Long-Term Debt (Redemption Price) (Details) - Senior Notes [Member]	3 Months Ended
	Mar. 31, 2016
2015 [Member] | 5.625% Senior Unsecured Notes due 2020 [Member]
Redemption price as percent of the principal amount	104.219%
2016 [Member] | 5.625% Senior Unsecured Notes due 2020 [Member]
Redemption price as percent of the principal amount	102.813%
2017 [Member] | 5.625% Senior Unsecured Notes due 2020 [Member]
Redemption price as percent of the principal amount	101.406%
2017 [Member] | 5.625% Senior Unsecured Notes due 2022 [Member]
Redemption price as percent of the principal amount	104.219%
2018 and thereafter [Member] | 5.625% Senior Unsecured Notes due 2020 [Member]
Redemption price as percent of the principal amount	100.00%
2018 [Member] | 5.625% Senior Unsecured Notes due 2022 [Member]
Redemption price as percent of the principal amount	102.813%
2019 [Member] | 5.625% Senior Unsecured Notes due 2022 [Member]
Redemption price as percent of the principal amount	101.406%
2020 and thereafter [Member] | 5.625% Senior Unsecured Notes due 2022 [Member]
Redemption price as percent of the principal amount	100.00%