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Cash and Investments in Marketable Securities - Additional Information (Detail) - USD ($) |  | 12 Months Ended
--- | --- | ---
Oct. 05, 2015 | Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Cash and Investments in Marketable Securities [Line Items] |  |  |  |
Maximum maturity term for debt securities investment |  | Two years or less |  |
Weighted average maturity term for debt securities investment |  | One year or less |  |
Available-for-sale securities, sold |  | $ 42,500,000 | $ 21,700,000 | $ 2,900,000
Restricted cash |  | 0 | 25,000,000 |
Level 1 to level 2 transfers |  | 0 | 0 | 0
Level 2 to level 1 transfers |  | 0 | 0 | $ 0
Letter of credit |  | $ 2,400,000 | $ 2,400,000 |
7.75% Senior Secured Notes Due October 2020 [Member] |  |  |  |
Cash and Investments in Marketable Securities [Line Items] |  |  |  |
Senior secured notes, interest rate |  | 7.75% |  |
Senior Notes [Member] | 12% Senior Secured Notes Due July 2017 [Member] |  |  |  |
Cash and Investments in Marketable Securities [Line Items] |  |  |  |
Restricted cash | $ 25,000,000 |  |  |
Senior secured notes, interest rate | 12.00% |  |  |
Senior secured notes, maturity date | Jul. 15, 2017 |  |  |
Senior Notes [Member] | 7.75% Senior Secured Notes Due October 2020 [Member] |  |  |  |
Cash and Investments in Marketable Securities [Line Items] |  |  |  |
Senior secured notes, interest rate | 7.75% | 7.75% |  |
Senior secured notes, maturity date |  | Oct. 05, 2020 |  |
Minimum cash and investments in marketable securities to be maintained |  | $ 60,000,000 |  |

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- Definition Debt investment maturity date description. + References No definition available. + Details
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- Definition Minimum cash and investments in marketable securities to be maintained. + References No definition available. + Details
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- Definition The total amount of proceeds received for the sale of securities, categorized neither as held-to-maturity nor trading securities, during the reporting period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 9 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27357-111563 + Details
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- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(2)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition Amount of transfers of assets measured on a recurring basis out of Level 2 of the fair value hierarchy into Level 1. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bb) -URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258 + Details
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- Definition The carrying amounts of cash and cash equivalent items which are restricted as to withdrawal or usage. Restrictions may include legally restricted deposits held as compensating balances against short-term borrowing arrangements, contracts entered into with others, or entity statements of intention with regard to particular deposits; however, time deposits and short-term certificates of deposit are not generally included in legally restricted deposits. Excludes compensating balance arrangements that are not agreements which legally restrict the use of cash amounts shown on the balance sheet. For a classified balance sheet represents the current portion only (the noncurrent portion has a separate concept); there is a separate and distinct element for unclassified presentations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.1) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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