Annual report pursuant to Section 13 and 15(d)

SEGMENT INFORMATION, MAJOR CUSTOMERS AND GEOGRAPHICAL DATA Schedule of Revenue from External Customers and Long-Lived Assets (Details)

v2.4.1.9
SEGMENT INFORMATION, MAJOR CUSTOMERS AND GEOGRAPHICAL DATA Schedule of Revenue from External Customers and Long-Lived Assets (Details) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 12 Months Ended
Dec. 31, 2014
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2014
Dec. 31, 2013
Sep. 30, 2013
Jun. 30, 2013
Mar. 31, 2013
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Operating revenues $ 74,689us-gaap_Revenues $ 90,510us-gaap_Revenues $ 86,580us-gaap_Revenues $ 79,443us-gaap_Revenues $ 75,998us-gaap_Revenues $ 80,997us-gaap_Revenues $ 74,237us-gaap_Revenues $ 67,727us-gaap_Revenues $ 331,222us-gaap_Revenues $ 298,959us-gaap_Revenues $ 272,921us-gaap_Revenues
Property and Equipment 863,126us-gaap_PropertyPlantAndEquipmentNet       803,652us-gaap_PropertyPlantAndEquipmentNet       863,126us-gaap_PropertyPlantAndEquipmentNet 803,652us-gaap_PropertyPlantAndEquipmentNet  
United States [Member]                      
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Operating revenues                 281,869us-gaap_Revenues
/ us-gaap_StatementGeographicalAxis
= country_US
245,581us-gaap_Revenues
/ us-gaap_StatementGeographicalAxis
= country_US
213,920us-gaap_Revenues
/ us-gaap_StatementGeographicalAxis
= country_US
Property and Equipment 639,852us-gaap_PropertyPlantAndEquipmentNet
/ us-gaap_StatementGeographicalAxis
= country_US
      579,509us-gaap_PropertyPlantAndEquipmentNet
/ us-gaap_StatementGeographicalAxis
= country_US
      639,852us-gaap_PropertyPlantAndEquipmentNet
/ us-gaap_StatementGeographicalAxis
= country_US
579,509us-gaap_PropertyPlantAndEquipmentNet
/ us-gaap_StatementGeographicalAxis
= country_US
 
Latin America and the Caribbean [Member]                      
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Operating revenues                 20,524us-gaap_Revenues
/ us-gaap_StatementGeographicalAxis
= era_LatinAmericaandtheCaribbeanMember
23,407us-gaap_Revenues
/ us-gaap_StatementGeographicalAxis
= era_LatinAmericaandtheCaribbeanMember
23,636us-gaap_Revenues
/ us-gaap_StatementGeographicalAxis
= era_LatinAmericaandtheCaribbeanMember
Property and Equipment 134,829us-gaap_PropertyPlantAndEquipmentNet
/ us-gaap_StatementGeographicalAxis
= era_LatinAmericaandtheCaribbeanMember
      130,844us-gaap_PropertyPlantAndEquipmentNet
/ us-gaap_StatementGeographicalAxis
= era_LatinAmericaandtheCaribbeanMember
      134,829us-gaap_PropertyPlantAndEquipmentNet
/ us-gaap_StatementGeographicalAxis
= era_LatinAmericaandtheCaribbeanMember
130,844us-gaap_PropertyPlantAndEquipmentNet
/ us-gaap_StatementGeographicalAxis
= era_LatinAmericaandtheCaribbeanMember
 
Europe [Member]                      
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Operating revenues                 17,914us-gaap_Revenues
/ us-gaap_StatementGeographicalAxis
= us-gaap_EuropeMember
22,008us-gaap_Revenues
/ us-gaap_StatementGeographicalAxis
= us-gaap_EuropeMember
25,749us-gaap_Revenues
/ us-gaap_StatementGeographicalAxis
= us-gaap_EuropeMember
Property and Equipment 70,134us-gaap_PropertyPlantAndEquipmentNet
/ us-gaap_StatementGeographicalAxis
= us-gaap_EuropeMember
      73,631us-gaap_PropertyPlantAndEquipmentNet
/ us-gaap_StatementGeographicalAxis
= us-gaap_EuropeMember
      70,134us-gaap_PropertyPlantAndEquipmentNet
/ us-gaap_StatementGeographicalAxis
= us-gaap_EuropeMember
73,631us-gaap_PropertyPlantAndEquipmentNet
/ us-gaap_StatementGeographicalAxis
= us-gaap_EuropeMember
 
Asia [Member]                      
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Operating revenues                 10,915us-gaap_Revenues
/ us-gaap_StatementGeographicalAxis
= us-gaap_AsiaMember
7,679us-gaap_Revenues
/ us-gaap_StatementGeographicalAxis
= us-gaap_AsiaMember
9,298us-gaap_Revenues
/ us-gaap_StatementGeographicalAxis
= us-gaap_AsiaMember
Property and Equipment 18,311us-gaap_PropertyPlantAndEquipmentNet
/ us-gaap_StatementGeographicalAxis
= us-gaap_AsiaMember
      19,349us-gaap_PropertyPlantAndEquipmentNet
/ us-gaap_StatementGeographicalAxis
= us-gaap_AsiaMember
      18,311us-gaap_PropertyPlantAndEquipmentNet
/ us-gaap_StatementGeographicalAxis
= us-gaap_AsiaMember
19,349us-gaap_PropertyPlantAndEquipmentNet
/ us-gaap_StatementGeographicalAxis
= us-gaap_AsiaMember
 
Canada [Member]                      
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Operating revenues                 0us-gaap_Revenues
/ us-gaap_StatementGeographicalAxis
= country_CA
284us-gaap_Revenues
/ us-gaap_StatementGeographicalAxis
= country_CA
318us-gaap_Revenues
/ us-gaap_StatementGeographicalAxis
= country_CA
Property and Equipment $ 0us-gaap_PropertyPlantAndEquipmentNet
/ us-gaap_StatementGeographicalAxis
= country_CA
      $ 319us-gaap_PropertyPlantAndEquipmentNet
/ us-gaap_StatementGeographicalAxis
= country_CA
      $ 0us-gaap_PropertyPlantAndEquipmentNet
/ us-gaap_StatementGeographicalAxis
= country_CA
$ 319us-gaap_PropertyPlantAndEquipmentNet
/ us-gaap_StatementGeographicalAxis
= country_CA