Leases (Details)	3 Months Ended
Mar. 31, 2019 yr
Lease Disclosure [Abstract]
Effect of CPI Basis Point Change	100
Minimum Renewal Term Length in Years - Lessee	1
Maximum Renewal Term Length in Years - Lessee	25

[Table Text Block] for Effect of CPI Basis Point Change [Table]

No definition available.

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Namespace Prefix:	cpk_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration