Stock-Based Compensation - Long-Term Performance-Based Plans - Additional (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Recognized non-cash stock-based compensation expense
Non-cash stock-based compensation expense recognized	$ 19,199	$ 34,153	$ 30,655
Outstanding awards pursuant to performance-based stock incentive plans
Performance Based Stock Options (in shares)	3,904,500
Weighted-Average Exercise Price (in dollars per share)	$ 28.03
Restricted Performance Units (in shares)	1,382,250	1,798,331	1,943,497	1,185,080
Continuing operations [Member]
Recognized non-cash stock-based compensation expense
Non-cash stock-based compensation expense recognized	$ 19,199	$ 34,153	$ 29,730
Discontinued operations [Member]
Recognized non-cash stock-based compensation expense
Non-cash stock-based compensation expense recognized			925
Long-Term Performance Based Plans
Recognized non-cash stock-based compensation expense
Non-cash stock-based compensation expense recognized	11,851	26,456	15,253
LTIP 2008
Recognized non-cash stock-based compensation expense
Non-cash stock-based compensation expense recognized			2,889
LTIP 2013
Estimated Remaining Non-Cash, Stock-Based Compensation Expense
Remaining expense estimated to be recognized during 2016	7,112
Estimated contingent expense subsequent to 2016	39,218
Total estimated remaining expense over the term of plan	46,330
Recognized non-cash stock-based compensation expense
Non-cash stock-based compensation expense recognized	$ 10,157	12,361	8,137
Outstanding awards pursuant to performance-based stock incentive plans
Performance Based Stock Options (in shares)	1,564,500
Weighted-Average Exercise Price (in dollars per share)	$ 42.63
Restricted Performance Units (in shares)	782,250
Other Employee Performance Awards
Estimated Remaining Non-Cash, Stock-Based Compensation Expense
Estimated contingent expense subsequent to 2016	$ 36,087
Total estimated remaining expense over the term of plan	36,087
Recognized non-cash stock-based compensation expense
Non-cash stock-based compensation expense recognized	$ 1,694	14,095	4,045
Outstanding awards pursuant to performance-based stock incentive plans
Performance Based Stock Options (in shares)	2,340,000
Weighted-Average Exercise Price (in dollars per share)	$ 18.27
Restricted Performance Units (in shares)	600,000
Other Employee Performance Awards | Continuing operations [Member]
Recognized non-cash stock-based compensation expense
Non-cash stock-based compensation expense recognized	$ 11,851	$ 26,456	15,071
Other Employee Performance Awards | Discontinued operations [Member]
Recognized non-cash stock-based compensation expense
Non-cash stock-based compensation expense recognized			$ 182