Lease Agreements - Future minimum rental payments under operating and capital leases (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013
Capital Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Capital leases minimum payments for 2014	$ 400
Capital leases minimum payments for 2015	395
Capital leases minimum payments for 2016	203
Capital leases minimum payments for 2017	0
Capital leases minimum payments for 2018	0
Capital leases minimum payments for later years	0
Capital leases minimum payments total	998
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Operating leases minimum payments for 2014	13,462
Operating leases minimum payments for 2015	11,734
Operating leases minimum payments for 2016	10,719
Operating leases minimum payments for 2017	9,191
Operating leases minimum payments for 2018	8,051
Operating leases minimum payments for later years	19,895
Operating leases minimum payments total	$ 73,052

Amount of minimum lease payments for capital leases.

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Amount of minimum lease payments maturing in the next fiscal year following the latest fiscal year for capital leases.

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Amount of minimum lease payments maturing in the fifth fiscal year following the latest fiscal year for capital leases.

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Amount of minimum lease payments maturing in the forth fiscal year following the latest fiscal year for capital leases.

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Amount of minimum lease payments maturing in the third fiscal year following the latest fiscal year for capital leases.

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Amount of minimum lease payments maturing in the second fiscal year following the latest fiscal year for capital leases.

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Amount of minimum lease payments maturing after the fifth fiscal year following the latest fiscal year for capital leases.

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Amount of required minimum rental payments for leases having an initial or remaining non-cancelable letter-terms in excess of one year.

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

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