Investments in Affiliates, Net (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Schedule of Investments [Line Items]
Equity in earnings/(losses) of affiliates, net of tax	$ 78	$ 4,667	$ (11)	$ 8,434
Operating revenues from affiliates	2,700	5,200
Operating expenses with affiliates	2,900	3,100
Operating revenues	500,204	386,013	953,747	750,784
Operating expenses	$ 424,689	$ 325,306	820,922	$ 640,812
Maximum [Member]
Schedule of Investments [Line Items]
Equity in earnings/(losses) of affiliates, net of tax			(100)
RELS LLC [Member]
Schedule of Investments [Line Items]
Ownership percentage in joint venture					50.10%
Joint venture investment percentage of income in equity earnings of affiliates		85.90%		84.90%
Ownership percentage in affiliate		100.00%		100.00%
Joint Venture Loan Originations Products and Services [Member]
Schedule of Investments [Line Items]
Operating revenues			5,200	$ 9,400
Operating expenses			$ 5,500	$ 6,500