Income Taxes (Components of Income Tax Expense) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current:
Federal									$ 24,106	$ 16,769	$ 25,532
State									11,298	8,686	5,025
Total current expense									35,404	25,455	30,557
Deferred:
Federal									760	2,615	12,370
State									(1,174)	145	893
Total deferred expense (benefit)									(414)	2,760	13,263
Total income tax expense	$ 5,155	$ 7,941	$ 13,584	$ 8,310	$ 6,685	$ 8,956	$ 7,451	$ 5,123	$ 34,990	$ 28,215	$ 43,820