Business Combinations - Summary of Assets Acquired and Liabilities Assumed and Their Initial Fair Value Estimates (Details) - USD ($) $ in Thousands	Jan. 01, 2020	Jun. 30, 2021	Dec. 31, 2020
Assets acquired:
Bank owned life insurance		$ 259,608	$ 265,253
Liabilities assumed:
Goodwill recorded in the merger		500,319	$ 500,319
Two River Bancorp Inc.
Estimated Fair Value
Total purchase price:	$ 197,050
Assets acquired:
Cash and cash equivalents	51,102
Securities	64,381
Loans	940,072
Accrued interest receivable	2,382
Bank owned life insurance	22,440
Deferred tax assets, net	3,158
Other assets	15,956
Core deposit intangible	12,130	12,100
Total assets acquired	1,111,621
Liabilities assumed:
Deposits	(941,750)
Other liabilities	(59,026)
Total liabilities assumed	(1,000,776)
Net assets acquired	110,845
Goodwill recorded in the merger	86,205
Country Bank Holding Company, Inc
Estimated Fair Value
Total purchase price:	112,836
Assets acquired:
Cash and cash equivalents	20,799
Securities	144,499
Loans	618,408
Accrued interest receivable	1,779
Deferred tax assets, net	(3,117)
Other assets	9,195
Core deposit intangible	2,117	$ 2,100
Total assets acquired	793,680
Liabilities assumed:
Deposits	(652,653)
Other liabilities	(67,240)
Total liabilities assumed	(719,893)
Net assets acquired	73,787
Goodwill recorded in the merger	$ 39,049