Commitments and Contingencies Information Regarding Rental Commitments (Details 2) - USD ($) $ in Thousands		3 Months Ended
		Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Mar. 31, 2015
Property Subject to or Available for Operating Lease [Line Items]
Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals		$ 131,845
Percentage of Sublease Rentals due from Counterparty		35.00%
Operating Leases, Future Minimum Payments Due	[1]	$ 698,194
Commitments Related to Vacated and Subleased Space [Member]
Property Subject to or Available for Operating Lease [Line Items]
Valuation Allowances and Reserves, Balance		29,808			$ 31,745
Commitments Related to Vacated Space that Remains Vacant [Member]
Property Subject to or Available for Operating Lease [Line Items]
Valuation Allowances and Reserves, Balance		11,999			20,495
Operating Leases, Future Minimum Payments Due		21,727
Vacated Office Space [Member]
Property Subject to or Available for Operating Lease [Line Items]
Valuation Allowances and Reserves, Balance		41,807			$ 52,240	$ 45,939
Valuation Allowances and Reserves, Period Increase (Decrease)		$ (2,189)	$ (2,306)	$ (2,700)

[1] (1) Includes $636,653 in real estate and equipment leases and $61,541 in service and maintenance agreements.