Variable Interest Entities - Carrying Amounts and Classification of Significant Variable Interests (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2015
Variable Interest Entity [Line Items]
Cash and cash equivalents	$ 3,795,679	$ 2,545,750	$ 1,868,512	$ 1,503,257
Non-marketable and other securities	635,550	622,552
Amortization Method Qualified Affordable Housing Project Investments	132,766	112,447	112,400
Accrued interest receivable and other assets	675,783	672,688
Total assets	46,413,339	44,683,660
Total liabilities	42,509,883	40,906,623
Maximum exposure to loss in unconsolidated VIEs	326,169	314,810
Qualified Affordable Housing Project Investments, Commitment	81,650	58,095	$ 58,095
Consolidated
Variable Interest Entity [Line Items]
Cash and cash equivalents	10,959	11,469
Non-marketable and other securities	196,708	196,140
Accrued interest receivable and other assets	236	294
Total assets	207,903	207,903
Total liabilities	387	517
Maximum exposure to loss in unconsolidated VIEs	207,500
Accrued Liabilities and Other Liabilities	387	517
Unconsolidated
Variable Interest Entity [Line Items]
Cash and cash equivalents	0	0
Non-marketable and other securities	326,169	314,810
Accrued interest receivable and other assets	0	0
Total assets	326,169	314,810
Total liabilities	$ 81,650	$ 58,095