Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
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-Article 12
-Section 13
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Debt instrument interest additional interest above base rate.

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Floating Euro Dollar Based Rate

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
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Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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Contractual interest rate for funds borrowed, under the debt agreement.

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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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Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount, before accumulated amortization, of debt issuance costs related to line of credit arrangements. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-SubTopic 30
-Section S45
-Paragraph 1
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Amount, after accumulated amortization, of debt issuance costs related to line of credit arrangements. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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- Definition

Fixed interest rate related to the interest rate derivative.

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The number of derivative instruments of a particular group held by the entity.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Period the derivative contract is outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Fair value of all derivatives designated as interest rate fair value hedging instruments.

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The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

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Amount of decrease in line of credit facility from forgiveness by the holder of the line of credit.

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The effective interest rate at the end of the reporting period.

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Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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Debt (Detail) - Borrowings	6 Months Ended	12 Months Ended
Debt (Detail) - Borrowings	Jun. 30, 2016 USD ($) outstanding_contract contract	Dec. 31, 2012 USD ($)	Dec. 31, 2015 USD ($) outstanding_contract
Debt Instrument [Line Items]
Number of derivative contracts \| outstanding_contract	25		105
Long-term debt, gross	$ 835,000,000		$ 825,000,000
Debt issuance costs, line of credit arrangements, net	$ (8,985,000)		0
Debt instrument interest additional interest above base rate	1.38%
Notional amount of interest rate derivatives	$ 731,900,000		893,610,000
Debt instrument, effective percentage	2.75%
Interest rate swap
Debt Instrument [Line Items]
Number of derivative contracts \| contract	3
Notional amount of interest rate derivatives	$ 700,000,000
Derivative, term of contract	30 days
Interest rate, fair value hedge derivative at fair value, net (negative fair value)	$ 20,300,000
Interest rate swap \| Minimum
Debt Instrument [Line Items]
Derivative, fixed interest rate	1.53%
Interest rate swap \| Maximum
Debt Instrument [Line Items]
Derivative, fixed interest rate	1.60%
Previous Debt Excluding 2016 Credit Agreement
Debt Instrument [Line Items]
Debt issuance costs, gross	$ 3,900,000
Bank Term Loan
Debt Instrument [Line Items]
Long-term debt, gross	$ 600,000,000		380,000,000
Contractual annualized interest rate	1.84%
Floating eurodollar based rate	0.46%
Bank Term Loan \| Interest rate swap
Debt Instrument [Line Items]
Notional amount of interest rate derivatives	$ 700,000,000
Connecticut Economic Development Program
Debt Instrument [Line Items]
Long-term debt, gross	5,000,000		5,000,000
Debt instrument, fixed interest rate		3.00%
Debt instrument term		10 years
Debt instrument, period principal payments are deferred		5 years
Line of credit facility, decrease, forgiveness (up to)		$ 2,500,000.0
Debt instrument, forgiveness period under the terms of the loan		5 years
Revolving credit facility
Debt Instrument [Line Items]
Long-term debt, gross	$ 230,000,000		$ 440,000,000
Contractual annualized interest rate	1.84%
Line of credit facility, remaining borrowing capacity	$ 966,000,000
Letter of Credit
Debt Instrument [Line Items]
Letters of credit outstanding, amount	4,000,000
Interest expense, net \| 2016 Credit Facility Agreement
Debt Instrument [Line Items]
Debt issuance costs, gross	$ 5,000,000