EMPLOYEE BENEFIT PLANS Employer plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Participation in the multiemployer pension plans
Contributions by Global Power	$ 8,725	$ 16,419	$ 14,478
AFL-AGC Building Trades Pension Fund
Participation in the multiemployer pension plans
EIN/Pension Plan Number	636055108
Multiemployer Plans, Certified Zone Status	Green	Green	Green
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	No
Contributions by Global Power	$ 15	$ 224	$ 135
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Jul. 31, 2020
Asbestos Workers Local No. 55 Pension Fund
Participation in the multiemployer pension plans
EIN/Pension Plan Number	630474674
Multiemployer Plans, Certified Zone Status	Other	Green	Other
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	No
Contributions by Global Power	$ 1	$ 125	$ 96
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Jul. 31, 2020
Boilermaker-Blacksmith National Pension Trust
Participation in the multiemployer pension plans
EIN/Pension Plan Number	486168020
Multiemployer Plans, Certified Zone Status	Other	Other	Other
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	Implemented
Contributions by Global Power	$ 1,113	$ 2,729	$ 3,227
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Dec. 31, 2016
Bricklayers and Allied Craftworkers local #2 Albany, NY Pension Fund
Participation in the multiemployer pension plans
EIN/Pension Plan Number	146075802
Multiemployer Plans, Certified Zone Status	Green	Green	Green
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	No
Contributions by Global Power	$ 0	$ 0	$ 2
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Aug. 17, 2016
Carpenters Pension Trust Fund - Detroit & Vicinity
Participation in the multiemployer pension plans
EIN/Pension Plan Number	386242188
Multiemployer Plans, Certified Zone Status	Other	Other	Other
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	Implemented
Contributions by Global Power	$ 0	$ 0	$ 13
Central New York Laborers Pension Fund
Participation in the multiemployer pension plans
EIN/Pension Plan Number	156016579
Multiemployer Plans, Certified Zone Status	Other	Other	Other
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	Implemented
Contributions by Global Power	$ 0	$ 0	$ 224
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Aug. 17, 2016
Central New York Painters & Allied Trades Pension Fund
Participation in the multiemployer pension plans
EIN/Pension Plan Number	516079700
Multiemployer Plans, Certified Zone Status	Other	Other	Other
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	Implemented
Contributions by Global Power	$ 1	$ 4	$ 14
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Aug. 17, 2016
Central Pension Fund of the IUOE and Participating Employers
Participation in the multiemployer pension plans
EIN/Pension Plan Number	366052390
Multiemployer Plans, Certified Zone Status	Green	Green	Green
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	No
Contributions by Global Power	$ 143	$ 253	$ 378
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Dec. 31, 2016
Central States, Southeast, and Southwest Pension Fund
Participation in the multiemployer pension plans
EIN/Pension Plan Number	366044243
Multiemployer Plans, Certified Zone Status	Other	Other	Other
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	Implemented
Contributions by Global Power	$ 107	$ 252	$ 248
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Dec. 31, 2016
Chicago Painters & Decorators Pension Fund
Participation in the multiemployer pension plans
EIN/Pension Plan Number	516030238
Multiemployer Plans, Certified Zone Status	Green	Green	Green
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	No
Contributions by Global Power	$ 0	$ 0	$ 9
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Oct. 02, 2016
Empire State Carpenters Pension Plan
Participation in the multiemployer pension plans
EIN/Pension Plan Number	111991772
Multiemployer Plans, Certified Zone Status	Green	Green	Green
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	No
Contributions by Global Power	$ 0	$ 8	$ 158
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Aug. 17, 2016
Excavators Union Local 731 Pension Fund
Participation in the multiemployer pension plans
EIN/Pension Plan Number	131809825
Multiemployer Plans, Certified Zone Status	Green	Green	Green
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	No
Contributions by Global Power	$ 273	$ 217	$ 210
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Jun. 30, 2016
IBEW Local 1579 Pension Plan
Participation in the multiemployer pension plans
EIN/Pension Plan Number	581254974
Multiemployer Plans, Certified Zone Status	Green	Green	Green
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	No
Contributions by Global Power	$ 459	$ 700	$ 710
