Derivative Instruments - Derivatives Designated as Hedging Instruments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Interest Rate Contract
Fixed-rate subordinated notes, face amount	$ 150,000
Carrying amount of the hedged liability - Subordinated bank note - 2025	144,296	$ 146,095
Cumulative amount of fair value hedging adjustments included in the carrying amount of the hedged liability - Subordinated bank note - 2025	(4,165)	(2,157)
Gains and losses related to changes in the fair value of the interest rate swap and hedged debt
Total amount presented in the Consolidated Statements of Income - Interest expense - borrowings	43,144	27,807	$ 20,836
Total amount presented in the Consolidated Statements of Income - Other non-interest income	13,843	11,646	8,883
Summary of Net Investment Hedge Activity [Abstract]
Effect of net investment hedges on accumulated other comprehensive income	13,762	(4,430)	(1,213)
Derivatives designated as hedges | Net investment hedges | Forward foreign exchange contracts
Summary of Net Investment Hedge Activity [Abstract]
Effect of net investment hedges on accumulated other comprehensive income	13,762	(4,430)	(1,213)
Derivatives designated as hedges | Interest expense - borrowings
Gains and losses related to changes in the fair value of the interest rate swap and hedged debt
Gain (loss) of fair value hedge: Hedged item	2,163
Gain (loss) of fair value hedge: Derivatives designated as a hedging instrument	$ (2,275)
Derivatives designated as hedges | Other non-interest income
Gains and losses related to changes in the fair value of the interest rate swap and hedged debt
Gain (loss) of fair value hedge: Hedged item		808	1,140
Gain (loss) of fair value hedge: Derivatives designated as a hedging instrument		$ (609)	$ (1,178)