Cash Equivalent and Investments (Parenthetical)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Minimum [Member] | Certificates of Deposit [Member] | Short Term Investments [Member]
Schedule Of Investments [Line Items]
Securities maturity period	1 month	1 month
Minimum [Member] | Certificates of Deposit [Member] | Other Assets [Member]
Schedule Of Investments [Line Items]
Securities maturity period	1 month	1 month
Minimum [Member] | Fixed Maturity and Mutual Funds [Member]
Schedule Of Investments [Line Items]
Securities maturity period	11 months	2 months
Maximum [Member] | Major Types of Debt Securities [Domain] | Cash and Cash Equivalents [Member]
Schedule Of Investments [Line Items]
Securities maturity period	90 days
Maximum [Member] | Certificates of Deposit [Member] | Short Term Investments [Member]
Schedule Of Investments [Line Items]
Securities maturity period	12 months	10 months
Maximum [Member] | Certificates of Deposit [Member] | Other Assets [Member]
Schedule Of Investments [Line Items]
Securities maturity period	27 months	39 months
Maximum [Member] | Fixed Maturity and Mutual Funds [Member]
Schedule Of Investments [Line Items]
Securities maturity period	31 months	23 months