Summary of Significant Accounting Policies Restricted Cash and Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Restricted Cash and Cash Equivalents Items
Restricted investments	$ 0	$ 430

Investments which are not defined as or included in marketable (debt, equity, or other) securities whose use is restricted in whole or in part, generally by contractual agreements or regulatory requirements. For use in an unclassified balance sheet.

No definition available.

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