Other Comprehensive Loss - Changes in Components of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Changes in the components of accumulated other comprehensive loss, net of taxes
Balance at beginning of period			$ (219,641)	$ (216,378)
Net current period other comprehensive loss (income)	$ (48)	$ (20)	(31)	(60)
Balance at end of period	(225,716)	(218,364)	(225,716)	(218,364)
Accumulated Other Comprehensive Income (Loss)
Changes in the components of accumulated other comprehensive loss, net of taxes
Balance at beginning of period	5,253	5,348	5,236	5,388
Other comprehensive loss (income), net of taxes	(48)	(20)	(31)	(60)
Net current period other comprehensive loss (income)	(48)	(20)	(31)	(60)
Balance at end of period	5,205	5,328	5,205	5,328
Unfunded Pension Liability
Changes in the components of accumulated other comprehensive loss, net of taxes
Balance at beginning of period	5,065	5,032	5,044	5,032
Other comprehensive loss (income), net of taxes	0	64	21	64
Net current period other comprehensive loss (income)		64	21	64
Balance at end of period	5,065	5,096	5,065	5,096
Noncredit Related Loss
Changes in the components of accumulated other comprehensive loss, net of taxes
Balance at beginning of period	145	253	147	284
Other comprehensive loss (income), net of taxes	(44)	(77)	(46)	(108)
Net current period other comprehensive loss (income)	(44)	(77)	(46)	(108)
Balance at end of period	101	176	101	176
Unrealized Loss on Securities
Changes in the components of accumulated other comprehensive loss, net of taxes
Balance at beginning of period	43	63	45	72
Other comprehensive loss (income), net of taxes	(4)	(7)	(6)	(16)
Net current period other comprehensive loss (income)	(4)	(7)	(6)	(16)
Balance at end of period	$ 39	$ 56	$ 39	$ 56

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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- Definition

Amount after tax, before reclassification adjustments, of other comprehensive income (loss), attributable to parent.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 55
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=51821188&loc=d3e1436-108581

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-Publisher FASB
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-URI http://asc.fasb.org/extlink&oid=36458714&loc=SL7669686-108580

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Amount after tax of other comprehensive income (loss) attributable to parent entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (c)(3)
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-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=51664549&loc=SL4569616-111683

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- Definition

Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB TOPIC 4.E)
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-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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-Publisher SEC
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