Derivative Financial Instruments (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2017	Dec. 31, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Aggregate fair value of derivative instruments with credit-risk-related contingent features, in case of net liability position	$ 49,235	$ 38,324
Collateral related to the derivatives	0	0
Fair value of assets required to settle the derivatives in, net liability position	49,235
Amount of unrestricted cash collateral to counterparties in the normal course of business	0	0
Cash collateral received	80,145	103,214
Net derivative gains estimated to be reclassified from accumulated other comprehensive income (loss) into net income within the next twelve months	10,436
Derivative financial instruments
Notional amount	4,992,157	2,396,297
Net derivatives, Fair value	89,532	108,104
Asset derivatives, Fair value	139,300	146,385
Liability derivatives, Fair value	49,768	38,281
Interest rate swaps
Derivative financial instruments
Average notional amount of the derivative instruments	897,400	784,900
Cross-currency swaps
Derivative financial instruments
Average notional amount of the derivative instruments	1,239,581	1,141,967
Other forward contracts
Derivative financial instruments
Average notional amount of the derivative instruments	1,545,788	2,230,167
Future
Derivative financial instruments
Average notional amount of the derivative instruments	114,425	145,658
Swaption
Derivative financial instruments
Average notional amount of the derivative instruments	163,232	156,632
Derivatives designated as hedges:
Derivative financial instruments
Notional amount	1,086,377	1,034,008
Net derivatives, Fair value	70,039	78,737
Asset derivatives, Fair value	80,960	87,031
Liability derivatives, Fair value	10,921	8,294
Derivatives designated as hedges: \| Cash flow hedges:
Derivative financial instruments
Notional amount	1,086,377	1,034,008
Net derivatives, Fair value	70,039	78,737
Asset derivatives, Fair value	80,960	87,031
Liability derivatives, Fair value	10,921	8,294
Derivatives designated as hedges: \| Cash flow hedges: \| Interest rate swaps
Derivative financial instruments
Notional amount	419,800	419,800
Net derivatives, Fair value	37,308	33,390
Asset derivatives, Fair value	37,308	33,390
Liability derivatives, Fair value	0	0
Derivatives designated as hedges: \| Cash flow hedges: \| Cross-currency swaps
Derivative financial instruments
Notional amount	666,577	614,208
Net derivatives, Fair value	32,731	45,347
Asset derivatives, Fair value	43,652	53,641
Liability derivatives, Fair value	10,921	8,294
Derivatives not designated as hedges:
Derivative financial instruments
Notional amount	3,905,780	1,362,289
Net derivatives, Fair value	19,493	29,367
Asset derivatives, Fair value	58,340	59,354
Liability derivatives, Fair value	38,847	29,987
Derivatives not designated as hedges: \| Interest rate swaps
Derivative financial instruments
Notional amount	486,100	468,100
Net derivatives, Fair value	(6,708)	(4,358)
Asset derivatives, Fair value	8,187	8,982
Liability derivatives, Fair value	14,895	13,340
Derivatives not designated as hedges: \| Cross-currency swaps
Derivative financial instruments
Notional amount	612,733	612,733
Net derivatives, Fair value	19,152	33,371
Asset derivatives, Fair value	42,071	50,018
Liability derivatives, Fair value	22,919	16,647
Derivatives not designated as hedges: \| Futures on equity indices
Derivative financial instruments
Notional amount	31,433	34,422
Net derivatives, Fair value	0	0
Asset derivatives, Fair value	0	0
Liability derivatives, Fair value	0	0
Derivatives not designated as hedges: \| Interest rate futures
Derivative financial instruments
Notional amount	74,600	81,500
Net derivatives, Fair value	0	0
Asset derivatives, Fair value	0	0
Liability derivatives, Fair value	0	0
Derivatives not designated as hedges: \| Interest rate swaptions
Derivative financial instruments
Notional amount	162,464	165,534
Net derivatives, Fair value	265	354
Asset derivatives, Fair value	265	354
Liability derivatives, Fair value	0	$ 0
Derivatives not designated as hedges: \| Other forward contracts
Derivative financial instruments
Notional amount	2,538,450
Net derivatives, Fair value	6,784
Asset derivatives, Fair value	7,817
Liability derivatives, Fair value	$ 1,033

Average notional amount specified by the derivative(s). Expressed as an absolute value.

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The estimated value of gains (losses), net anticipated to be transferred in the next twelve months from accumulated other comprehensive income into earnings.

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Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

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-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
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The aggregate fair value of assets needed to immediately settle the derivative instruments with credit-risk-related contingent features if the credit-risk-related contingent features were triggered at the end of the reporting period.

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The aggregate fair value of assets that are already posted, at the end of the reporting period, as collateral for derivative instruments with credit-risk-related contingent features.

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Amount of obligation to return cash collateral under master netting arrangements that have not been offset against derivative assets.

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Amount of right to receive cash collateral under master netting arrangements that have not been offset against derivative liabilities.

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Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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Fair value of the assets less the liabilities of a derivative or group of derivatives.

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The aggregate fair value amounts of derivative instruments that contain credit-risk-related contingent features that are in a net liability position at the end of the reporting period. For nonderivative instruments that are designated and qualify as hedging instruments, the fair value amounts are the carrying value of the nonderivative hedging instrument, including the adjustment for the foreign currency transaction gain (loss) on that instrument.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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