Income Taxes Reconciliation of statutory federal income tax rate to effective income tax rate (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Contingency [Line Items]
Income taxes at federal statutory rate	35.00%	35.00%	35.00%
Effect of state and local income taxes, net of federal tax	3.30%	2.80%	3.00%
Deferred tax asset valuation allowance	(2.20%)	0.40%	(6.60%)
Tax contingencies	(1.30%)	0.10%	(1.40%)
Other	0.70%	1.20%	1.20%
Effective rate	35.50%	39.50%	31.20%
Maximum [Member]
Income Tax Contingency [Line Items]
Operating loss carryforwards, expiration dates	Jan. 01, 2032