Long-Term Debt - Outstanding Long-Term Debt (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015		Dec. 31, 2014
Debt Instrument [Line Items]
Total long-term debt	$ 161,400		$ 161,500
Capital Lease Obligations	5,808		6,130
Total Long-term debt	167,199		167,595
Less: current maturities	(9,116)		(9,109)
Total long-term debt, net of current maturities	158,083		158,486
9.08% bond, due June 1, 2022 [Member]
Debt Instrument [Line Items]
Total long-term debt	7,971	[1]	7,969	[1]
6.64% note, due October 31, 2017 [Member]
Debt Instrument [Line Items]
Total long-term debt	8,182		8,182
5.50% note, due October 12, 2020 [Member]
Debt Instrument [Line Items]
Total long-term debt	12,000		12,000
5.93% note, due October 31, 2023 [Member]
Debt Instrument [Line Items]
Total long-term debt	27,000		27,000
5.68% note, due June 30, 2026 [Member]
Debt Instrument [Line Items]
Total long-term debt	29,000		29,000
Uncollateralized Senior Notes Due On May Two Thousand Twenty Eight [Member]
Debt Instrument [Line Items]
Total long-term debt	7,000		7,000
Uncollateralized Senior Note Two Due on December Two Thousand Twenty Eight [Member]
Debt Instrument [Line Items]
Total long-term debt	20,000		20,000
Uncollateralized Senior Notes Due On Two Thousand Twenty Nine [Member]
Debt Instrument [Line Items]
Total long-term debt	50,000		50,000
Promissory note [Member]
Debt Instrument [Line Items]
Total long-term debt	$ 238		$ 314

[1] FPU secured first mortgage bonds are guaranteed by Chesapeake.