Income Taxes - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Contingency [Line Items]
Additional deferred tax assets recognized		$ 98,078	$ 105,647
Reduction of income tax expense after realization of benefits		926
Accrued liabilities for interest and penalties related to uncertain tax positions		462	437	$ 469
Accrued interest and penalties, net of related federal tax effects		71	194	247
Reduction in income tax expense for reversal of accrued interest and penalties		345
Base-year bad debt reserves		165,800	165,800
Related deferred federal income tax liability		58,000	$ 58,000
New York State
Income Tax Contingency [Line Items]
Increase in net deferred tax asset				15,700
Corresponding reduction in income tax expense				$ 15,700
Reduction in income tax expense	$ 11,400
Elimination of valuation allowance which previously offset certain deferred tax assets	7,200
Additional deferred tax assets recognized	$ 4,200
Net operating loss carryforwards		171,900
New York City
Income Tax Contingency [Line Items]
Net operating loss carryforwards		$ 46,600