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Jul. 31, 2020
IBEW Local 43 & Electrical Contractors Pension
Participation in the multiemployer pension plans
EIN/Pension Plan Number	166153389
Multiemployer Plans, Certified Zone Status	Green	Other	Other
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	Implemented
Contributions by Global Power	$ 0	$ 0	$ 61
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Aug. 17, 2016
IBEW Local Union No. 1392 Pension Fund
Participation in the multiemployer pension plans
EIN/Pension Plan Number	356244875
Multiemployer Plans, Certified Zone Status	Green	Green	Green
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	No
Contributions by Global Power	$ 0	$ 0	$ 0
Insulators Local No. 96 Pension Plan
Participation in the multiemployer pension plans
EIN/Pension Plan Number	586110889
Multiemployer Plans, Certified Zone Status	Other	Other	Other
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	Implemented
Contributions by Global Power	$ 24	$ 170	$ 258
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Jul. 31, 2020
Iron Workers District Council of Tennessee Valley & Vicinity Pension Plan
Participation in the multiemployer pension plans
EIN/Pension Plan Number	626098036
Multiemployer Plans, Certified Zone Status	Other	Green	Green
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	No
Contributions by Global Power	$ 234	$ 261	$ 93
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Nov. 30, 2016
Iron Workers Local No. 16 Pension Fund
Participation in the multiemployer pension plans
EIN/Pension Plan Number	526148924
Multiemployer Plans, Certified Zone Status	Other	Other	Other
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	Implemented
Contributions by Global Power	$ 0	$ 0	$ 0
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Oct. 02, 2016
IUPAT Industry Pension Plan
Participation in the multiemployer pension plans
EIN/Pension Plan Number	526073909
Multiemployer Plans, Certified Zone Status	Other	Other	Other
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	Implemented
Contributions by Global Power	$ 1,374	$ 1,550	$ 1,438
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Dec. 31, 2016
Laborers National Pension Fund
Participation in the multiemployer pension plans
EIN/Pension Plan Number	751280827
Multiemployer Plans, Certified Zone Status	Green	Green	Green
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	No
Contributions by Global Power	$ 466	$ 1,025	$ 1,292
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Dec. 31, 2016
Local 73 Retirement Fund
Participation in the multiemployer pension plans
EIN/Pension Plan Number	156016577
Multiemployer Plans, Certified Zone Status	Other	Other	Other
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	Implemented
Contributions by Global Power	$ 0	$ 5	$ 276
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Aug. 17, 2016
National Asbestos Workers Pension Plan
Participation in the multiemployer pension plans
EIN/Pension Plan Number	526038497
Multiemployer Plans, Certified Zone Status	Other	Other	Other
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	Implemented
Contributions by Global Power	$ 1,548	$ 2,065	$ 1,438
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Dec. 31, 2016
National Electrical Benefits Fund
Participation in the multiemployer pension plans
EIN/Pension Plan Number	530181657
Multiemployer Plans, Certified Zone Status	Green	Green	Green
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	No
Contributions by Global Power	$ 365	$ 945	$ 477
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Dec. 31, 2016
New York State Teamsters Conference Pension & Retirement Fund
Participation in the multiemployer pension plans
EIN/Pension Plan Number	166063585
Multiemployer Plans, Certified Zone Status	Other	Other	Other
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	Implemented
Contributions by Global Power	$ 0	$ 0	$ 18
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Aug. 17, 2016
Northwest Sheet Metal Workers Pension Trust
Participation in the multiemployer pension plans
EIN/Pension Plan Number	916061344
Multiemployer Plans, Certified Zone Status	Green	Green	Green
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	No
Contributions by Global Power	$ 31	$ 104	$ 30
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Nov. 01, 2016
Plumbers & Pipefitters National Pension Fund
Participation in the multiemployer pension plans
EIN/Pension Plan Number	526152779
Multiemployer Plans, Certified Zone Status	Other	Other	Other
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	Implemented
Contributions by Global Power	$ 496	$ 866	$ 609
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Dec. 31, 2016
Plumbers & Steamfitters Local No. 150 Pension Fund
Participation in the multiemployer pension plans
EIN/Pension Plan Number	586116699
