RELATED PERSON TRANSACTIONS - Transactions With Controlling Shareholders (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Leased assets or facilities \| Entities owned by the controlling shareholders
Related person transactions
Amount paid	$ 5.1	$ 5.1	$ 5.2
Charter Aircraft [Member] \| Controlling shareholders
Related person transactions
Aircraft expense	$ 1.4	$ 1.5	$ 0.9

Expenses recognized resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Name:	us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration