Significant Accounting Policies Significant Accounting Policies (Subsequent Events) (Details) - USD ($) $ in Thousands	Oct. 01, 2016	Sep. 30, 2016	Dec. 31, 2015
Subsequent Event [Line Items]
Assets		$ 29,727,096	$ 28,792,653
Subsequent Event [Member] | Entaire Global Companies, Inc. (Entaire) [Member]
Subsequent Event [Line Items]
Assets	$ 370,000
Subsequent Event [Member] | Entaire Global Companies, Inc. (Entaire) [Member] | Loans Receivable [Member]
Subsequent Event [Line Items]
Assets	357,000
Subsequent Event [Member] | Entaire Global Companies, Inc. (Entaire) [Member]
Subsequent Event [Line Items]
Payments to acquire businesses	$ 30,000
Subsequent Event [Member] | Entaire Global Companies, Inc. (Entaire) [Member] | Minimum [Member]
Subsequent Event [Line Items]
Potential additional payments based on earnings, period	3 years
Subsequent Event [Member] | Entaire Global Companies, Inc. (Entaire) [Member] | Maximum [Member]
Subsequent Event [Line Items]
Potential additional payments based on earnings, period	5 years