Multiemployer Plans, Certified Zone Status	Green	Green	Other
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	No
Contributions by Global Power	$ 98	$ 168	$ 415
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Jul. 31, 2020
Plumber & Steamfitters Local Union No. 43 Pension Fund
Participation in the multiemployer pension plans
EIN/Pension Plan Number	626101288
Multiemployer Plans, Certified Zone Status	Green	Green	Green
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	No
Contributions by Global Power	$ 295	$ 861	$ 251
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Nov. 30, 2016
Sheet Metal Workers Local No. 177 Pension Fund
Participation in the multiemployer pension plans
EIN/Pension Plan Number	626093256
Multiemployer Plans, Certified Zone Status	Green	Green	Green
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	No
Contributions by Global Power	$ 51	$ 91	$ 69
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Nov. 30, 2016
Sheet Metal Workers' National Pension Fund
Participation in the multiemployer pension plans
EIN/Pension Plan Number	526112463
Multiemployer Plans, Certified Zone Status	Other	Other	Other
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	Implemented
Contributions by Global Power	$ 232	$ 540	$ 423
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Dec. 31, 2016
Southern Ironworkers Pension Plan
Participation in the multiemployer pension plans
EIN/Pension Plan Number	596227091
Multiemployer Plans, Certified Zone Status	Green	Green	Green
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	No
Contributions by Global Power	$ 71	$ 211	$ 244
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Jul. 31, 2020
Tri-State Carpenters & Joiners Pension Trust Fund
Participation in the multiemployer pension plans
EIN/Pension Plan Number	620976048
Multiemployer Plans, Certified Zone Status	Other	Other	Other
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	Implemented
Contributions by Global Power	$ 522	$ 1,236	$ 1,146
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Nov. 30, 2016
Pipe Trades Services of MN Pension Plan
Participation in the multiemployer pension plans
EIN/Pension Plan Number	416131800
Multiemployer Plans, Certified Zone Status	Green	Green	Green
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	No
Contributions by Global Power	$ 0	$ 153	$ 0
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Aug. 01, 2016
Upstate New York Engineers Benefit Funds
Participation in the multiemployer pension plans
EIN/Pension Plan Number	150614642
Multiemployer Plans, Certified Zone Status	Other	Other	Other
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	Implemented
Contributions by Global Power	$ 0	$ 0	$ 26
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Aug. 17, 2016
Washington State Plumbing & Pipefitting Industry Pension Plan
Participation in the multiemployer pension plans
EIN/Pension Plan Number	916029141
Multiemployer Plans, Certified Zone Status	Green	Green	Green
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	No
Contributions by Global Power	$ 47	$ 251	$ 33
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Nov. 01, 2016
Washington-Idaho Laborers-Employers Pension Trust
Participation in the multiemployer pension plans
EIN/Pension Plan Number	916123988
Multiemployer Plans, Certified Zone Status	Green	Green	Green
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	No
Contributions by Global Power	$ 47	$ 204	$ 41
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Nov. 01, 2016
Washington-Idaho-Montana Carpenters-Employers Retirement Fund
Participation in the multiemployer pension plans
EIN/Pension Plan Number	916123987
Multiemployer Plans, Certified Zone Status	Other	Other	Other
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	Implemented
Contributions by Global Power	$ 85	$ 524	$ 99
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Nov. 01, 2016
Western States Insulators and Allied Workers Pension
Participation in the multiemployer pension plans
EIN/Pension Plan Number	510155190
Multiemployer Plans, Certified Zone Status	Green	Green	Green
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan	No
Contributions by Global Power	$ 22	$ 143	$ 26
Multiemployer Plans, Collective-Bargaining Arrangement, Expiration Date	Nov. 01, 2016
All Others
Participation in the multiemployer pension plans
Contributions by Global Power	$ 605	$ 534	$ 291
Minimum
Participation in the multiemployer pension plans
Individual union CBA range	1 year
Percentage of contributions to plan provided by Global Power	5.00%
Minimum | IBEW Local Union No. 1392 Pension Fund
Participation in the multiemployer pension plans
Percentage of contributions to plan provided by Global Power	5.00%
Maximum
Participation in the multiemployer pension plans
Individual union CBA range	3 years