Pension and Other Retirement Plans - Amounts Recognized in Consolidated Balance Sheets (Details) - USD ($) $ in Thousands		Dec. 31, 2016	Dec. 31, 2015
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Employee compensation and benefits (1)	[1]	$ 0	$ 0
Pension obligations, net (2)	[2]	(444,401)	(456,073)
Postretirement medical, life and other benefits (2)	[2]	0	0
Net amount recognized		(444,401)	(456,073)
Other Postretirement Plans
Defined Benefit Plan Disclosure [Line Items]
Employee compensation and benefits (1)	[1]	(1,324)	(1,409)
Pension obligations, net (2)	[2]	0	0
Postretirement medical, life and other benefits (2)	[2]	(7,551)	(8,646)
Net amount recognized		$ (8,875)	$ (10,055)

[1] (1) Included in current liabilities within the Company’s Consolidated Balance Sheets.

[2] (2) Included in non-current liabilities within the Company’s Consolidated Balance Sheets.