Amortization term related to performance shares.

No definition available.

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- Definition

Final Number Of Potential Performance Shares Issuable Maximum.

+ References

No definition available.

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- Definition

Final Number Of Potential Performance Shares Issuable Minimum.

+ References

No definition available.

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- Definition

Grant date fair value of performance share units.

+ References

No definition available.

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- Definition

Number of performance share units granted.

+ References

No definition available.

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- Definition

Performance periods.

+ References

No definition available.

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- Definition

Performance Units Adjustment For Performance Multiplier Multiplier Assumed.

+ References

No definition available.

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- Definition

Performance units adjustment for performance multiplier range maximum.

+ References

No definition available.

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- Definition

Performance units adjustment for performance multiplier range minimum.

+ References

No definition available.

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- Definition

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

+ References

No definition available.

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- Definition

Share based compensation arrangement by share based payment award equity instruments other than options unrecognized compensation cost.

+ References

No definition available.

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- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 14.F)
-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901

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

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 14
-Section F

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- Definition

Unrecognized cost of unvested share-based compensation awards.

+ 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 (i)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ 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 (a)(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

Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

+ 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 (d)(2)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The estimated measure of the maximum percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

+ References

No definition available.

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- Definition

The estimated measure of the minimum percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

+ References

No definition available.

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- Definition

The risk-free interest rate assumption that is used in valuing an option on its own shares.

+ 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 (f)(2)(iv)
-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.

+ References

No definition available.

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Stock-based Compensation - Additional Information 1 (Detail) $ / shares in Units, $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2016 USD ($) Unit $ / shares $ / EquityUnit	Dec. 31, 2015 USD ($) Unit $ / shares $ / EquityUnit shares	Dec. 31, 2014 USD ($) Unit $ / shares $ / EquityUnit	Dec. 31, 2013 USD ($) $ / shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Performance multiplier, minimum	0.00%	0.00%
Performance multiplier, maximum	200.00%	300.00%
Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Compensation expense recognized		$ 6.0	$ 7.3	$ 9.8
Grant date fair value of share units, per share \| $ / shares	$ 5.45	$ 26.70	$ 101.20	$ 82.20
Unrecognized compensation cost related to unvested restricted stock	$ 4.4	$ 5.1
Period in which compensation cost expected to be recognized	2 years 1 month 6 days	1 year 9 months 18 days
Fair value of restricted stock vested		$ 3.7	$ 10.0	$ 7.0
Restricted stock grant date fair value	$ 1.3
Potential Performance Shares (PSU)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Compensation expense recognized		$ 2.1	$ 3.4	$ 3.0
Unrecognized compensation cost related to unvested restricted stock	$ 1.7
Period in which compensation cost expected to be recognized	1 year 8 months 12 days
Performance Periods		The performance periods consist of one year, two years and three years, respectively
Performance share units, risk free interest rate		1.10%	0.60%
Performance share units, Minimum volatility		37.00%	38.00%
Performance share units, Maximum volatility		65.00%	70.00%
Number of units granted \| Unit	60,013	94,250	37,792
Restricted stock grant date fair value		$ 0.7	$ 3.7
Grant date fair value of share units, per unit \| $ / EquityUnit	7.00	7.30	99.05
Performance multiplier assumed \| shares		1
Minimum final number of shares of common stock issuable based on performance multiplier \| shares		0
Maximum final number of shares of common stock issuable based on performance multiplier \| shares		280,035
Performance multiplier, minimum		0.00%
Performance multiplier, maximum		200.00%
Unrecognized expense, performance share units		$ 2.0
Term for Amortization of Performance Share Compensation cost		through December 31, 2017.
Minimum \| Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Amortized vesting period of restricted stock		1 year
Minimum \| Potential Performance Shares (PSU)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Amortized vesting period of restricted stock		1 year
Maximum \| Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Amortized vesting period of restricted stock		4 years
Maximum \| Potential Performance Shares (PSU)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Amortized vesting period of restricted stock		3 years