Fair Value - Summary of Carrying Value and Fair Value of Company's Financial Instruments (Details) - USD ($) $ in Thousands		Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity		$ 372,498	$ 203,525
Loans, net		2,856,136	2,137,202
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity	[1]	0	0
Loans, net		0	0
Deposits		0	0
FHLB borrowings			0
Subordinated debt		0	0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity	[1]	369,881	202,813
Loans, net		0	0
Deposits		0	0
FHLB borrowings			51,788
Subordinated debt		54,908	52,785
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity	[1]	0	0
Loans, net		2,840,993	2,147,024
Deposits		3,523,322	2,843,800
FHLB borrowings			0
Subordinated debt		0	0
Carrying Amount [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity	[1]	372,498	203,525
Loans, net		2,852,016	2,129,691
Deposits		3,523,245	2,844,387
FHLB borrowings			50,000
Subordinated debt		$ 70,241	$ 69,961

[1] See Note D for further detail of recurring fair value basis of individual investment categories.