Other Income (Expense) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Other Income and Expenses [Abstract]
Interest income from investments in special purpose entities	$ 2,018	$ 0	$ 2,018	$ 0
Net investment income from available-for-sale securities	1,580	268	1,814	268
Interest accrued on notes receivable	353	38	392	145
Total investment income, net	3,951	306	4,224	413
Interest expense and amortization of discount and issuance costs for Senior Notes issued by special purpose entity	(2,071)	0	(2,071)	0
Interest expense	(178)	(269)	(818)	(868)
Total interest expense	(2,249)	(269)	(2,889)	(868)
Other, net	570	1,093	1,347	1,345
Total other income	$ 2,272	$ 1,130	$ 2,682	$ 890