Income Taxes Components of Income Tax Expense (Details) - USD ($) $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2016	[1]	Sep. 30, 2016	[1]	Jun. 30, 2016	[1]	Mar. 31, 2016	[1]	Dec. 31, 2015	[1]	Sep. 30, 2015	[1]	Jun. 30, 2015	[1]	Mar. 31, 2015	[1]	Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Income Tax Expense Components [Line Items]
Deferred Income Tax Expense (Benefit) Continuing and Discontinued Operations																	$ 2,777		$ (4,575)		$ 5,058
Income Tax Expense (Benefit)	$ 7,247		$ 8,652		$ 7,626		$ 7,438		$ 5,638		$ 8,182		$ 8,000		$ 8,572		30,963	[2]	30,392	[2]	32,365	[2]
Income Tax Expense Components, Continuing Operations [Member]
Income Tax Expense Components [Line Items]
Current Federal Tax Expense (Benefit)																	20,237		25,631		20,557
Current State and Local Tax Expense (Benefit)																	7,778		9,183		7,254
Current Income Tax Expense (Benefit)																	28,015		34,814		27,811
Deferred Federal Income Tax Expense (Benefit)																	1,976		(3,185)		3,895
Deferred State and Local Income Tax Expense (Benefit)																	972		(1,237)		659
Deferred Income Tax Expense (Benefit) Continuing and Discontinued Operations																	2,948		(4,422)		4,554
Income Tax Expense (Benefit)																	$ 30,963		$ 30,392		$ 32,365

[1] Due to rounding, the sum of the four quarters may not add to the year to date total.

[2] The Company’s effective tax rate for 2016, 2015, and 2014 is not consistent due to earnings from tax-exempt investments, non-deductible compensation, state and local taxes, income tax credits and income attributable to noncontrolling interests having a different impact on the effective tax rate due primarily to the different levels of income before taxes in years 2016, 2015, and 2014. See Part II. Item 8. “Financial Statements and Supplementary Data - Note 17: Income Taxes” for additional details.