CONDENSED CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY - 6 months ended Jun. 30, 2018 - USD ($) shares in Thousands, $ in Thousands	Total	Total Stockholders' Equity	Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (loss)	Non-controlling Interest	Common Class A Common Stock	Common Class B [Member] Common Stock	ATS Acquisition	ATS Acquisition Total Stockholders' Equity	ATS Acquisition Paid-in Capital	ATS Acquisition Retained Earnings
Dividends	$ 1,499,935	$ 1,499,935	$ 963,711	$ (536,224)
Conversion of Stock, Shares Converted	0						2,458	(2,458)
Acquisitionofi24	$ 15,049	15,049	(61,049)	(73,578)	$ (2,520)
Beginning balance (As Reported) at Dec. 31, 2017	5,495,840	5,494,301	4,642,128	854,824	(10,022)	$ 1,539	$ 2,470	$ 4,901
Beginning balance (Restatement Adjustment)									$ (3,753)	$ (3,753)	$ 23,101	$ (26,854)
Beginning balance (Restatement Adjustment, Impact of ASC 606)	12,666	12,666		12,666
Beginning balance at Dec. 31, 2017	5,504,753	5,503,214	4,665,229	840,636	(10,022)	1,539	2,470	4,901
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss attributable to stockholders	(226,806)	(226,806)		(226,806)
Net loss attributable to noncontrolling interests	(147)					(147)
Proceeds from (Payments to) Noncontrolling Interests	5,995					5,995
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss) Due to Settlements, Net of Tax	3,691	3,691			3,691
Pension liability adjustments, net of income taxes	4,267
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	576	576			576
Share-based compensation expense	33,849	33,849	33,849
Redeemable equity vested	(50,396)	(50,396)	(50,396)
Other changes to equity	(859)	(859)	(859)	0
Adoption of ASU No. 2018-02				2,163	(2,163)
Ending balance at Jun. 30, 2018	3,867,193	3,859,806	3,856,682	$ 6,191	$ (10,438)	$ 7,387	$ 4,928	$ 2,443
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Redeemable Equity Vested	$ (111,521)	$ (111,521)	$ (111,521)