Indebtedness (Parenthetical) (Details) |
Dec. 31, 2016 |
Mar. 31, 2016 |
Dec. 31, 2015 |
Jun. 30, 2011 |
---|---|---|---|---|
2.75% Senior Convertible Notes [Member] | Convertible Notes due 2017 [Member] | ||||
Debt Instrument [Line Items] | ||||
Interest rate on convertible notes | 2.75% | 2.75% | 2.75% | |
2.25% Senior Convertible Notes [Member] | Convertible Notes due 2021 [Member] | ||||
Debt Instrument [Line Items] | ||||
Interest rate on convertible notes | 2.25% | 2.25% | 2.25% |