Disclosures About Fair Value of Financial Instruments - Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Financial assets:
Available-for-sale securities	$ 555,632	$ 274,619
Level 1
Financial assets:
Available-for-sale securities	145,422	112,881
Level 2
Financial assets:
Available-for-sale securities	410,210	161,738
Recurring [Member]
Financial assets:
Available-for-sale securities	555,632	274,619
Recurring [Member] | Interest Rate Swap
Financial assets:
Derivative asset		698
Recurring [Member] | Interest Rate Cap
Financial assets:
Derivative asset		1,307
Financial Liabilities:
Derivative liability		1,389
Recurring [Member] | Level 1
Financial assets:
Available-for-sale securities	145,422	112,881
Recurring [Member] | Level 2
Financial assets:
Available-for-sale securities	410,210	161,738
Recurring [Member] | Level 2 | Interest Rate Swap
Financial assets:
Derivative asset		698
Recurring [Member] | Level 2 | Interest Rate Cap
Financial assets:
Derivative asset		1,307
Financial Liabilities:
Derivative liability		1,389
Commercial Customer | Recurring [Member] | Interest Rate Swap
Financial assets:
Derivative asset	932
Financial Liabilities:
Derivative liability	932
Commercial Customer | Recurring [Member] | Interest Rate Cap
Financial assets:
Derivative asset	905
Financial Liabilities:
Derivative liability	104	5
Commercial Customer | Recurring [Member] | Level 2 | Interest Rate Swap
Financial assets:
Derivative asset	932
Financial Liabilities:
Derivative liability	932	698
Commercial Customer | Recurring [Member] | Level 2 | Interest Rate Cap
Financial assets:
Derivative asset	905
Financial Liabilities:
Derivative liability	104	5
Correspondent | Recurring [Member] | Interest Rate Cap
Financial assets:
Derivative asset	104	5
Financial Liabilities:
Derivative liability	958
Correspondent | Recurring [Member] | Level 2 | Interest Rate Cap
Financial assets:
Derivative asset	104	$ 5
Financial Liabilities:
Derivative liability	$ 958