Securities - Schedule of Fair Values and Gross Unrealized and Unrecognized Losses on Investments (Detail) $ in Thousands	Dec. 31, 2020 USD ($) Security	Jun. 30, 2020 USD ($) Security
Schedule Of Available For Sale Securities [Line Items]
Less than 12 Months: Fair Value	$ 231,033	$ 242,540
Less than 12 Months: Unrealized Losses	1,229	5,443
12 Months or More: Fair Value	193,649	190,737
12 Months or More: Unrealized Losses	$ 1,413	$ 5,264
Number of Securities | Security	41	45
Total: Fair Value	$ 424,682	$ 433,277
Total: Unrealized Losses	2,642	10,707
Debt Securities [Member] | Trust Preferred Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
12 Months or More: Fair Value	2,866	2,626
12 Months or More: Unrealized Losses	$ 101	$ 340
Number of Securities | Security	2	2
Total: Fair Value	$ 2,866	$ 2,626
Total: Unrealized Losses	101	340
Debt Securities [Member] | Asset-backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Less than 12 Months: Fair Value	46,989	146,494
Less than 12 Months: Unrealized Losses	529	3,962
12 Months or More: Fair Value	44,103	25,954
12 Months or More: Unrealized Losses	$ 438	$ 1,004
Number of Securities | Security	10	16
Total: Fair Value	$ 91,092	$ 172,448
Total: Unrealized Losses	967	4,966
Debt Securities [Member] | Collateralized Loan Obligations [Member]
Schedule Of Available For Sale Securities [Line Items]
Less than 12 Months: Fair Value	61,440	71,282
Less than 12 Months: Unrealized Losses	110	1,245
12 Months or More: Fair Value	126,755	122,506
12 Months or More: Unrealized Losses	$ 799	$ 3,586
Number of Securities | Security	18	19
Total: Fair Value	$ 188,195	$ 193,788
Total: Unrealized Losses	909	4,831
Debt Securities [Member] | Corporate Bonds [Member]
Schedule Of Available For Sale Securities [Line Items]
Less than 12 Months: Fair Value	41,548	24,764
Less than 12 Months: Unrealized Losses	401	236
12 Months or More: Fair Value	19,925	39,651
12 Months or More: Unrealized Losses	$ 75	$ 334
Number of Securities | Security	7	8
Total: Fair Value	$ 61,473	$ 64,415
Total: Unrealized Losses	476	$ 570
Debt Securities [Member] | Commercial Pass-Through Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Less than 12 Months: Fair Value	81,056
Less than 12 Months: Unrealized Losses	$ 189
Number of Securities | Security	4
Total: Fair Value	$ 81,056
Total: Unrealized Losses	$ 189