Capital Stock and Derivative Instruments - Summary of Company's Restricted Share Award Activity (Detail) - Restricted stock award [Member] - USD ($) $ / shares in Units, $ in Thousands				12 Months Ended
Jun. 01, 2016	May 15, 2015	Apr. 28, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Restricted Stock Awards Outstanding, Beginning balance				6,168,035	2,343,245	1,842,351
Number of Restricted Stock Awards Outstanding, Restricted stock awards granted	212,765	3,555,556	269,234	212,765	3,824,790	500,894
Number of Restricted Stock Awards Outstanding, Restricted stock awards released or forfeited				0	0	0
Number of Restricted Stock Awards Outstanding, Ending balance				6,380,800	6,168,035	2,343,245
Weighted Average Grant Date Fair Value, Beginning balance				$ 2.1230	$ 1.1023	$ 0.6787
Weighted Average Grant Date Fair Value, Restricted stock awards granted				2.3500	2.7486	2.6602
Weighted Average Grant Date Fair Value, Restricted stock awards released or forfeited				0	0	0
Weighted Average Grant Date Fair Value, Ending balance				$ 2.1306	$ 2.1230	$ 1.1023
Aggregate Fair Value, Beginning balance				$ 13,095	$ 2,582	$ 1,250
Aggregate Fair Value, Restricted stock awards granted				500	10,513	1,332
Aggregate Fair Value, Restricted stock awards released or forfeited				0	0	0
Aggregate Fair Value, Ending balance				$ 13,595	$ 13,095	$ 2,582

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(3)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(3)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(i)-(ii)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(i)-(ii)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Share based compensation arrangement by share based payment award equity instruments other than options aggregate fair value outstanding.

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Share based compensation arrangement by share based payment award equity instruments other than options forfeited and expirations In period aggregate fair value.

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Share based compensation arrangement by share based payment award equity instruments other than options grants in period aggregate fair value.

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