Shareholder Report, Average Annual Return (Details)	6 Months Ended	12 Months Ended	60 Months Ended	120 Months Ended
Shareholder Report, Average Annual Return (Details)	Jun. 30, 2026	Jun. 30, 2026	Jun. 30, 2026	Jun. 30, 2026
Without Sales Load [Member] \| C000027865
Average Annual Return [Line Items]
Average Annual Return, Percent	1.02%	4.13%	0.14%	2.76%
Without Sales Load [Member] \| C000125779
Average Annual Return [Line Items]
Average Annual Return, Percent	1.70%	3.22%	4.60%	3.94%
Without Sales Load [Member] \| C000027854
Average Annual Return [Line Items]
Average Annual Return, Percent	0.89%	3.42%	3.65%	4.85%
Bloomberg U.S. Aggregate Bond Index
Average Annual Return [Line Items]
Average Annual Return, Percent	0.62%	3.79%	0.08%	1.54%
Bloomberg U.S. Aggregate Bond Index
Average Annual Return [Line Items]
Average Annual Return, Percent	0.62%	3.79%	0.08%	1.54%
Bloomberg U.S. Aggregate Bond Index
Average Annual Return [Line Items]
Average Annual Return, Percent	0.62%	3.79%	0.08%	1.54%
S&P UBS Leveraged Loan Index
Average Annual Return [Line Items]
Average Annual Return, Percent	1.38%	4.26%	5.94%	5.49%
Bloomberg U.S. Corporate High Yield Index
Average Annual Return [Line Items]
Average Annual Return, Percent	1.96%	5.91%	4.17%	5.81%