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Income Taxes - Additional Information (Detail) (USD $)
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12 Months Ended |
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Dec. 31, 2014
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Dec. 31, 2013
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Dec. 31, 2012
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| Valuation Allowance [Line Items] |
|
|
|
| Valuation allowance |
$ 163,500,000 |
$ 166,100,000 |
$ 151,800,000 |
| Change in valuation allowance |
(2,600,000) |
14,300,000 |
9,400,000 |
| Change in Deferred Tax Asset Valuation Allowance resulted from net operating loss carryforwards. |
(6,400,000) |
|
|
| Change in Deferred Tax Asset Valuation Allowance resulted from capital loss carryforwards |
3,000,000 |
|
|
| Change in Deferred Tax Asset Valuation Allowance resulted from temporary differences not attributable to indefinite-lived intangible assets |
800,000 |
8,000,000 |
|
| Change in Deferred Tax Asset Valuation Allowance resulted from net operating and capital loss carryforwards. |
|
9,600,000 |
14,900,000 |
| Change in Deferred Tax Asset Valuation Allowance resulted from change in reporting methodology for Other Comprehensive Income. |
|
(3,300,000) |
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| Change in Deferred Tax Liabilities associated with temporary differences not attributable to indefinite-lived intangible assets |
|
|
5,500,000 |
| Tax liability for uncertain tax positions |
0 |
0 |
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| Federal [Member] |
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|
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| Valuation Allowance [Line Items] |
|
|
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| Federal NOL carryforwards |
$ 248,300,000 |
$ 263,700,000 |
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| Federal NOL carryforwards expiration |
2027 |
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