Income Taxes (Narrative) (Details) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | |||
|---|---|---|---|---|---|
Jun. 30, 2016 |
Jun. 30, 2015 |
Jun. 30, 2016 |
Jun. 30, 2015 |
Dec. 31, 2015 |
|
| Income Tax Contingency [Line Items] | |||||
| Effective income tax (percent) | 37.90% | 38.40% | 34.70% | 39.90% | |
| Deferred tax assets, net | $ 1,277,096 | $ 1,277,096 | $ 1,394,879 | ||
| Gross unrecognized tax benefits | 22,500 | 22,500 | 39,000 | ||
| Accrued interest and penalties on unrecognized tax benefits | 11,900 | 11,900 | $ 17,200 | ||
| Possible decrease in unrecognized tax benefits | $ 18,500 | $ 18,500 | |||
| Minimum | |||||
| Income Tax Contingency [Line Items] | |||||
| Income tax years under examination | 2005 | ||||
| Maximum | |||||
| Income Tax Contingency [Line Items] | |||||
| Income tax years under examination | 2016 | ||||