ (371)
|
$ (348)
|
$ (490)
|
$ (460)
|
|
|