Incremental Term Loan Facility Maximum Capacity

No definition available.

Name:	bwc_IncrementalTermLoanFacilityMaximumCapacity
Namespace Prefix:	bwc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line Of Credit Facility Draw Down Amount

+ References

No definition available.

+ Details

Name:	bwc_LineOfCreditFacilityDrawDownAmount
Namespace Prefix:	bwc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line Of Credit Facility Fee Percentage

+ References

No definition available.

+ Details

Name:	bwc_LineOfCreditFacilityFeePercentage
Namespace Prefix:	bwc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Quarterly amortization payments as percentage of aggregate principal amount of term loan.

+ References

No definition available.

+ Details

Name:	bwc_QuarterlyAmortizationPaymentsAsPercentageOfAggregatePrincipalAmountOfTermLoan
Namespace Prefix:	bwc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 2: 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

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Maximum contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentageRateRangeMaximum
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Minimum contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 2: 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

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentageRateRangeMinimum
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ References

No definition available.

+ Details

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Date the credit facility terminates, 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 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

Name:	us-gaap_LineOfCreditFacilityExpirationDate1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_LineOfCreditFacilityLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 16

-Article 7

Reference 2: 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)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.16)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 16

-Article 9

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 20, 22

-Article 5

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.16)

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

+ Details

Name:	us-gaap_LongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Credit Facility - Additional Information (Detail) (USD $)	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2014 Minimum [Member]	Jun. 30, 2014 Maximum [Member]	Jun. 30, 2014 Financial Letter of Credit [Member]	Jun. 30, 2014 Financial Letter of Credit [Member] Minimum [Member]	Jun. 30, 2014 Financial Letter of Credit [Member] Maximum [Member]	Jun. 30, 2014 Performance Letter Of Credit [Member]	Jun. 30, 2014 Performance Letter Of Credit [Member] Minimum [Member]	Jun. 30, 2014 Performance Letter Of Credit [Member] Maximum [Member]	Jun. 30, 2014 Eurocurrency Rate Loans [Member]	Jun. 30, 2014 Base Rate Loans [Member]	Jun. 30, 2014 Base Rate Loans [Member] Federal Funds Rate [Member]	Jun. 30, 2014 Base Rate Loans [Member] One Month Eurocurrency Rate [Member]	Jun. 30, 2014 Letter of Credit [Member]	Jun. 24, 2014 Letter of Credit [Member]	Jun. 30, 2014 Term Loan Credit Facility [Member]	Jun. 24, 2014 Term Loan Credit Facility [Member]	Jun. 30, 2014 Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Credit agreement, maximum borrowing capacity															$ 1,000,000,000		$ 300,000,000
Credit agreement, draw down amount																	150,000,000
Aggregate amount to be borrowed to meet letter of credit requirements														863,200,000			150,000,000
Credit facility maturity date	Jun. 24, 2019
Incremental term loan, maximum capacity																	400,000,000
Quarterly amortization payments on term loan as a percentage of aggregate principal amount	1.25%
Annual interest rate of loan outstanding under credit agreement										1.25%	0.25%
Annual interest rate of loan outstanding under credit agreement										2.00%	1.00%
Annual interest rate of loan outstanding under credit agreement										1.375%	0.375%	0.50%	1.00%
Commitment fee on unused portions of credit agreement, variable range	0.225%	0.20%	0.35%
Letter of credit fee on unused portions of credit agreement, variable range				1.375%	1.25%	2.00%	0.80%	0.725%	1.125%
Credit facility, aggregate borrowings outstanding																150,000,000		113,800,000
Aggregate amount borrowed by issuing letters of credit														$ 173,000,000