Schedule II - Schedule of Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allowance for doubtful accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance January 1,	$ 6,118	$ 7,815	$ 9,078
Charged to Expenses (Benefit)	55,941	47,187	44,961
Write-offs/ Payments/ Other	(53,401)	(48,884)	(46,224)
Balance December 31,	8,658	6,118	7,815
Deferred tax assets—valuation allowance
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance January 1,	49,095	4,995	7,831
Charged to Expenses (Benefit)	(1,019)	44,100	(2,836)
Write-offs/ Payments/ Other	(394)	0	0
Balance December 31,	47,682	49,095	4,995
Allowance for obsolescence
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance January 1,	9,949	10,724	14,218
Charged to Expenses (Benefit)	1,148	(34)	(335)
Write-offs/ Payments/ Other	(1,660)	(741)	(3,159)
Balance December 31,	$ 9,437	$ 9,949	$ 10,724