Aggregate dividends declared during the period for each share of common stock outstanding.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

+ Details

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Namespace Prefix:	us-gaap_
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Balance Type:	na
Period Type:	duration

- Definition

Date the declared dividend will be paid, in CCYY-MM-DD format.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4304-108586

+ Details

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

- Definition

Date the dividend to be paid was declared, in CCYY-MM-DD format.

+ References

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
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- Definition

Date the holder must own the stock to be entitled to the dividend, in CCYY-MM-DD format.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
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Data Type:	xbrli:stringItemType
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Dividends Declared Per Share (Detail) (USD $)	3 Months Ended		9 Months Ended
Dividends Declared Per Share (Detail) (USD $)	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Dividends Payable [Line Items]
Dividend Amount	$ 0.345	$ 0.345	$ 1.035	$ 1.380
Group One
Dividends Payable [Line Items]
Declaration Date			Oct. 21, 2014
Date Paid (Payable)			Nov. 28, 2014
Shareholder of Record Date			Nov. 14, 2014
Dividend Amount			$ 0.345
Group Two
Dividends Payable [Line Items]
Declaration Date			Jul. 22, 2014
Date Paid (Payable)			Aug. 29, 2014
Shareholder of Record Date			Aug. 15, 2014
Dividend Amount			$ 0.345
Group Three
Dividends Payable [Line Items]
Declaration Date			Apr. 22, 2014
Date Paid (Payable)			May 29, 2014
Shareholder of Record Date			May 15, 2014
Dividend Amount			$ 0.345
Group Four
Dividends Payable [Line Items]
Declaration Date			Jan. 16, 2014
Date Paid (Payable)			Feb. 28, 2014
Shareholder of Record Date			Feb. 14, 2014
Dividend Amount			$ 0.345
Group Five
Dividends Payable [Line Items]
Declaration Date			Sep. 18, 2013
Date Paid (Payable)			Nov. 15, 2013
Shareholder of Record Date			Nov. 01, 2013
Dividend Amount			$ 0.345
Group Six
Dividends Payable [Line Items]
Declaration Date			Jun. 05, 2013
Date Paid (Payable)			Aug. 15, 2013
Shareholder of Record Date			Aug. 01, 2013
Dividend Amount			$ 0.345
Group Seven
Dividends Payable [Line Items]
Declaration Date			Mar. 28, 2013
Date Paid (Payable)			May 15, 2013
Shareholder of Record Date			May 01, 2013
Dividend Amount			$ 0.345
Group Eight
Dividends Payable [Line Items]
Declaration Date			Jan. 17, 2013
Date Paid (Payable)			Feb. 15, 2013
Shareholder of Record Date			Feb. 01, 2013
Dividend Amount			$ 0.345