Debt - Cash Convertible Senior Subordinated Notes (Details) - USD ($)		1 Months Ended	12 Months Ended
	Mar. 16, 2015	Mar. 31, 2010	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Debt Disclosure [Abstract]
Issue of cash convertible senior subordinated notes		$ 375,000,000
Debt maturity date			Mar. 15, 2015
Payment of convertible notes	$ 119,300,000		$ 117,259,000	$ 0	$ 0
Payment of convertible notes, principal amount	117,300,000
Payment of convertible notes, interest portion	$ 2,100,000
Notes bear interest rate per year		3.50%
Date of commencing of notes			Sep. 15, 2010