Income Taxes - Schedule of Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Increase (reduction) in income tax resulting from:
Income tax expense at statutory rate									$ 21,961	$ 30,281	$ 26,194
Tax-exempt income, net									(506)	(961)	(945)
State and local income taxes, net									2,423	1,676	1,673
Bank-owned life insurance, net									(452)	(715)	(544)
Non-deductible expenses									294	407	263
Change in estimated rate for deferred taxes									0	12,117	302
Tax benefits of LIHTC investments, net									(50)	(257)	(181)
Other, net									676	(379)	(698)
Effective Income Tax Rate Reconciliation, Tax Credit, Amount									(1,631)	(2,141)	0
Effective Income Tax Rate Reconciliation, Tax Credit, Other, Amount									(4,627)	(1,701)	(62)
Non-taxable subsidiary dividend									(2,728)	0	0
Total income tax expense	$ 4,899	$ 1,802	$ 4,881	$ 3,778	$ 19,820	$ 7,856	$ 5,545	$ 5,106	$ 15,360	$ 38,327	$ 26,002