CRJ flight crew reported failure of cockpit window in cruise flight. Flight diverted and landed uneventfully.

Narrative

En route at FL300; Cptain's forward cockpit window shattered. While cabin pressure remained normal; an immediate descent was requested as a precaution. 'Request an immediate descent for a broken window.' The response from the Center high-altitude sector controller: immediate descent clearance to FL240; soon revised to FL180. An expedited descent was performed with idle power and speed brakes fully extended; at normal descent speed (rather than increasing speed to Vmo / Mmo) due to the uncertain condition of the shattered window.As cabin pressure was holding; an 'Emergency' was not declared to the Center high-sector controller. However; after switching frequency to the low-altitude sector controller; a request to for more information accompanied a further descent clearance to 16;000 ft. As the aircraft is not equipped with ACARS or message-capable data link; company notification was attempted by e-mail. This notification attempt was later revealed to be unsuccessful due to an error in the company phone contacts file.After switching radio frequencies; further incremental descents from the Center low-altitude sector controller were also received without delay. Weather avoidance during the expedited descent was challenging with many CBs (Cumulonimbus) in the area. Once level at 8;000 ft.; and with cabin pressure remaining normal; continuing to destination at low altitude/airspeed was briefly considered; but rejected due to condition of the windscreen; convective weather in the area; and excessive (1+15) time en route.After consulting the Jeppesen FD Pro Low Altitude chart and the FMS; a diversion to ZZZ was requested. (FMS distance 56 NM; and the nearest airport having an FBO and scheduled commercial airline service). The decision to divert and land without undue delay was later validated by post-flight inspection that revealed both outer and inner window panes shattered.The response from Center to our request to divert was gratifying; with an immediate clearance direct to the airport. PF (Pilot Flying) continued to do an admirable job of avoiding CBs in the area while heading for the airport; once clear of weather; PM (Pilot Monitoring) left the cockpit to brief the passengers. After returning to the cockpit; PM began preparing the aircraft for landing. A second company e-mail notification of the diversion was attempted; but discontinued after seeing that the first e-mail had not been delivered due to the incorrect e-mail contact address.After switching radio frequencies to approach; further descents to 3;000 ft.; and then 2;000 ft. were received. At 2;000 ft. cabin differential pressure abruptly decreased to zero. With intent to avoid distracting PF from flying the aircraft; PM accomplished a silent review of the 'Descent Checklist.' With preparations for landing complete; sufficient time remained for a radio call to the FBO notifying them of our impending arrival and requesting services.An ILS approach was flown to an uneventful landing and taxi to the FBO.Upon deplaning; many pax expressed their appreciation for a safe arrival. A phone call to the company revealed that both dispatch and customer service were aware of the diversion. A second phone call to the approach control supervisor (phone number received from Ground Control after landing) revealed they had already obtained from Center the required information.Captain then joined the passengers in the FBO to answer questions. Company employee (traveling aboard the flight as a non-revenue passenger) rendered valuable assistance in communications between customer service and passengers. A maintenance ferry flight was briefly considered until local mechanics conducted an inspection of the shattered window. After their determination that both outer and inner panes were shattered; a maintenance ferry flight was no longer considered possible; and crew prepared to leave the aircraft. Possible lightning strike with a loud 'BANG' followed immediately by a zipper-like 'Brrrrrp' as the window shattered; scorch marks observed after. That said; a post-flight inspection did not show a lightning exit point; thus cause unknown.