Long-Term Debt - Outstanding Long-Term Debt (Detail) - USD ($) $ in Thousands		Jun. 30, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Total long-term debt		$ 159,900	$ 161,500
Capital Lease Obligations		5,483	6,130
Total Long-term debt		165,374	167,595
Less: current maturities		(9,127)	(9,109)
Total long-term debt, net of current maturities		156,247	158,486
9.08% bond, due June 1, 2022 [Member]
Debt Instrument [Line Items]
Total long-term debt	[1]	7,971	7,969
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		25,500	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.