The amount of payments made for which participants are entitled under a pension plan, including pension benefits, death benefits, and benefits due on termination of employment. Also includes payments made under a postretirement benefit plan, including prescription drug benefits, health care benefits, life insurance benefits, and legal, educational and advisory services. This item represents a periodic decrease to the plan obligations and a decrease to plan assets.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 60
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=6414203&loc=d3e39716-114964

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Benefits
-URI http://asc.fasb.org/extlink&oid=49170737

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)(6)
-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Postretirement Benefits
-URI http://asc.fasb.org/extlink&oid=6521376

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)(5)
-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920

Name:	us-gaap_DefinedBenefitPlanBenefitsPaid
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Benefits Expected to be Paid from Plans Assets (Parenthetical) (Detail) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2016
Includes Plan No 1 and No 2 One Time Voluntary Lump Sum Offer \| Lump Sums Plan No. 1
Schedule of Pension and Other Postretirement Benefits Expected Benefit Payments [Line Items]
Distributions from existing plan assets	$ 48.4
Includes Plan No 1 and No 2 One Time Voluntary Lump Sum Offer \| Lump Sums Plan No. 2
Schedule of Pension and Other Postretirement Benefits Expected Benefit Payments [Line Items]
Distributions from existing plan assets	$ 2.0
Includes Plan No 1 and No 2 Single Lump Sum \| Lump Sums Plan No. 1
Schedule of Pension and Other Postretirement Benefits Expected Benefit Payments [Line Items]
Distributions from existing plan assets		$ 15.7
Includes Plan No 1 and No 2 Single Lump Sum \| Lump Sums Plan No. 2
Schedule of Pension and Other Postretirement Benefits Expected Benefit Payments [Line Items]
Distributions from existing plan assets		$ 1.6