Goodwill and Other Intangible Assets (Details) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Net goodwill
Acquired goodwill	$ 635,900,000us-gaap_GoodwillAcquiredDuringPeriod	$ 642,600,000us-gaap_GoodwillAcquiredDuringPeriod
Customer-Relationship Intangibles
Gross Carrying Amount	94,330,000	94,330,000
Accumulated Amortization	(59,499,000)	(53,709,000)
Net Carrying Amount	34,831,000us-gaap_FiniteLivedIntangibleAssetsNet	40,621,000us-gaap_FiniteLivedIntangibleAssetsNet
Core deposit intangibles
Customer-Relationship Intangibles
Gross Carrying Amount	27,710,000	27,710,000
Accumulated Amortization	(27,249,000)	(25,967,000)
Net Carrying Amount	461,000	1,743,000
Client advisory contract
Customer-Relationship Intangibles
Gross Carrying Amount	64,433,000	64,433,000
Accumulated Amortization	(31,417,000)	(27,117,000)
Net Carrying Amount	33,016,000	37,316,000
Other client service contracts
Customer-Relationship Intangibles
Gross Carrying Amount	2,187,000	2,187,000
Accumulated Amortization	(833,000)	(625,000)
Net Carrying Amount	$ 1,354,000	$ 1,562,000

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

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- Definition

Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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- Definition

Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

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