Related Party Transactions (Debt Agreements) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Related Party [Line Items]
Amount of Notes	$ 1,384,500
Amount of Notes		$ 1,384,000
Prudential Financial Loan Issued 12/15/2011
Related Party [Line Items]
Amount of Notes	$ 11,000
Amount of Notes		11,000
Interest Rate	3.61%
Prudential Financial Loan Issued 12/16/2011
Related Party [Line Items]
Amount of Notes	$ 11,000
Amount of Notes		11,000
Interest Rate	3.61%
Prudential Financial Loan Issued 11/15/2013
Related Party [Line Items]
Amount of Notes	$ 9,000
Amount of Notes		9,000
Interest Rate	2.24%
Prudential Financial Loan Issued 11/15/2013
Related Party [Line Items]
Amount of Notes	$ 23,000
Amount of Notes		23,000
Interest Rate	3.19%
Prudential Insurance Loan Issued 12/6/2013
Related Party [Line Items]
Amount of Notes	$ 120,000
Amount of Notes		120,000
Interest Rate	2.60%
Prudential Insurance Loan Issued 12/6/2013
Related Party [Line Items]
Amount of Notes	$ 130,000
Amount of Notes		130,000
Interest Rate	4.39%
Prudential Insurance Loan Issued 12/6/2013
Related Party [Line Items]
Amount of Notes	$ 250,000
Amount of Notes		250,000
Interest Rate	3.64%
Prudential Insurance Loan Issued 9/25/2014
Related Party [Line Items]
Amount of Notes	$ 30,000
Amount of Notes		30,000
Interest Rate	1.89%
Prudential Insurance Loan Issued 9/25/2014
Related Party [Line Items]
Amount of Notes	$ 40,000
Amount of Notes		40,000
Interest Rate	3.95%
Prudential Insurance Loan Issued 9/25/2014
Related Party [Line Items]
Amount of Notes	$ 20,000
Amount of Notes		20,000
Interest Rate	2.80%
Prudential Insurance Loan Issued 9/25/2014
Related Party [Line Items]
Amount of Notes	$ 50,000
Amount of Notes		50,000
Interest Rate	3.95%
Prudential Insurance Loan Issued 9/25/2014
Related Party [Line Items]
Amount of Notes	$ 50,000
Amount of Notes		50,000
Interest Rate	2.80%
Prudential Insurance Loan Issued 9/25/2014
Related Party [Line Items]
Amount of Notes	$ 100,000
Amount of Notes		100,000
Interest Rate	3.47%
Prudential Insurance Loan Issued 9/25/2014
Related Party [Line Items]
Amount of Notes	$ 100,000
Amount of Notes		100,000
Interest Rate	3.95%
Prudential Financial Loan Issued 12/15/2014
Related Party [Line Items]
Amount of Notes	$ 5,000
Amount of Notes		5,000
Interest Rate	2.57%
Prudential Financial Loan Issued 12/15/2014
Related Party [Line Items]
Amount of Notes	$ 23,000
Amount of Notes		23,000
Interest Rate	3.14%
Prudential Financial Loan Issued 6/15/2015
Related Party [Line Items]
Amount of Notes	$ 66,000
Amount of Notes		66,000
Interest Rate	3.52%
Prudential Financial Loan Issued 6/15/2015
Related Party [Line Items]
Amount of Notes	$ 6,000
Amount of Notes		6,000
Interest Rate	2.86%
Prudential Financial Loan Issued 9/21/2015
Related Party [Line Items]
Amount of Notes	$ 158,000
Amount of Notes		158,000
Prudential Financial Loan Issued 9/21/2015 | Minimum
Related Party [Line Items]
Interest Rate	1.09%
Prudential Financial Loan Issued 9/21/2015 | Maximum
Related Party [Line Items]
Interest Rate	1.63%
Prudential Financial Loan Issued 9/21/2015
Related Party [Line Items]
Amount of Notes	$ 132,000
Amount of Notes		132,000
Prudential Financial Loan Issued 9/21/2015 | Minimum
Related Party [Line Items]
Interest Rate	1.40%
Prudential Financial Loan Issued 9/21/2015 | Maximum
Related Party [Line Items]
Interest Rate	1.93%
Prudential Financial Loan Issued 9/21/2015
Related Party [Line Items]
Amount of Notes	$ 26,000
Amount of Notes		26,000
Prudential Financial Loan Issued 9/21/2015 | Minimum
Related Party [Line Items]
Interest Rate	1.40%
Prudential Financial Loan Issued 9/21/2015 | Maximum
Related Party [Line Items]
Interest Rate	1.93%
Prudential Financial Loan Issued 12/16/2015
Related Party [Line Items]
Amount of Notes	$ 5,000
Amount of Notes		5,000
Interest Rate	2.85%
Prudential Financial Loan Issued 12/16/2015
Related Party [Line Items]
Amount of Notes	$ 1,000
Amount of Notes		1,000
Interest Rate	2.85%
Prudential Financial Loan Issued 12/16/2015
Related Party [Line Items]
Amount of Notes	$ 18,000
Amount of Notes		18,000
Interest Rate	3.37%
Prudential Funding Loan Issued 3/31/2016
Related Party [Line Items]
Amount of Notes	$ 500
Amount of Notes		$ 0
Interest Rate	0.48%