Leases (Summary of Total Lease Cost) (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Leases
Operating lease cost	$ 83,195	$ 78,814
Short-term operating lease cost	1,784	2,058
Variable operating lease cost	20,333	18,378
Sublease income	(1,175)	(957)
Total lease cost	$ 104,137	$ 98,293

Amount of lease cost recognized by lessee for lease contract.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980

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- References

No definition available.

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- Definition

Amount of single lease cost, calculated by allocation of remaining cost of lease over remaining lease term. Includes, but is not limited to, single lease cost, after impairment of right-of-use asset, calculated by amortization of remaining right-of-use asset and accretion of lease liability.

+ References

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-Publisher FASB
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- Definition

Amount of short-term lease cost, excluding expense for lease with term of one month or less.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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- Definition

Amount of sublease income excluding finance and operating lease expense.

+ References

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- Definition

Amount of variable lease cost, excluded from lease liability, recognized when obligation for payment is incurred for finance and operating leases.

+ References

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