Consolidated Balance Sheets (Unaudited) - NPC (Parenthetical) - $ / shares	Jun. 30, 2023	Dec. 31, 2022
Common stock, shares authorized	115,000,000	115,000,000
Common stock, shares issued	76,000,000	76,000,000
Common stock, shares outstanding	76,000,000	76,000,000
NPC
Common stock, par value (in dollars per share)	$ 1.00	$ 1.00
Common stock, shares authorized	1,000	1,000
Common stock, shares issued	1,000	1,000
Common stock, shares outstanding	1,000	1,000