Loan Servicing - Narrative (Details) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Servicing Assets at Fair Value [Line Items]
Mortgage Servicing Rights Fair Value	$ 9,057,000prk_MortgageServicingRightsFairValue	$ 9,546,000prk_MortgageServicingRightsFairValue
Transfers and Servicing of Financial Assets [Abstract]
Serviced sold mortgage loans	1,265,000,000	1,326,000,000	1,311,000,000
Serviced sold mortgage loans with recourse	7,000,000	10,700,000
Mortgage loans sold with recourse, reserve	379,000	1,000,000
Mortgage servicing rights, discount rate	10.00%	10.00%
Servicing fees included in other service income	$ 3,500,000us-gaap_ServicingFeesNet	$ 3,600,000us-gaap_ServicingFeesNet	$ 3,600,000us-gaap_ServicingFeesNet
Minimum
Transfers and Servicing of Financial Assets [Abstract]
Mortgage servicing rights, constant prepayment speeds	5.70%	6.60%
Maximum
Transfers and Servicing of Financial Assets [Abstract]
Mortgage servicing rights, constant prepayment speeds	22.30%	22.50%

Mortgage Loans Sold with Recourse, Reserve

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- Definition

Mortgage Servicing Rights Fair Value

+ References

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- Definition

Principal Amount Outstanding On Sold Loans Servicing Retained

+ References

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- Definition

Principal Amount Outstanding On Sold Loans Servicing Retained With Recourse

+ References

No definition available.

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- Definition

Estimated rate of prepayment of principal on financial assets for initial fair value measurement.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 20

-Section 50

-Paragraph 3

-Subparagraph (c)(2)

-URI http://asc.fasb.org/extlink&oid=13989330&loc=d3e107207-111719

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- Definition

Discount rate used to estimate the fair value of servicing assets and servicing liabilities.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 50

-Section 50

-Paragraph 2

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=7882072&loc=d3e122596-111746

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- Definition

Amount of revenue from servicing real estate mortgages, credit cards, and other financial assets held by others. Includes premiums received in lieu of regular servicing fees.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 13

-Article 9

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-04.13 (d))

-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

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