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Secured Financing Agreements - Principal Repayments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Repayment of secured financings
Total	$ 2,073,229		$ 2,053,229
Secured financing agreements
Repayment of secured financings
2017 (remainder of)	539,009
2018	1,187,950
2019	537,914
2020	617,441
2021	442,273
Thereafter	1,131,760
Total	4,456,347		$ 4,197,218
Amortization of deferred financing costs from secured financing agreements included in interest expense	4,700	$ 3,900
Repurchase Agreements
Repayment of secured financings
2017 (remainder of)	518,557
2018	1,136,466
2019	490,476
2020	290,722
2021	126,586
Thereafter	154,235
Total	2,717,042
Other Secured Financing
Repayment of secured financings
2017 (remainder of)	20,452
2018	51,484
2019	47,438
2020	326,719
2021	315,687
Thereafter	977,525
Total	$ 1,739,305