Significant Accounting Policies, Consolidation of Variable Interest Entities (Details) $ in Millions	6 Months Ended	12 Months Ended
Jun. 30, 2015 USD ($) Entity	Dec. 31, 2014 Entity
Consolidation of variable interest entities [Abstract]
Number of variable interest entities in which the entity is not primary beneficiary	2	2
Carrying value of investments in variable interest entities \| $	$ 60.6

Carrying amount of the assets in the reporting entity's statement of financial position that relate to the reporting entity's variable interest in the Variable Interest Entity (VIE), where the reporting entity is not the VIE's primary beneficiary.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 50

-Paragraph 4

-Subparagraph a

-URI http://asc.fasb.org/extlink&oid=28200181&loc=d3e5728-111685

Name:	us-gaap_VariableInterestEntityNonconsolidatedCarryingAmountAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant