Summary of Significant Accounting Policies - Additional Information (Details) |
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2015
USD ($)
$ / participant
|
Dec. 31, 2014
USD ($)
|
Dec. 31, 2013
USD ($)
|
|
| Accounting Policies [Abstract] | |||
| Maximum exposure, per participant | $ / participant | 100,000 | ||
| Restricted cash, noncurrent | $ 13,515,000 | $ 16,165,000 | |
| Interest costs capitalized | 941,000 | 518,000 | $ 1,825,000 |
| Proceeds from Section 1603 grants | 0 | 3,727,000 | $ 3,262,000 |
| Deferred grant income | 8,291,000 | 8,842,000 | |
| Rebates from utility company | 0 | $ 0 | |
| Carrying value of fixed-rate long-term debt in excess of fair value | $ 1,175,000 | ||
| X | ||||||||||
- Definition Long-term Debt, Carrying Value in Excess of Fair Value No definition available.
|
| X | ||||||||||
- Definition Loss Contingency, Self Insurance, Maximum Exposure, Per Participant No definition available.
|
| X | ||||||||||
- Definition Proceeds from Government Grants No definition available.
|
| X | ||||||||||
- Definition Rebates from Utility Company No definition available.
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Amount of interest capitalized during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Carrying amount as of the balance sheet date of unearned revenue or income not otherwise specified in the taxonomy which is expected to be taken into income after one year or beyond the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Cash and equivalents whose use in whole or in part is restricted for the long-term, generally by contractual agreements or regulatory requirements. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|