The total cost of the acquired entity including the cash paid to shareholders of acquired entities, fair value of debt and equity securities issued to shareholders of acquired entities, the fair value of the liabilities assumed, and direct costs of the acquisition.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141

-Paragraph 51

-Subparagraph d

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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- Definition

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

+ References

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=6959260&loc=d3e187085-122770

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- Definition

Equity impact of common stock cash dividends declared by an entity during the period. This element includes paid and unpaid dividends declared during the period.

+ References

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- Definition

The amount authorized by an entity's Board of Directors under a stock repurchase plan.

+ References

No definition available.

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Subsequent Events (Details) (USD $)	3 Months Ended								12 Months Ended			1 Months Ended
Subsequent Events (Details) (USD $)	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Jan. 31, 2012 Dividend declared, February 2012	Jan. 31, 2012 Common stock repurchase	Jan. 31, 2012 Acquisition S&P Clever
Subsequent Events
Cash dividends declared per common share (in dollars per share)	$ 0.125	$ 0.125	$ 0.125	$ 0.125	$ 0.10	$ 0.10	$ 0.10	$ 0.10	$ 0.50	$ 0.40	$ 0.40	$ 0.125
Cash dividend declared									$ 24,336,000	$ 19,838,000	$ 19,674,000	$ 6,000,000
Common stock repurchase, authorized amount													50,000,000
Cost of acquired entity														$ 56,500,000