Stock-Based Compensation - Long-Term Performance-Based Plans - Additional (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Recognized non-cash stock-based compensation expense
Non-cash stock-based compensation expense recognized	$ 36,261	$ 29,941	$ 13,037
Outstanding awards pursuant to performance-based stock incentive plans
Performance Based Stock Options (in shares)	8,969,886
Weighted-Average Exercise Price (in dollars per share)	$ 40.34
Restricted Performance Units (in shares)	1,760,225	2,484,720	1,336,000	1,382,250
2019 LTIP
Recognized non-cash stock-based compensation expense
Non-cash stock-based compensation expense recognized	$ 3,534
Estimated Remaining Non-Cash, Stock-Based Compensation Expense
Remaining expense estimated to be recognized during 2016	14,122
Estimated contingent expense subsequent to 2016	26,410
Total estimated remaining expense over the term of plan	$ 40,532
Outstanding awards pursuant to performance-based stock incentive plans
Performance Based Stock Options (in shares)	4,296,000
Weighted-Average Exercise Price (in dollars per share)	$ 35.42
LTIP 2013
Recognized non-cash stock-based compensation expense
Non-cash stock-based compensation expense recognized	$ (2,471)	$ (321)	$ 2,565
Estimated Remaining Non-Cash, Stock-Based Compensation Expense
Estimated contingent expense subsequent to 2016	34,342
Total estimated remaining expense over the term of plan	$ 34,342
Outstanding awards pursuant to performance-based stock incentive plans
Performance Based Stock Options (in shares)	1,021,500
Weighted-Average Exercise Price (in dollars per share)	$ 41.35
LTIP 2017
Recognized non-cash stock-based compensation expense
Non-cash stock-based compensation expense recognized	$ 3,334	10,640
Estimated Remaining Non-Cash, Stock-Based Compensation Expense
Estimated contingent expense subsequent to 2016	20,910
Total estimated remaining expense over the term of plan	$ 20,910
Outstanding awards pursuant to performance-based stock incentive plans
Performance Based Stock Options (in shares)	2,512,386
Weighted-Average Exercise Price (in dollars per share)	$ 56.99
Other Employee Performance Awards
Recognized non-cash stock-based compensation expense
Non-cash stock-based compensation expense recognized	$ 17,945	7,549	1,424
Estimated Remaining Non-Cash, Stock-Based Compensation Expense
Remaining expense estimated to be recognized during 2016	17,946
Estimated contingent expense subsequent to 2016	64,313
Total estimated remaining expense over the term of plan	$ 82,259
Outstanding awards pursuant to performance-based stock incentive plans
Performance Based Stock Options (in shares)	1,140,000
Weighted-Average Exercise Price (in dollars per share)	$ 21.31
Restricted Performance Units (in shares)	1,215,500
Other Employee Performance Awards | Continuing operations [Member]
Recognized non-cash stock-based compensation expense
Non-cash stock-based compensation expense recognized	$ 22,342	$ 17,868	$ 3,989
Restricted Performance Units/Awards
Outstanding awards pursuant to performance-based stock incentive plans
Performance Based Stock Options (in shares)	1,800,000
Restricted Performance Units (in shares)	1,726,250	2,435,500	1,336,000
Restricted Performance Units/Awards | LTIP 2013
Outstanding awards pursuant to performance-based stock incentive plans
Restricted Performance Units (in shares)	510,750